To see the other types of publications on this topic, follow the link: Behavioral signaling.
Dissertations / Theses on the topic 'Behavioral signaling'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Behavioral signaling.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Rosenthal, Gil Guastoni. "The behavioral ecology of visual signaling in swordtails /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
Full text
2
Harris, Gareth P. "Behavioral State Modulates Olfactory Perception and Behavioral Response: Serotonergic and Peptidergic Signaling Interact to Modulate Aversive Olfactory Behaviors in Caenorhabditis elegans." University of Toledo / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1279300152.
Full text
3
McLaughlin, Ryan Joseph. "Prefrontal endocannabinoid signaling mediates neuroendocrine and behavioral coping responses to stress." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42054.
Full textAbstract:
Major depression is a heterogeneous disease often precipitated by dysfunction within the neuroendocrine stress circuitry, leading to profound deficits in prefrontocortical function. The endocannabinoid system has recently emerged as a vital component of the stress response; however, the mechanisms by which endocannabinoid signaling in the prefrontal cortex (PFC) modulates neuroendocrine and behavioral responses to stress has yet to be elucidated. In Chapter 2, genetic deletion of the CB₁ receptor prolonged corticosterone secretion following cessation of stress, which was recapitulated by CB₁ receptor antagonism within the medial PFC. Acute stress produced a delayed elevation in 2-arachidonoylglycerol (2-AG) content in the medial PFC that was reversed by glucocorticoid receptor antagonism. Immunohistochemical and electrophysiological data demonstrated the presence of CB₁ receptors in inhibitory-type terminals impinging upon principal neurons within layer V of the medial PFC. Furthermore, application of corticosterone to prefrontocortical slices suppressed γ-aminobutyric acid release onto layer V principal neurons, which was prevented by CB₁ receptor antagonism. Hence, the ability of glucocorticoids to terminate HPA axis activity is mediated by local recruitment of 2-AG in the medial PFC. In Chapter 3, forced swim stress rapidly suppressed anandamide (AEA) content in the medial PFC. Local inhibition of AEA hydrolysis decreased passive coping and increased active coping strategies in the forced swim test (FST) in a CB₁ receptor-dependent and serotonin-mediated manner. Furthermore, local inhibition of AEA hydrolysis increased the firing rate of serotonin neurons, suggesting that prefrontocortical AEA signaling modulates stress coping behaviors via regulation of serotonergic neurotransmission. In Chapter 4, rats exposed to chronic unpredictable stress (CUS) displayed increased CB₁ receptor binding specifically within the ventromedial PFC. CUS exposure increased passive coping and decreased active coping strategies in the FST, which was further augmented by ventromedial PFC CB₁ receptor blockade. Thus, the increase in CB₁ receptor binding observed in the ventromedial PFC of CUS-exposed rodents serves a compensatory role that maintains proactive coping strategies under chronically stressful conditions. Collectively, this body of research indicates that prefrontocortical endocannabinoid signaling is a critical mediator of neuroendocrine and behavioral stress responses and may represent an appealing target for future therapeutic strategies aimed at combating stress-related disorders.
4
Burston, James Justin. "Antipsychotic modulation of cannabinoid signaling in the CNS and behavioral correlates." Thesis, University of the West of England, Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.522523.
Full text
5
Banerjee, Navonil. "Temporal Organization of Behavioral States through Local Neuromodulation in C. elegans." eScholarship@UMMS, 2012. http://escholarship.umassmed.edu/gsbs_diss/892.
Full textAbstract:
Neuropeptide signaling play critical roles in maintaining distinct behavioral states and orchestrating transitions between them. However, elucidating the mechanisms underlying neuropeptide modulation of neural circuits in vivo remains a major challenge. The nematode Caenorhabditis elegans serves as an excellent model organism to study neuropeptide signaling mechanisms encoded in relatively simple neural circuits. We have used the C. elegans egg-laying circuit as a model to understand how neuropeptide signaling modifies circuit activity to generate opposing behavioral outcomes. C. elegans egg-laying behavior is composed of alternating cycles of two states – short bursts of egg deposition (active phases) and prolonged periods of quiescence (inactive phases). We have identified two neuropeptides (NLP-7 and FLP-11) that are locally released from a group of neurosecretory cells (uv1) and coordinate the temporal organization of egglaying by prolonging the duration of inactive phases. These neuropeptides regulate activity within the core circuit by inhibiting serotonergic transmission between its individual components (HSN motorneurons and Vm2 vulval muscles). This inhibition is achieved at least in part, by reducing synaptic vesicle abundance in the HSN synaptic regions. To identify potential downstream signaling components that mediate the actions of these neuropeptides, we have performed a forward genetic screen and have identified a strong candidate. In addition, we are trying to identify the receptor(s) of these neuropeptides by using a candidate gene approach. Together, we demonstrate that local neuropeptide signaling maintains the periodicity of distinct behavioral states by regulating serotonergic transmission in the core neural circuit.
6
Banerjee, Navonil. "Temporal Organization of Behavioral States through Local Neuromodulation in C. elegans." eScholarship@UMMS, 2016. https://escholarship.umassmed.edu/gsbs_diss/892.
Full textAbstract:
Neuropeptide signaling play critical roles in maintaining distinct behavioral states and orchestrating transitions between them. However, elucidating the mechanisms underlying neuropeptide modulation of neural circuits in vivo remains a major challenge. The nematode Caenorhabditis elegans serves as an excellent model organism to study neuropeptide signaling mechanisms encoded in relatively simple neural circuits. We have used the C. elegans egg-laying circuit as a model to understand how neuropeptide signaling modifies circuit activity to generate opposing behavioral outcomes. C. elegans egg-laying behavior is composed of alternating cycles of two states – short bursts of egg deposition (active phases) and prolonged periods of quiescence (inactive phases). We have identified two neuropeptides (NLP-7 and FLP-11) that are locally released from a group of neurosecretory cells (uv1) and coordinate the temporal organization of egglaying by prolonging the duration of inactive phases. These neuropeptides regulate activity within the core circuit by inhibiting serotonergic transmission between its individual components (HSN motorneurons and Vm2 vulval muscles). This inhibition is achieved at least in part, by reducing synaptic vesicle abundance in the HSN synaptic regions. To identify potential downstream signaling components that mediate the actions of these neuropeptides, we have performed a forward genetic screen and have identified a strong candidate. In addition, we are trying to identify the receptor(s) of these neuropeptides by using a candidate gene approach. Together, we demonstrate that local neuropeptide signaling maintains the periodicity of distinct behavioral states by regulating serotonergic transmission in the core neural circuit.
7
Huskey, Richard Wayne. "Does Signaling Theory Account for Aggressive Behavior in Video Games?" Thesis, University of California, Santa Barbara, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1555260.
Full textAbstract:
Signaling theory originated in evolutionary biology and explains the mechanisms behind the honest communication of information between organisms. Communication scholars are increasingly turning to signaling theory as a way to test evolutionary explanations for human behavior. The present study tests if receiver-dependent costly signals can be used to predict the moment of aggressive behavior in video game environments. High status (but not high trait aggression) male subjects were fastest to engage in combat against a low voice pitch male opponent - but only when subject skill was high. This result underscores the importance of video game skill as a variable of interest as well as the need for video games researchers to tease out when real-world behaviors map to video game contexts.
8
Oakes, Mitchell Duane. "Uncovering Cannabinoid Signaling in C. elegans: A New Platform to Study the Effects of Medicinal Cannabis." University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1532948536948823.
Full text
9
Gibbons, Christopher M. "The referentiality of chimpanzee vocal signaling behavioral and acoustic analysis of food barks /." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1173219994.
Full text
10
Long, Jessica B. "The behavioral functions of stimuli signaling transitions across rich and lean schedules of reinforcement." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4444.
Full textAbstract:
Thesis (M.S.)--West Virginia University, 2005.Title from document title page. Document formatted into pages; contains vi, 39 p. : ill. Includes abstract. Includes bibliographical references (p. 37-39).
11
Hough, Alexander R. "Understanding and Improving Coordination Efficiency in the Minimum Effort Game: Counterfactual- and Behavioral-Based Nudging and Cognitive Modeling." Wright State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=wright1621265522828309.
Full text
12
Wilhite, Kyle. "Sexual Selection in the Spring Peeper, Pseudacris crucifier , and Multimodal Signaling in the Tungara frog, Physalaemus pustulosus." Thesis, Salisbury University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1525306.
Full textAbstract:
Communication facilitates almost every social interaction between organisms and this communication is especially important for mate acquisition. Anuran amphibians are an excellent model system to study mate choice behaviors and sexual selection. In this work I recorded male calls of the spring peeper, Pseudacris crucifer, between two populations (Maryland and Louisiana) and analyzed call parameters such as frequency, duration, and rise and fall time. I found differences in the frequency and the frequency sweep of the calls. I conducted choice experiments to test female mating preferences in the Louisiana population and found a preference for longer calls over short calls. Females did not express a preference for frequency, frequency sweep, or local (LA) versus foreign (MD) calls. I also conducted multimodal signaling experiments on the túngara frog, Physalaemus pustulosus. I used natural calls and a robotic túngara frog to determine how females assess different signal modalities (auditory versus visual). I tested previously established attractive calls against unattractive calls, paired with the robo-frog and inflating vocal sac, to see if the visual stimulus would modulate the attractiveness of the call. The presence of the vocal sac did not make the unattractive call more attractive. The vocal sac may have important implications for localization in a more complex environment but here, it did not act as a mate attracting signal. This study provides the ground work necessary for multimodal signaling in spring peepers and for complex sensory environment choice tests in the túngara frog.
13
Koon, Alex C. "Autoregulatory and Paracrine Control of Synaptic and Behavioral Plasticity by Dual Modes of Octopaminergic Signaling: A Dissertation." eScholarship@UMMS, 2011. https://escholarship.umassmed.edu/gsbs_diss/572.
Full textAbstract:
Synaptic plasticity—the ability of a synapse to change—is fundamental to basic brain function and behavioral adaptation. Studying the mechanisms of synaptic plasticity benefits our understanding of the formation of neuronal connections and circuitry, which has great implications in the field of learning and memory and the studies of numerous human diseases.
The Drosophila larval neuromuscular junction (NMJ) system is a powerful system for studying synaptic plasticity. The NMJ consists of at least two different types of motorneurons innervating the body wall muscles. Type I motorneurons controls muscle contraction using glutamate as the neurotransmitter, while type II are modulatory neurons that contain octopamine. Octopamine is a potent modulator of behavior in invertebrates. Nevertheless, its function at the synapse is poorly understood.
In my thesis research, I investigated the role of octopamine in synaptic plasticity using the Drosophila NMJ system. Preliminary observations indicate that increased larval locomotion during starvation results in an increase of filopodia-like structures at type II terminals. These structures, which we termed as “synaptopods” in our previous studies, contain synaptic proteins and can mature into type II synapses. I demonstrated that this outgrowth of type II terminals is dependent on activity and octopamine. Mutations and genetic manipulations affecting the production of octopamine decrease synaptopods, whereas increase of type II activity or exogenous application of octopamine increase synaptopods. Interestingly, I found that the type II octopaminergic neurons have an absolute dependence on activity for their innervation of the muscles. Blocking activity in these neurons throughout development results in no type II synapses at the NMJ, whereas blocking activity after the formation of synapses results in gradual degradation of type II terminals.
Next, I examined the autoregulatory mechanism underlying the octopamine-induced synaptic growth in octopaminergic neurons. I discovered that this positive-feedback mechanism depends on an octopamine autoreceptor, Octß2R. This receptor in turn activates a cAMP- and CREB-dependent pathway that is required in the octopamine-induction of synaptopods. Furthermore, I demonstrated that this octopaminergic autoregulatory mechanism is necessary for the larva to properly increase its locomotor activity during starvation.
Thirdly, I investigated the possibility that type II innervation might regulate type I synaptic growth through octopamine. We found that ablation, blocking of type II activity, or the absence of octopamine results in reduced type I outgrowth, and this paracrine signaling is mediated by Octß2R which is also present in type I motorneurons.
Lastly, the function of another octopamine receptor, Octß1R, was examined. In contrast to Octß2R, Octß1R is inhibitory to synaptic growth. I demonstrated that the inhibitory effect of this receptor is likely accomplished through the inhibitory G-protein Goα. Similar to Octß2R, Octß1R also regulates the synaptic growth of both type I and type II motorneurons in a cell-autonomous manner. The inhibitory function of this receptor potentially breaks the positive feedback loop mediated by Octß2R, allowing the animal to reset its neurons when the environment is favorable.
In summary, the research presented in this thesis has unraveled both autoregulatory and paracrine mechanisms in which octopamine modulates synaptic and behavior plasticity through excitatory and inhibitory receptors.
14
Tomaselli, Giovanni. "Role of pregnenolone derivative AEF0117 on the regulation of CB1 signaling that mediates behavioral effects of THC." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0122.
Full textAbstract:
Le cannabis sativa est l'une des drogues les plus consommées dans le monde. Le THC, sa principale composante psychoactive, représente un facteur de risque de pathologies mentales, telles que le trouble de la consommation de cannabis, la dépendance et la psychose. Le THC a un effet biphasique, de fortes doses de THC provoquent une hypoactivité et une aversion, tandis que de faibles doses de THC provoquent une hyperactivité et une récompense. Le THC agit sur le récepteur aux cannabinoïdes de type 1 (CB1), dont la signalisation est biaisée avec différents transducteurs pouvant véhiculer une voie spécifique selon différentes conditions. Il a été prouvé que la signalisation biaisée est pertinente dans la découverte de médicaments et la compréhension de la signalisation CB1 est essentielle pour le développement de médicaments à base de cannabinoïdes. Même si il a été montré que différentes doses de THC entraînent des effets comportementaux, cellulaires et moléculaires différents, le lien entre ces phénomènes n'a jamais été étudié.En outre, il a été découvert que la pregnénolone (PREG) est un modulateur allostérique endogène biaisé du CB1, en étant un inhibiteur de signalisation spécifique du récepteur CB1 (CB1-SSi) et capable de bloquer des comportements induits par le THC. Comme la PREG est un précurseur de stéroïde, son administration à forte dose peut induire la production de stéroïdes, avec d'éventuels effets secondaires.Ainsi, dans un but thérapeutique, des composés CB1-SSi analogues à la PREG ont été synthétisés, ayant le même potentiel thérapeutique que la PREG, mais sans être métabolisés en stéroïdes. Le CB1-SSi étudié ici est le composé CB1-SSi leader, l’AEF0117.Le premier objectif de ce travail était de comprendre les voies de signalisation intracellulaires selon des doses faibles, moyennes et élevées de THC, conduisant à respectivement l'hyperlocomotion, l'asociabilité et l'hypolocomotion chez la souris.Le second objectif était de comprendre le mécanisme d'action de l’AEF0117 et sa capacité à bloquer les effets comportementaux et moléculaires du THC à faibles, moyennes et fortes doses.La thèse est divisée en cinq parties. L'introduction sert à préfacer les concepts du système endocannabinoïde, ainsi que l'abus de cannabis chez l'homme et les effets comportementaux du THC chez la souris, comme l'hyperlocomotion, l'asociabilité et l'hypolocomotion. L'état de l'art de la signalisation CB1 impliquant le système CB1 biaisé est décrit avec un accent particulier sur les inhibiteurs spécifiques de la signalisation CB1 (CB1-SSi), en particulier la pregnénolone endogène (PREG), et son analogue synthétique, l’AEF0117.L'article Zanese*, Tomaselli* et al, 2020 (publié dans J. Neurosci. Methods) porte sur la validation de la technique analytique à haut débit (AlphaLISA) de choix dans cette étude pour la détection de la phosphorylation des protéines dans les lysats de tissu cérébral.L'article de Tomaselli et al. (à soumettre) est consacré à l'étude de faible dose de THC qui provoque l'hyperlocomotion chez la souris. Les principales données ont révélé que le THC via CB1 recrute la voie de signalisation β-Arrestin1-PI3K-Akt-GSK3β, dans les zones du cerveau riches en CB1 et pertinentes pour l'activité locomotrice (NAc, Str, CB), qui conduit à l'hyperlocomotion. En outre, PREG et AEF0117 peuvent bloquer l'hyperlocomotion et les modifications de la signalisation CB1 induite par le THC.La troisième partie représente les études sur les effets du THC à des doses moyennes et élevées qui induisent respectivement un comportement asocial et une hypolocomotion. Chaque dose de THC induit des altérations spécifiques des voies de signalisation intracellulaires CB1 et le traitement avec l’AEF0117 réverse les deux comportements.La discussion générale aborde ensuite le rôle des voies CB1 spécifiques dans la dépendance et la psychose induites par le THC, et propose un mécanisme d'action pour les composés CB1-SSi, dont l’AEF0117Cannabis sativa is among the most abused drugs worldwide. THC, its main psychoactive component, represents a risk factor of several mental pathologies, such as cannabis use disorder, addiction, and psychosis. Being a biphasic drug, high doses of THC cause hypoactivity and aversion, whereas low doses of THC cause hyperactivity and reward. THC acts on the type-1 cannabinoid receptor (CB1), one of the most abundant G-protein coupled-receptors (GPCRs) in the brain, whose signaling is biased, meaning that different transducers can carry specific pathway following different conditions. Biased signaling was proven to be extremely relevant in drug discovery and understanding CB1 signaling in pathologic conditions is essential for cannabinoid-based drug development. It is known that different doses of THC bring along different behavioral, cellular, and molecular outcomes. However, the link between those phenomena has never been investigated.Thus, for a therapeutic purpose PREG-like CB1-SSi compounds have been synthetized that share the same PREG therapeutic potential, but cannot be metabolized in downstream steroids. The CB1-SSi studied in the current work is the CB1-SSi lead compound, AEF0117.The first aim of the current work was to understand the intracellular signaling pathways following low, medium, and high doses of THC, leading to three distinct known behavioral outputs in mice, hyperlocomotion, asociability, and hypolocomotion, respectively.The second aim of the thesis was to understand the mechanism of action of AEF0117, and its capability to block the behavioral and molecular effects of THC at low, medium, and high doses.The doctoral dissertation is divided into five main parts. The introduction serves to preface the concepts of the endocannabinoid system, as well as cannabis abuse in humans and the counterpart behavioral outcomes of THC in mice, including hyperlocomotion, asociability, and hypolocomotion. The state of the art of CB1 signaling involving the biased CB1 system is described with particular emphasis on CB1 Signaling Specific Inhibitors (CB1-SSi), in particular the endogenous pregnenolone (PREG), and its synthetic analogue, the lead CB1-SSi compound, AEF0117.The article Zanese*, Tomaselli* et al., 2020 (published in J. Neurosci. Methods) oversees the validation of the high throughput analytical technique (AlphaLISA) of choice in this study for detection of protein phosphorylation in brain tissue lysates.The article Tomaselli et al. (to be submitted), is devoted to the studies of the low dose of THC that causes hyperlocomotion, with the discovering of its related intracellular CB1 signaling pathway, along with the signaling transducer involved in the CB1-rich brain areas relevant for locomotor activity (NAc, Str, CB). The main data revealed that THC via CB1 recruits the β-Arrestin1-PI3K-Akt-GSK3β signaling pathway that lead to hyperlocomotion. Furthermore, both PREG and AEF0117 were able to block the THC-induced hyperlocomotion and altered signaling in mice.The third part of the data represent studies on the effects of THC at medium and high doses that induce asocial behavior and hypolocomotion, respectively. Each dose of THC induced specific alterations in the CB1intracellular signaling pathways in the most CB1-rich brain areas, and the treatment with AEF0117 rescued both behaviors.The general discussion then addresses conclusions and perspectives, highlighting the role of specific CB1 pathways in THC-induced addiction and psychosis, and proposes a mechanism of action for CB1-SSi compounds, including AEF0117
15
Estrada, Christina M. "Examining the Effects of Estradiol Signaling in the Medial Amygdala on Emotionality and Cognition in Female Rats." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1447688747.
Full text
16
Cheung, Amy. "The Role of Neurexins in Serotonin Signaling and Complex Behaviors." eScholarship@UMMS, 2021. https://escholarship.umassmed.edu/gsbs_diss/1134.
Full textAbstract:
Extensive serotonin (5-HT) fiber innervation throughout the brain corroborates 5-HT’s modulatory role in numerous behaviors including social behavior, emotion regulation, and learning and memory. Abnormal brain 5-HT levels and function are implicated in Autism Spectrum Disorder (ASD) which often co-occurs with other neuropsychiatric conditions. While 5-HT therapeutics are used to treat ASD, variable improvements in symptomatology require further investigation of 5-HT-mediated pathology. Neurexins (Nrxns) are presynaptic cell adhesion molecules that maintain synapse function for proper neural circuit assembly. Given that aberrant Nrxn and 5-HT function independently contribute to signaling pathology and behavioral impairments, it is critical to understand how Nrxn-mediated 5-HT neurotransmission participates in pathological mechanisms underlying ASD.
Using fluorescence in situ hybridization, I found that the three Nrxn genes (Nrxn1, Nrxn2, and Nrxn3) are differentially expressed in 5-HT neurons in the dorsal raphe nucleus (DRN) and median raphe nucleus which contain the primary source of 5-HT neurons in the brain. Our lab generated a mouse model with selective deletion of Nrxns in 5-HT neurons to investigate the function of Nrxns in 5-HT signaling. The loss of Nrxns at 5-HT release sites reduced 5-HT release in the DRN and hippocampus and altered 5-HT innervation in specific brain regions. The lack of 5-HTergic Nrxns also reduced sociability and increased depressive-like behavior in males. This mouse model provides mechanisms to shed new light on 5-HT neurotransmission in the generation of complex behaviors.
17
Regan, Samantha. "The role of Latrophilin-3 in activity, cognition, and dopaminergic signaling in Sprague Dawley rats." University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1623240391187149.
Full text
18
Park, Ji S. "CYCLIC GMP: A SATIETY SIGNAL IN C. ELEGANS." VCU Scholars Compass, 2015. http://scholarscompass.vcu.edu/etd/3851.
Full textAbstract:
Appetite control and satiety mechanisms help animals maintain energy homeostasis; however, these mechanisms can be misregulated, leading to overweight and obesity. Caenorhabditis elegans is an excellent model system to study appetite and satiety because of its conserved behavioral aspects of satiety and conserved molecular mechanisms. ASI senses nutrition and its activity is required for the behavioral state of satiety quiescence. The purpose of this thesis project was to elucidate the function of cGMP signaling in ASI by looking at behavioral effects from the pharmacological use of sildenafil (Viagra), a PDE inhibitor, and the effects on ASI activation from mutating guanylyl cyclase DAF-11. Sildenafil treatment increases satiety quiescence and decreases fat storage in a PDE-dependent manner. The daf-11 mutation decreased overall fluorescence intensity of ASI activation and the frequency at which ASI activated by about 50% compared to wild-type worms, suggesting that DAF-11 plays an important role in ASI to promote satiety.
19
Fick, Patrik, and Mattias Nordenadler. "Är aktiesplit fortfarande en hitt? : En eventstudie om aktiesplitar och överavkastning tidigt 2000-tal kontra sent 2010-tal." Thesis, Södertörns högskola, Företagsekonomi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-43771.
Full textAbstract:
Effektiviteten på de finansiella marknaderna är något som studerats utifrån många olika perspektiv. Vad den effektiva marknadshypotesen i sin helhet påstår är att all information som tillkommer snabbt inkorporeras i aktiepriset utan att investerare har haft en chans att agera, vilket omöjliggör arbitragemöjligheter och således en chans till en positiv abnormal avkastning. Denna studies sätt att undersöka detta fenomen är att studera avkastningen vid genomförandet av en aktiesplit på stockholmsbörsen för att se om någon positiv abnormal föreligger. Studien är gjord i form av en eventstudie där aktiesplitar som genomförts under åren 2000 - 2006 och 2015 - 2019, där de undersökts och genomgått statistiska tester. Dessa olika tidsperioderna har till en början analyserats var för sig för att sedan jämföras mot varandra för att undersöka ifall skillnader föreligger. Studien har kommit fram till att positiv abnormal avkastning förekommer vid genomförandet av en aktiesplit på stockholmsbörsen och kan även se tendenser på skillnader mellan de olika undersökningsperioderna.The efficiency of the financial markets is something that has been studied through many perspectives. What the efficient market hypothesis says is that new information that reaches the market fast incorporates in the stock price without any chance for the investors to act on it. This results in no chance in arbitrage opportunities hence no chance to positive abnormal return. This study's way of examining this phenomenon was to study the return on the implementation of stock splits which has been implemented on the swedish stock exchange to see if any positive abnormal return exists. This event study has examined stock splits during the periods of year 2000 - 2006 and 2015 - 2019 and statistical tests have been made. These different periods of time have at first been examined by themselves before comparing them with each other to see if there might be any different between them. This study shows that there are significant positive abnormal returns associated with stock returns on the swidish stock exchange during both periods. The study also shows tendencies of that the abnormal returns differ between the two time periods.
20
Frazier, Hilaree N. "Exploring the Role of Insulin Receptor Signaling in Hippocampal Learning and Memory, Neuronal Calcium Dysregulation, and Glucose Metabolism." UKnowledge, 2019. https://uknowledge.uky.edu/pharmacol_etds/32.
Full textAbstract:
In the late 90’s, emerging evidence revealed that the brain is insulin-sensitive, highlighted by broad expression of brain-specific insulin receptors and reports of circulating brain insulin. Contemporary literature robustly supports the role of insulin signaling in normal brain function and suggests that insulin-related processes diminish with aging, evidenced by decreased signaling markers, reduced insulin receptor density, and lower levels of insulin transport across the blood-brain barrier. In the context of pathological cognitive decline, clinical trials using intranasal insulin delivery have reported positive outcomes on memory and learning in patients with mild cognitive decline or early-stage Alzheimer’s disease. However, while the importance of insulin and its related actions in the brain are robustly supported, the distinct mechanisms and pathways that mediate these effects remain unclear.
To address this, I conducted a series of experiments exploring the impact of insulin on memory and learning in two models: primary hippocampal cell cultures and the Fisher 344 animal model of aging. These studies attempted to identify relationships between insulin receptor signaling, neuronal gene expression, glucose metabolism, and calcium homeostasis in the hippocampus using either expression of a constitutively active human insulin receptor or administration of intranasal insulin. The following dissertation summarizes this work and provides valuable insights into the potential pathways mediating these relationships. Of note, intranasal studies reported that insulin is able to significantly alter gene expression patterns in the hippocampus of both young and aged rats following chronic, repeated exposure to the ligand. In cell culture, constitutive insulin signaling correlated with significantly elevated neuronal glucose uptake and utilization, as well as with significant alterations in the overall expression and localization of the neuron-specific glucose transporter 3. Interestingly, continued activity of the insulin receptor did not appear to alter voltage-gated calcium channels in hippocampal neurons despite prior evidence of the ligand’s role in other calcium-related processes.
The results reported in this manuscript suggest that in the brain, insulin may be involved in a myriad of complex and dynamic events dependent on numerous variables, such as age, length of the exposure, and/or the insulin formulation used. Nevertheless, this work highlights the validity of using insulin to ameliorate age-related cognitive decline and supports the need for further studies exploring alternative approaches to enhance insulin receptor signaling in the brain.
21
Papazoglou, Ioannis. "Cross-talk between insulin and serotonin signaling in the brain : Involvement of the PI3K/Akt pathway and behavioral consequences in models of insulin resistance." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA11T039/document.
Full textAbstract:
L’insuline et la sérotonine (5-HT) sont deux acteurs majeurs du maintien de l’homéostasie énergétique, fonction placée sous le contrôle de l’hypothalamus. En ciblant cette région, l’insuline remplit de nombreuses fonctions métaboliques via l’activation de la voie PI3K/Akt. La 5-HT exercent des effets biologiques similaires mais les voies de signalisation impliquées dans ces processus étaient jusqu’alors mal connues. De plus, il avait été démontré que la 5-HT est capable d’activer la voie PI3K/Akt/GSK3β dans l’hippocampe, mécanisme sous-tendant potentiellement les effets antidépresseurs du neurotransmetteur. Les principaux objectifs de cette thèse étaient d’étudier 1/ l’activation de la voie PI3K/Akt par la 5-HT dans l’hypothalamus de rats diabétiques (modèle Goto-Kakizaki) et chercher un potentiel dialogue avec l’insuline and 2/ les mécanismes sous-tendant l’induction de la dépression par une alimentation hyperlipidique, par l’analyse de la phosphorylation d’Akt et GSK3β sous l’action de l’insuline, de la leptine et de la 5-HT dans l’hippocampe de rat.Ici on montre que 1/ la 5-HT stimule la voie PI3K/Akt dans l’hypothalamus et que la phosphorylation d’Akt induite par la 5-HT est atténuée dans des conditions d’insulino-résistance, suggérant l’existence d’un dialogue entre les voies de signalisation de l’insuline et de la 5-HT. Par ailleurs, nos résultats indiquent qu’une alimentation hyperlipidique induit un comportement dépressif réversible chez le rat, qui pourrait impliquer la voie PI3K/Akt/GSK3β dans les neurones subgranulaires du gyrus denté. La mise en évidence d’un dialogue entre les voies de signalisation de la 5-HT, de la leptine et de l’insuline au niveau central enrichit nos connaissances sur le rôle de ces facteurs dans la régulation de l’homéostasie énergétique et de l’humeur, et propose un lien moléculaire entre diabète de type 2, obésité et dépressionInsulin and serotonin (5-HT) are two key players in the maintenance of energy homeostasis which is controlled by the hypothalamus. In this brain region, insulin mediates numerous metabolic effects via the activation of the PI3K/Akt signaling pathway. 5-HT exerts similar biological properties by acting in the hypothalamus but the signaling pathways accountable for these effects are still unclear. Moreover, it has been reported that 5-HT induces the activation of the PI3K/Akt pathway in the hippocampus and the inhibition of GSK3β, suggesting this action as a potential mechanism for the antidepressant effects of this neurotransmitter.The main objectives of this thesis were to study 1/ the serotonin-induced activation of the PI3K/Akt in the hypothalamus of wild type and diabetic rats (Goto-Kakizaki model) and search a potential cross-talk with insulin and, 2/ the mechanisms underlying the high-fat diet induced depression by investigating the role of the phosphorylation of Akt and GSK3β by 5-HT, insulin and leptin in the hippocampus of rats.Here, we show that 5-HT triggers the PI3K/Akt signaling pathway in the rat hypothalamus, and that this activation is attenuated in insulin-resistant conditions, suggesting a cross-talk between insulin and 5-HT. Moreover, we reported that high-fat diet feeding induces a reversible depressive-like behavior, which may involve the PI3K/Akt/GSK3β pathway in subgranular neurons of the dentate gyrus. In conclusion, the activation of the PI3K/Akt pathway and its target GSK3β by 5-HT in the hypothalamus and in the dentate gyrus, respectively, can be impaired in insulin-/leptin-resistant states, which may underlie a link between metabolic diseases and depression
22
Måhl, Frida, and Ellinore Vinberg. "Går det att förutspå framtiden med hjälp av aktieutdelning? : Resultat och lönsamhet på Nasdaq Stockholm över 20 år." Thesis, Uppsala universitet, Företagsekonomiska institutionen, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-393089.
Full textAbstract:
Inom finansiell ekonomi finns en seglivad teori om att utdelningsändringar innehåller information om framtida ekonomiska resultat. Aktiemarknaden reagerar i enlighet med teorin på så vis att aktiekursen stiger när utdelningen höjs, och tvärtom, vilket har dokumenterats i ett flertal studier. Bakom aktiemarknadens reaktion på den ändrade utdelningen borde det finnas ett positivt samband mellan utdelningsändringar och framtida ekonomiska resultat. Problemet är att förekomsten av ett sådant samband är högst tveksam; tidigare empiriska studier har trots flerfaldiga försök inte funnit övertygande argument för förekomsten av ett samband mellan utdelningsändringar och framtida ekonomiska resultat. Syftet med denna uppsats är att undersöka om det finns ett positiv samband mellan utdelningsändringar och framtida resultat och lönsamhet. Det empiriska underlaget är företag på Nasdaq Stockholm under perioden 1999–2018. Sambandet eftersöks med hjälp av en regressionsmodell i vilken vi kontrollerar för det icke-linjära beteendeet hos resultat och lönsamhet. Vi finner ett par statistiskt signifikanta resultat som påvisar samband mellan sänkta utdelningar och framtida resultat och lönsamhet; dessa är dock så pass små att de saknar ekonomisk relevans. Vårt resultat är således i linje med tidigare empiriska studier och stödjer därmed inte teori om utdelningssignalering.Within the area of corporate finance, there exists a persistent theory that revolves around the idea that changes in terms of corporate dividend may yield information regarding future financial results. The stock market is known to fluctuate in accordance with this theory by ways of indicating increased share prices in close correspondence to increased dividend, and vice versa, which has also been documented in several previous studies. This relation between the stock market’s reaction to the change in dividend should by all accounts point to a positive correlation between dividend changes and future financial results. Yet, this relation has to this point been proved to be highly doubtful. Previous empirical studies have not been able to find any convincing arguments that such a relationship exists. The purpose of this essay is to investigate if there in fact exists a relationship between dividend changes and future earnings and profitability. The empirical data for this study consists of the companies listed on the Nasdaq Stockholm during the period of 1999 to 2018. This proposed relationship has been investigated by the use of a regression model, in which we have examined the known non-linear behaviour of earnings and profitability. By this method we have found a few results of statistical significance that do seem to indicate a relation, between lowered dividend and future financial outcomes. However, while still statistically significant, these results are not economically significant. Our results are therefore considered to be in line with previous research and does not offer any further support for the proposed theory of the dividend signaling hypothesis.
23
Måhl, Frida, and Ellinore Vinberg. "Går det att förutspå framtiden med hjälp av aktieutdelning? : Resultat och lönsamhet på Nasdaq Stockholm över 20 år." Thesis, Uppsala universitet, Företagsekonomiska institutionen, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-390891.
Full textAbstract:
Inom finansiell ekonomi finns en seglivad teori om att utdelningsändringar innehåller information om framtida ekonomiska resultat. Aktiemarknaden reagerar i enlighet med teorin på så vis att aktiekursen stiger när utdelningen höjs, och tvärtom, vilket har dokumenterats i ett flertal studier. Bakom aktiemarknadens reaktion på den ändrade utdelningen borde det finnas ett positivt samband mellan utdelningsändringar och framtida ekonomiska resultat. Problemet är att förekomsten av ett sådant samband är högst tveksam; tidigare empiriska studier har trots flerfaldiga försök inte funnit övertygande argument för förekomsten av ett samband mellan utdelningsändringar och framtida ekonomiska resultat. Syftet med denna uppsats är att undersöka om det finns ett positiv samband mellan utdelningsändringar och framtida resultat och lönsamhet. Det empiriska underlaget är företag på Nasdaq Stockholm under perioden 1999–2018. Sambandet eftersöks med hjälp av en regressionsmodell i vilken vi kontrollerar för det icke-linjära beteendeet hos resultat och lönsamhet. Vi finner ett par statistiskt signifikanta resultat som påvisar samband mellan sänkta utdelningar och framtida resultat och lönsamhet; dessa är dock så pass små att de saknar ekonomisk relevans. Vårt resultat är således i linje med tidigare empiriska studier och stödjer därmed inte teori om utdelningssignalering.Within the area of corporate finance, there exists a persistent theory that revolves around the idea that changes in terms of corporate dividend may yield information regarding future financial results. The stock market is known to fluctuate in accordance with this theory by ways of indicating increased share prices in close correspondence to increased dividend, and vice versa, which has also been documented in several previous studies. This relation between the stock market’s reaction to the change in dividend should by all accounts point to a positive correlation between dividend changes and future financial results. Yet, this relation has to this point been proved to be highly doubtful. Previous empirical studies have not been able to find any convincing arguments that such a relationship exists. The purpose of this essay is to investigate if there in fact exists a relationship between dividend changes and future earnings and profitability. The empirical data for this study consists of the companies listed on the Nasdaq Stockholm during the period of 1999 to 2018. This proposed relationship has been investigated by the use of a regression model, in which we have examined the known non-linear behaviour of earnings and profitability. By this method we have found a few results of statistical significance that do seem to indicate a relation, between lowered dividend and future financial outcomes. However, while still statistically significant, these results are not economically significant. Our results are therefore considered to be in line with previous research and does not offer any further support for the proposed theory of the dividend signaling hypothesis.
24
Florman, Jeremy T. "Neuroendocrine Modulation of Complex Behavior and Physiology in C. elegans." eScholarship@UMMS, 2020. https://escholarship.umassmed.edu/gsbs_diss/1109.
Full textAbstract:
To survive, animals must adapt to a complex and challenging world in a way that is flexible and responsive, while maintaining internal homeostasis. Neuromodulators provide a means to systemically alter behavioral or physiological state based on intrinsic or extrinsic cues, however dysregulated neuroendocrine signaling has negative consequences for fitness and survival. Here I examine neuroendocrine function and dysfunction using the escape response in Caenorhabditis elegans. The RFamide neuropeptide FLP-18 is a co-transmitter with the monoamine tyramine and functions both synergistically and antagonistically to tyramine in coordinating escape behavior. Using behavioral analysis and calcium imaging, I show that FLP-18 functions primarily through the G-protein coupled receptor (GPCR) NPR-5 to increase calcium levels in muscle, enhancing locomotion rate, bending and reversal behavior during the escape response.
Furthermore, I examine the relationship between persistent acute stress and resilience using repeated activation of the escape response as a model of neuroendocrine dysregulation. Repeated activation of the escape response shortens lifespan and renders animals more susceptible to thermal, oxidative, and nutritional stress. Tyramine release is necessary and sufficient for this effect and activity of the tyraminergic RIM neurons is differentially regulated by acute versus long-term stressors. Impaired stress resistance requires both the GPCR TYRA-3 in the intestine and intestinal neuropeptide release. Activation of the insulin receptor DAF-2 is downstream of TYRA-3 and inhibits the transcription factors DAF-16/FOXO, SKN-1/Nrf2 and HSF-1, linking monoamine signaling in acute stress to the insulin signaling pathway and impaired resilience to long-term stressors.
25
Hale, Jennifer Ann. "The Role of Male Vocal Signals During Male-Male Competition and Female Mate Choice in Greater Prairie-Chickens (Tympanuchus cupido)." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1365786099.
Full text
26
Trakadis, John. "The vervet regulator of G protein signaling 4 (RGS4) gene, a candidate gene for quantifiable behavioral dimensions associated with psychopathology : sequence, bioinformatic analysis, and association study of a novel polymorphism with social isolation." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84101.
Full textAbstract:
Regulators of G-protein coupled signaling (RGS) accelerate GTP hydrolysis and consequently influence signal termination. The RGS-4 gene has recently been reported to be implicated in a wide range of neuropsychiatric disorders including schizophrenia, Alzheimer's disease and addictions.In this study, the vervet RGS-4 gene was sequenced on a CEQ 8000 genetic analysis system (Beckman Coulter) and characterized using molecular and bioinformatic tools. The obtained vervet sequence overall showed 95.3% sequence identity with the human RGS4 gene.
Thereafter, SNPs in the region encompassing the proximal promoter, exon 1 and the first 450 bp of intron 1 were identified by direct sequencing of 8 unrelated individuals. One of the identified SNPs, +35 [A/G], was genotyped in 155 juvenile vervets previously phenotyped for personality traits, including social isolation. Although preliminary association analysis fails to attain statistical significance (p=0.074), the sample size is small. Additional genotyping of phenotypically defined individuals needs to be undertaken.
27
Mohr, Sascha Janina. "Costly signaling and generous behavior." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/6278.
Full textAbstract:
This thesis explores the use of generous behaviour as a costly signal to convey information about an unobservable social characteristic to other individuals in one's social environment. Building on recent contributions in this spirit, I develop a theoretical framework that contrasts signaling activities without social benefits with activities that benefit the observers in situations in which individuals compete for access to a scarce social good. The objective of the first part of the thesis is to characterize the possible separating equilibria in each case. While one obtains a multiplicity of equilibria when the agents employ neutral signals to convey information, one can make a unique prediction with respect to the individuals' equilibrium behaviour if they use beneficial signaling activities, the agents are of two discrete types, behave symmetrically within their respective types, and the observers of the signals adopt non-decreasing beliefs vis-à-vis the signalers' relative quality. In view of their sharp divergence, the second part of the thesis investigates experimentally the precision of these predictions. The results provide support for many elements of the theory. Among others, the behaviour of individuals in the treatments with beneficent signals is much more closely in line with the theoretical predictions than expected given the complexity of their behavioural implications, especially when it comes to the similarity of the participants' behaviour within them. Behaviour in the treatment with neutral signals, in turn, is consistent with multiple equilibria. The final part of the thesis explores what kind of signaling activity individuals trying to communicate their intentions to potential interaction partners will use in various social settings if given a choice. To this end, the framework developed in the first part is extended to allow the signalers to choose endogenously a signal from a “menu” of signaling activities rather than exogenously prescribing a messaging tool. Besides revealing that the uniqueness result of the framework without choice no longer obtains, the results indicate that the players may, under some conditions, opt for inefficient signals.
28
Waterbury, L. A. "A mathematical model of biological signaling networks and network characteristics correlated with signaling behavior." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1446094.
Full text
29
Christy, Sean M. "Essays on the economics of signaling goodness." Diss., Online access via UMI:, 2006.
Find full text
30
Lynch, Joseph Francis III. "Estrogenic Modulation of Fear Generalization." Kent State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=kent1466095867.
Full text
31
Thompson, Lauren. "Intracellular Signaling Contributions to Behaviors Relevant to Nicotine Addiction." VCU Scholars Compass, 2011. http://scholarscompass.vcu.edu/etd/253.
Full textAbstract:
Nicotine is the primary addictive substance in tobacco, and most smokers who quit will relapse within a year. Evidence shows that cigarette craving increases over time, termed “incubation.” The purpose of these studies was to see if protracted abstinence from chronic nicotine increases rat self-administration, an animal model with good face validity for human tobacco use, and if nicotine self-administration during daily exposure/after 8+ days of abstinence is regulated by extracellular signal-regulated kinase (ERK) signaling in the nucleus accumbens (NAc) shell or anterior cingulate cortex (PFC). ERK kinase inhibitor U0126 was infused in the NAc shell or PFC of Long Evans rats immediately prior to daily self-administration sessions and following 8+ days of abstinence. U0126 in the PFC decreased responding for nicotine during daily sessions. Following 8+ days of abstinence, animals showed a robust increase in responding for nicotine, blocked by U0126 in the NAc shell, but not the PFC. Western blots revealed that nicotine treatment decreased levels of a substrate of ERK, ribosomal s6 kinase (RSK), in the NAc shell and increased it in the PFC, which occurred independent of abstinence period. In contrast, levels of RSK were increased in the NAc shell following a nicotine challenge during the abstinence period. In summary, our data show that the ERK signaling pathway plays a vital role in nicotine addiction during daily nicotine exposure and following periods of abstinence.
32
Guo, Juanli Cooper Lyndon F. "The involement of Wnt signaling in osteoblastic cell behavior." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2008. http://dc.lib.unc.edu/u?/etd,1622.
Full textAbstract:
Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2008.Title from electronic title page (viewed Sep. 16, 2008). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Curriculum of Oral Biology School of Dentistry." Discipline: Oral Biology; Department/School: Dentistry.
33
Chin, Jason M. "Moral uncertainty promotes prosocial behavior : exploring the self-signaling motivation for prosocial behavior." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/28003.
Full textAbstract:
Self-signaling theory posits that individuals engage in prosocial behavior in order to gain positive information about the self. Previous self-regulatory approaches to prosocial behavior have primarily focused on helping as means to self-repair (e.g., the negative state relief model), or as a means to stay self-consistent (e.g., self-verification theory), thus overlooking the motivation to obtain self-knowledge. Four studies tested a key prediction of self-signaling theory, that uncertainty about the self as a good and moral person should increase prosocial behavior, while certainty should decrease it. Study one used a correlational design to examine the relationship between personal uncertainty and volunteerism. Study two manipulated uncertainty about a positive moral characteristic and measured subsequent agreement to help. Study three examined the effect of uncertainty about a negative moral trait on helping behavior. Finally, study four manipulated both uncertainty, and the valence of self-information, while measuring charitable donations. All four studies find the hypothesized positive relationship between uncertainty and prosocial behavior. These findings support the idea that individuals help in order to gain information indicating they are good and virtuous, thus decreasing uncertainty about the self. Limitations, implications, and future directions are discussed.
34
Guignion, Cassandra Ann. "Behavioural displays, acoustic and chemosensory communication in the Middle Island tusked weta, Motuweta isolata (Orthoptera: Anostostomatidae)." Thesis, University of Canterbury. Biological Sciences, 2005. http://hdl.handle.net/10092/1408.
Full textAbstract:
Three methods of communication were examined in the Middle Island tusked weta, Motuweta isolata (Orthoptera: Anostostomatidae); defence behaviour, acoustic and chemosensory signalling. Previous studies had been limited to basic autecology and anecdotal evidence. This study was undertaken to understand the behaviours of this species to assist in conservation efforts. Defensive behaviours were elicited through repeated stimulation while aggressive behaviours were acquired through male-male battles. Femoro-abdominal stridulation was induced within both situations. Defensive stridulation functioned as alarm behaviour and was often accompanied by a visual display. Agonistic stridulation was executed by the eventual winner of combat. Aggressive battles were a progression of behavioural units of increasing risk on injury until an individual was determined the winner. Acoustic analysis was preformed on stridulations observed in aggressive and defensive behaviours. Stridulation was a broad band signal covering a range well above 16 kHz and possibly into the ultrasound range (>20 kHz). Two different forms of stridulation were identified; click train sound and hiss sound. High speed frame-by-frame analysis of stridulation and scanning electron micrographs of the abdomen and medial femur deciphered the mechanism and found the interaction of the cuticle to be unique among weta. Strikingly, micrographs also revealed two morphologies of abdominal projections; truncated ridges and columnar pegs. Both these points were not previously observed. Y-maze and partition tests were utilized for evidence of chemosensory signalling, while gas chromatography-mass spectrometry identified faecal volatiles in M. iisolata and 4 other weta species in a parallel study. Through partition experiments, evidence exists for a species-specific volatile pheromone and a sex-specific chemo-tactile pheromone. Dimethylsulphide, (CH3)2S, was present in the faeces of all 5 weta species, and may be produced by the individual.
35
McKay, Ailsa J. "Central vasopressin signalling and aggressive behaviour." Thesis, University of Edinburgh, 2008. http://hdl.handle.net/1842/4194.
Full textAbstract:
Although many signalling molecules appear relevant to the production of complex behaviours, those that are important to the physiological regulation of behaviour, and so those that characterise individual styles of behaviour, are unknown. Vasopressin is the strongest candidate regulator of social behaviour. Experiments were carried out in consideration that vasopressin may directly regulate aggressive behaviour in lactating rats. Patterns of immediate early gene expression during/subsequent to aggressive behaviour suggested specific neural circuits may have significant direct regulatory influence over particular behaviours, and that activation of the V1b vasopressin receptor, in these circuits, may contribute to this putative regulatory signalling. In situ hybridisation studies indicated that patterns of vasopressin release, rather than receptor expression, might be important for any peripartum changes in behaviour driven by vasopressin. Although their relative importance is unknown, central actions of vasopressin may exert a strong regulatory influence over a range of behaviours, across a range of species.
36
Herent, Coralie. "Respiratory Adaption to Running Exercise : A Behavioral and Neuronal Circuits Study in Mice Absent Phasing of Respiratory and Locomotor Rhythms in Running Mice Control of Orienting Movements and Locomotion by Projection-Defined Subsets of Brainstem V2a Neurons Afadin Signaling at the Spinal Neuroepithelium Regulates Central Canal Formation and Gait Selection." Thesis, université Paris-Saclay, 2021. http://www.theses.fr/2021UPASL001.
Full textAbstract:
Pendant la course, la ventilation augmente pour compenser la demande énergétique accrue. Le substrat, soupçonné neuronal, de cette hyperpnée à l'exercice est néanmoins toujours méconnu. Pour le caractériser, nous avons, chez la souris, examiné les interactions entre i) mouvements des membres et cycles respiratoires, et ii) réseaux neuronaux locomoteur et respiratoire. Tout d’abord, en combinant enregistrements électromyographiques (EMG) du diaphragme combinés au suivi vidéo des membres pendant la course, nous montrons que, pour une large gamme de vitesses sur un tapis roulant, la fréquence respiratoire augmente jusqu'à une valeur fixe, indépendante des vitesses de course. Surtout, les inspirations ne sont pas temporellement synchronisées avec les foulées, indiquant que l'hyperpnée à l'exercice peut opérer sans signaux phasiques provenant des retours sensoriels des membres. Nous avons ensuite cherché à identifier, au sein des centres locomoteurs, les neurones déclencheurs de cette hyperpnée, ainsi que leurs cibles dans les centres respiratoires. En combinant enregistrements EMG, traçages viraux et interférences fonctionnelles, nous montrons d’une part que le principal centre de l'initiation locomotrice (la région locomotrice mésencéphalique, MLR) peut réguler à la hausse la respiration, pendant, et même avant, la course. Cet effet repose sur des projections directes de la MLR vers le générateur inspiratoire principal, le complexe préBötzinger. D'autre part, nous montrons que les circuits locomoteurs de la moelle épinière lombaire ont également une action excitatrice sur l'activité respiratoire. Cette voie ascendante cible néanmoins un autre groupe respiratoire, le noyau rétrotrapézoïde. Ce travail met ainsi en évidence la nature multifonctionnelle des centres locomoteurs, et souligne l'existence de multiples voies neuronales capables d’augmenter la respiration pendant, voire avant, la courseDuring running, ventilation increases to match the augmented energetic demand. Yet the presumed neuronal substrates for this running hyperpnea have remained elusive. To fill this gap, we have, in mice, examined the interactions between i) limb movements and respiratory cycles, and ii) locomotor and respiratory neural networks. First, by combining electromyographic recordings (EMG) of the diaphragm with limb video-tracking in running mice, we show that, for a wide range of trotting speeds on a treadmill, breathing rate increases to a fixed value, irrespective of running speeds. Importantly, breaths are never temporally synchronized to strides, highlighting that exercise hyperpnea can operate without phasic signals from limb sensory feedbacks. We next sought to identify candidate trigger neurons in the locomotor central network, and their partners in respiratory centers. Combining EMG recordings, viral tracing, and activity interference tools, we first show that the prime supraspinal center for locomotor initiation (the mesencephalic locomotor region, MLR) can upregulate breathing during, and even before, running. Indeed, the MLR contacts directly and modulates the main inspiratory generator, the preBötzinger complex. We show that the lumbar locomotor circuits also have an excitatory action onto respiratory activity, but that this ascending drive targets another essential respiratory group, the retrotrapezoid nucleus. This work highlights the multifunctional nature of locomotor command and executive centers, and points to multiple neuronal pathways capable of upregulating breathing during, or possibly even prior to, running
37
Hebets, Eileen Anne. "Evolution and function of complex signaling in spider courtship behavior." Diss., The University of Arizona, 2002. http://hdl.handle.net/10150/279966.
Full textAbstract:
Complex signaling, while common throughout the animal kingdom, is poorly understood and generally understudied. This dissertation provides a framework from which one can approach studies of complex signal function. The semantics involved in studies of signal evolution and complex signaling are discussed and complex signaling is broken down into two categories: multiple signals and multimodal signals. While single signals ultimately reflect the pressures of both tactical and strategic design, so must complex signals. I explore hypotheses relating to the function of complex signaling in terms of both tactical and strategic design pressures and then explore hypotheses allowing for the possibility of inter-signal interactions. Predictions of some tactical design hypotheses of complex signaling suggest that multimodal signals can act independently, as back-ups to each other in the presence of environmental noise, or they can interact in a variety of ways. I tested the tactical back-up hypothesis, among others, using the bimodal signaling wolf spider Schizocosa uetzi. Results suggest that the signals are not independent and that there is an inter-signal interaction in which the vibratory signal redirects and focuses a female's attention to the visual signal. A comparative approach explored the tactical and strategic design components of multimodal signaling across three species of Schizocosa, one unimodal signaling species (S. avida, vibration only) and two bimodally signaling species (S. uetzi and S. stridulans). Signal non-independence was found for both bimodally signaling species but the pattern of inter-signal interaction differed between the species. Inter-population interactions between divergent populations that possess independent, derived traits can also be affected by inter-signal interactions. Results from an empirical study using two divergent populations of the jumping spider Habronattus pugillis in inter-populational reciprocal crosses were compared to predictions of different models of sexual selection. Our results show a xenophilic mating preference with one population of females mating more frequently with foreign males than local males, while the second population of females showed no such difference. While this pattern is inconsistent with Fisherian selection and does not completely fit the predictions of pure sensory exploitation, it is completely consistent with one pattern predicted from a process of antagonistic coevolution.
38
Noble, Jason. "The evolution of animal communication systems : questions of function examined through simulation." Thesis, University of Sussex, 1998. https://eprints.soton.ac.uk/265236/.
Full textAbstract:
Simulated evolution is used as a tool for investigating the selective pressures that have influenced the design of animal signalling systems. The biological literature on communication is first reviewed: central concepts such as the handicap principle and the view of signalling as manipulation are discussed. The equation of “biological function” with “adaptive value” is then defended, along with a workable definition of communication. Evolutionary simulation models are advocated as a way of testing the coherence of a given theory. Contra some ALife enthusiasts, simulations are not alternate worlds worthy of independent study; in fact they fit naturally into a Quinean picture of scientific knowledge as a web of modifiable propositions. Existing simulation work on the evolution of communication is reviewed: much of it consists of simple proofs of concept that fail to make connections with existing theory. A particular model (MacLennan & Burghardt, 1994) of the evolution of referential communication in a co-operative context is replicated and critiqued in detail. Evolutionary simulations are then presented that cover a range of ecological scenarios; the first is a general model of food- and alarm-calling. In such situations signallers and receivers can have common or conflicting interests; the model allows us to test the idea that a conflict of interests will lead to an arms race of ever more costly signals, whereas common interests will result in signals that are as cheap as possible. The second model is concerned with communication during aggressive interactions. Many animals use signals to settle contests, thus avoiding the costs associated with fighting. Conventional game-theoretic results suggest that the signalling of aggression or of strength will not be evolutionarily stable unless it is physically unfakeable, but some recent models imply that cost-free, arbitrary signals can be reliable indicators of both intent and ability. The simulation, which features continuous-time perception of the opponent’s strategy, is an attempt to settle the question. The third model deals with sexual signalling, i.e., elaborate displays that are designed to persuade members of the opposite sex to mate. The results clarify the question of whether such displays are the pointless result of runaway sexual selection, or whether they function as honest and costly indicators of genetic quality. The models predict the evolution of reliable communication in a surprisingly narrow range of circumstances; a serious gap remains between these predictions and the ethological data. Future directions for simulation work are discussed.
39
Chen, Zhunan. "Molecular and Circuit Mechanisms of Insulin Signaling in Caenorhabditis elegans." Thesis, Harvard University, 2014. http://dissertations.umi.com/gsas.harvard:11302.
Full textAbstract:
Insulin signaling is highly conserved across animals, and is known for its ubiquitous function in all aspects of animal physiology. Despite its relatively well-studied role in metabolism and energy expenditure, how it is involved in learning and memory remains a mystery, due to the complex nature of the nervous system. In this thesis, I have used C. elegans, a tractable model organism with a sophisticated behavioral repertoire, to investigate molecular and cellular mechanisms of insulin signaling in learning.
40
Zhang, Ke-You. "Brain Signaling Mechanisms Through Which Dopamine Stimulates Maternal Behavior in Rats." Thesis, Boston College, 2008. http://hdl.handle.net/2345/537.
Full textAbstract:
Thesis advisor: Michael NumanThis paper will review research from our laboratory dealing with the neural basis of maternal behavior in rats. Specifically, my work investigates hypothalamic interaction with the mesolimbic dopamine system and the regulation of maternal responsiveness. Recent evidence has shown that increased dopamine activity in the nucleus accumbens, a major terminus of the mesolimbic dopamine pathway, results in a facilitation of maternal behavior in female rats who have been partially primed by hormones. However, the way in which dopamine and hormones act on these neural circuits is unclear. We hypothesize that one of these hormones, estradiol, acts on the MPOA and mesolimbic dopamine system through similar intracellular mechanisms as dopamine. My research goals are twofold: (1) to discern which G-protein coupled pathway dopamine utilizes to act in the nucleus accumbens and (2) to investigate whether estradiol is having rapid effects at the cell membrane and whether these effects are mediated by G-protein coupled receptors
Thesis (BA) — Boston College, 2008
Submitted to: Boston College. College of Arts and Sciences
Discipline: Psychology
Discipline: College Honors Program
41
Lammers, Marc O. "The behavior and broadband acoustic signaling of Hawaiʻian spinner dolphins (Stenella longirostris)." Thesis, University of Hawaii at Manoa, 2003. http://hdl.handle.net/10125/3058.
Full textAbstract:
This dissertation explores the design of dolphin social acoustic signals by addressing the question: how have the signals used by these animals been adapted to the physical, sensory and social environments they inhabit? To obtain answers to this question, the behavior and acoustic signals of spinner dolphins (Stenella longirostris) and spotted dolphins (Stenella frontalis) were examined. A rhythmic pattern of behavior is described for a population of spinner dolphins resident off the island of O'ahu. The population is tied to both trophic and physiographical resources associated with the island's coastline, where groups fuse and fragment in predicable patterns over the course of a daily cycle of activity and rest. Acoustic signals are thought to playa critical role in the coordination of animals within and between groups. A broadband analysis of the whistles and burst pulses of these two species reveals that they span a much broader range of frequencies than typically discussed in the literature. A considerable amount of energy is found in the higher frequency harmonics of whistles, as well as in the ultrasonic bands of burst pulses. Many burst pulses in fact have energy exclusively at ultrasonic frequencies and are thus inaudible to human hearing. Most if not all of the frequency hearing sensitivity typical for dolphins appears to be exploited in the design of their social acoustic signals. Evidence is also presented on the directionality of whistles together with a discussion on how the directional transmission of harmonics may provide important cues to listening animals about the orientation and direction of movement of a signaler. The "mixed-directionality" of dolphin whistles is proposed as a signal design feature that may be very important for the coordination of individuals within groups. Finally, a discussion is presented on how these findings fit together to provide a more complete picture of the nature of dolphin social acoustic signals. Their functional design is considered along with the features that make them well suited for echolocation and communication underwater. A roadmap is provided for future investigators who wish to further explore the design of dolphin social acoustic signals.Thesis (Ph. D.)--University of Hawaii at Manoa, 2003.
Mode of access: World Wide Web.
Includes bibliographical references.
Electronic reproduction.
Also available by subscription via World Wide Web
xvii, 187 leaves, bound ill. 29 cm
42
Dodson, Alexis. "Motley Views: Evolutionary Impact of Audience Perception on Morphology and Behavior in Two Jumping Spiders, Synemosyna formica & Habronattus pyrrithrix." University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1627658456447556.
Full text
43
Leach, Prescott Tarn. "NICOTINE MODULATION OF THYROID HORMONE SIGNALING AND ITS CONTRIBUTION TO COGNITION." Diss., Temple University Libraries, 2014. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/265971.
Full textAbstract:
PsychologyPh.D.
Cigarette smoking is common despite its adverse effects on health, including disruptions to endocrine function. Thyroid hormones may specifically be affected by nicotine exposure through cigarette smoke. The present work begins with a thorough analysis of the literature on thyroid hormones, their contribution to cognition and synaptic plasticity as well as evidence supporting an interaction between nicotine and thyroid signaling. Cigarette smoking/nicotine may disrupt thyroid function in women of reproductive age, heavy smokers, and those prone to thyroid dysfunction due to pre-existing conditions, and these populations would benefit from careful monitoring of their thyroid function. Nicotine also affects cognition and this may drive both the development and maintenance of nicotine addiction. Acute nicotine enhances maladaptive drug-context associations, likely contributing to the development of addiction. The present work evaluates the functional contribution of thyroid receptors (TRs) (ß and α1) to the effect of acute nicotine on hippocampus-dependent memory using a contextual fear conditioning paradigm. It was hypothesized that TRs would be critical for the acute effects of nicotine on contextual fear conditioning. Mice lacking the TRβ and TRα1 gene (KOs) and wildtype littermates (WTs) were administered acute nicotine prior to contextual fear conditioning and results indicated the selective involvement of TRβ in nicotine-enhanced hippocampus-dependent learning. Further examination confirmed select hippocampal TR activation during nicotine enhancement of hippocampus-dependent learning. Withdrawal from chronic nicotine disrupts cognition, leading to continued use and relapse in subjects attempting to quit smoking. Withdrawal from chronic nicotine may induce the development of a hypothyroid condition that could contribute to nicotine withdrawal-related symptoms such as impaired attention and memory. In support, analysis of serum thyroid hormone levels after chronic and withdrawal from chronic nicotine treatment revealed that nicotine withdrawal reduces thyroid hormone levels. Normalizing thyroid hormone levels may therefore represent a novel therapeutic target for ameliorating nicotine withdrawal-associated cognitive deficits. In support of this, supplemental thyroid hormone not only enhanced contextual and cued fear conditioning when administered alone, but also completely abolished nicotine withdrawal-associated deficits in contextual fear conditioning. These results suggest that careful monitoring of thyroid function is warranted, especially in subjects susceptible to the negative effects of nicotine on thyroid hormone levels, and smoking cessation attempts may benefit from successful treatment of thyroid dysfunction.
Temple University--Theses
44
Criswell, Joni M. "Multimodal Communication in the Panamanian Golden Frog (Atelopus zeteki)." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1228224476.
Full text
45
Stepniewski, Tomasz Maciej 1988. "Unraveling the complex signaling behavior of neurotransmitters and their receptors in the brain." Doctoral thesis, Universitat Pompeu Fabra, 2020. http://hdl.handle.net/10803/668308.
Full textAbstract:
G protein-coupled receptors (GPCRs) are the main acceptors of neurotransmitters, and thus play an important role in communication between neurons. Because of this they are an attractive drug target for multiple neurodegenerative and neuropsychiatric disorders.
The primary function of GPCRs is to initiate diverse intracellular signaling cascades in response to extracellular events, like neurotransmitter binding. Despite the wealth of available biochemical data, the structural foundations of GPCR activity remain poorly understood. Such insights would not only expand our knowledge of those receptors, but also facilitate the design of safer and more efficient drugs.
Here, using several computational approaches, we propose structural mechanisms that explain GPCR in vitro data. We unravel features GPCR functionality at multiple levels of action including ligandreceptor interactions, allosteric signal transmission as well as posttranslational modifications. Our results identify phenomena potentially conserved among GPCRs that advance our understanding of this relevant receptor family.Los receptores acoplados a proteína G (en inglés GPCRs) son los principales receptores de neurotransmisores, teniendo un papel importante en la comunicación neuronal. Por esto, se los considera una atractiva diana farmacológica en múltiples trastornos neurodegenerativos y neuropsiquiátricos. El rol primario de los GPCRs es iniciar múltiples cascadas de señalización intracelular en respuesta a eventos extracelulares. A pesar de la vasta información bioquímica disponible, los fundamentos estructurales de la actividad de GPCRs no se comprenden totalmente. Estos fundamentos, no sólo podrían expandir nuestro conocimiento de los receptores, sino que podrían facilitar el diseño de farmacos más seguros y eficaces. Utilizando varios enfoques computacionales, proponemos mecanismos estructurales que explican los resultados in vitro de los GPCRs. Desciframos elementos de la funcionalidad de GPCRs en múltiples niveles, incluyendo interacciones ligando-receptor, transmisión de señales alostérica y modificaciones post-traduccionales. Nuestros resultados identifican fenómenos potencialmente conservados entre los GPCRs, ampliando nuestro conocimiento de esta relevante familia de receptores.
46
Klempin, Friederike [Verfasser]. "Signaling pathways linking behavior to neurogenesis in healthy brain and disease / Friederike Klempin." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2020. http://d-nb.info/1209543435/34.
Full text
47
Blundon, Malachi Andrew. "Using Gel Based Proteomics to Study Signaling, Phsyiology, and Behavior in Drosophilia Melanogaster." Research Showcase @ CMU, 2017. http://repository.cmu.edu/dissertations/1078.
Full text
48
Reynolds, Anna R. "Gαq-ASSOCIATED SIGNALING PROMOTES NEUROADAPTATION TO ETHANOL AND WITHDRAWAL-ASSOCIATED HIPPOCAMPAL DAMAGE." UKnowledge, 2015. http://uknowledge.uky.edu/psychology_etds/74.
Full textAbstract:
Prolonged, heavy consumption of alcohol produces marked neuroadaptations in excitatory neurotransmission. These effects are accelerated following patterns of intermittent heavy drinking wherein periods of heavy consumption are followed by periods of abstinence. Studies have shown that neuroadaptive changes in the glutamatergic N-methyl-D-aspartate (NMDA) receptor produces excitotoxicity during periods of withdrawal; however, upstream targets were not adequately characterized. The present studies sought to identify these targets by assessing the role of group 1 metabotropic glutamate receptors (mGluR) and intracellular calcium in promoting cytotoxicity of hippocampal cell layers in vitro. It was hypothesized that ethanol-induced activity of mGluR1-and-5 contributes to hippocampal cytotoxicity and promotes the behavioral effects of withdrawal in vivo. In order to identify and test this theory, rat hippocampal explants were co-exposed to chronic intermittent ethanol exposure with or without the addition of a group 1 mGluR antagonist to assess cytotoxicity in neuronal cell types. In a second study, adult male rodents were co-exposed to chronic intermittent ethanol exposure with or without the addition of an mGluR5 antagonist to assess the role of these receptors in the development of dependence as reflected in withdrawal behaviors. Together, these studies help to identify and screen toxicity of putative pharmacotherapies for the treatment of ethanol dependence in the clinical population.
49
Åman, Isabelle. "Störningar i ledarhundens arbete : Orsak och konsekvenser." Thesis, Linnéuniversitetet, Institutionen för biologi och miljö (BOM), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-53534.
Full textAbstract:
Aggressivitet är ett vanligt förekommande beteende hos många arter och kan signaleras via både vokalisering och visuella signaler. Beteendet kan grunda sig i exempelvis dominans, konkurrens om en partner eller på att individen försvarar en resurs eller ett revir. För omkring 15 000 år sedan domesticerades vargar Canis lupus, vilket resulterade i underarten hund Canis familiaris och genom ett gediget avelsarbete finns det idag över 400 godkända hundraser. I Sverige finns det omkring 300 aktiva ledarhundar i tjänst och varje år utbildas runt 40 nya hundar som ska komma att arbeta med en ledarhundsförare. Syftet med denna studie var att se i vilken frekvens och på vilket sätt som ledarhundar för synskadade blir störda när de är i tjänst ute i det offentliga rummet dvs. på allmän plats. För att inhämta data utfördes en enkätundersökning där 18 ledarhundsförare beskrev en till två typsituationer av störningar från andra hundar som uppkommer i ledarhundens arbete. Närmare 90 procent av ledarhundsförarna angav att en eller flera störningar inträffat, där utfall var den vanligaste typen av störning följt av aktiv lek och attacker. Majoriteten av de utsatta ledarhundarna i denna studie var hanar av rasen labrador retriever. Ett flertal av ledarhundarna fick psykiska och/eller fysiska skador i samband med störningen, vilket ledde till att de fick tas ur tjänst tillfälligt. Angreppen kan ha grundat sig i bristande kommunikation då ledarhunden var i tjänst och fokuserad på sin uppgift. Resultaten baserades på ett begränsat antal svarande, vilket medför att resultaten kanske inte är representativa för hur situationen ser ut för Sveriges ledarhundar överlag men de indikerar på att problem med störningar finns. Denna studie är den första i sitt slag att utföras i Sverige och lämnar plats åt ytterligare forskning på området.Aggression is a common behavior among many species and can be signaled through both vocalization and visual signals. The behavior may be based on dominance, competition for a partner or because the individual defends a resource or a territory. Around 15 000 years ago the wolf Canis lupus was domesticated, which resulted in the subspecies dog Canis familiaris and through an extensive breeding program there are currently over 400 recognized breeds. In Sweden there are about 300 active guide dogs in service and every year around 40 new dogs are trained, that will come to work for a guide dog owner. The aim of this study was to see to which frequency and in what way guide dogs for the visually impaired are disturbed when they are on duty out in public places. In order to collect data a survey was conducted, where 18 guide dog owners described one to two typical situations of disturbance from other dogs, which occurs when the guide dog are on duty. Nearly 90 percent of the guide dog owners reported that one or more disturbance had occurred, where lunges was the most common type of disturbance followed by active play and attack. The majority of the affected guide dogs in this study were males of the breed Labrador retriever. Several of the guide dogs got mental and/or physical injuries due to the disturbance and had to be taken out of duty temporarily. The attacks may have been based on a lack of communication between the dogs. The results are based on a limited sample, therefore they may not be representative of the situation for the entire Swedish guide dog population but it is possible to sense a problem. This study is the first of its kind to be carried out in Sweden and leaves room for further research.
50
Remus, Merissa Lynn. "Contribution of Nucleus Accumbens to Reward-Seeking Behaviors: Role of Dopamine-Mediated ERK Signaling." Research Showcase @ CMU, 2015. http://repository.cmu.edu/dissertations/470.
Full textAbstract:
Exposure to environmental cues that have been associated with rewards tend to increase behaviors that serve to procure the reward. The excitatory modulation that so-called conditioned cues exert over reward seeking depends on the nucleus accumbens (NAc). A critical molecular step within the NAc in this behavioral phenomenon is activation of extracellular signal-regulated kinase (ERK) in the NAc. The first set of experiments served to investigate the subregional pattern of ERK activation within the NAc during cue-potentiation of reward seeking and the contribution of different elements in the behavioral situation to the distribution of ERK signaling in the NAc of rats. We found that the occurrence of rewardseeking behavior did not affect ERK activation in either the core or the shell of the NAc. In contrast, presentation of the conditioned cue caused a significant increase in ERK activation in both subregions of the NAc. Different from the pattern evoked by the cue, presentation of the reward itself had no effect on ERK activation in the core but caused a pronounced increase in ERK activation in the shell. Taken together, these results demonstrate that ERK signaling in the NAc during cue-evoked reward seeking involves both the core and the shell and is driven by the conditioned cue irrespective of whether or not the situation permits engagement in reward-seeking behavior. Furthermore, the results show that the subregional distribution of ERK signaling in the NAc evoked by rewards differs from that evoked by cues that predict them. The second set of experiments served to determine the contribution of NAc dopamine type 1 (D1) versus type 2 (D2) receptors to cue-evoked NAc ERK activation, and to identify the phenotype of NAc cell in which cue-evoked ERK activation occurs. We found that NAc D1 receptor antagonism markedly blunted the cue-evoked increase in ERK signaling in both the core and the shell, whereas NAc D2 receptor antagonism had no effect on ERK signaling. In addition, we found that every cell in the NAc of rats exhibiting cuepotentiated reward seeking that stained immunopositive for active ERK also stained for prodynorphin, a neuropeptide that in the NAc is expressed selectively by D1 receptorcontaining medium spiny neurons. These results demonstrate that conditioned cue-evoked ERK activation is mediated by D1 receptors and takes place in D1 receptor expressing NAc projection cells. Taken together with findings that D1 receptor antagonism abrogates the ability of conditioned cues to potentiate reward seeking, the results point to a molecular mechanism through which dopamine mediates enhanced reward seeking in the presence of reward-predictive cues. Furthermore, the results suggest that inputs to and projection targets of D1 receptor-expressing NAc output cells are candidate elements of the neural circuit underlying cue-potentiation of reward seeking. Collectively, the findings may lead to the development of targeted interventions for the treatment of conditions characterized by maladaptive reward seeking, such as drug addiction and obesity.