Academic literature on the topic 'Bulbectomie'

Introduction: Endocannabinoid system is involved in neuropsychiatric disorders such as major depression. The bilaterally olfactory bulbectomized rat is widely used as an animal model of depression. The removal of the olfactory bulbs produces behavioural, physiological, and neurochemical alterations resembling clinical depression. There is increasing evidence that highlights the important role of cannabinoid signalling in depression and nociception. Aim: To investigate the effect of CB1 receptor agonist HU 210 and CB1 receptor antagonist SR 141716A administered icv subchronically (for 7 days) on nociception of rats with model of depression - bilateral olfactory bulbectomy (OBX). Material and methods: Experimental model of depression - bilateral olfactory bulbectomy (OBX). Bilaterally olfactory bulbectomized rats were used as an experimental model of depression. HU 210 (5 µg) or SR 141716A (3 µg) were infused icv for 7 consecutive days, starting 15 days after the olfactory bulbectomy. Nociception was examined by applying paw pressure test (analgesy-meter) evaluating the rat pain threshold. On day 7, five minutes after the last microinjection, the rats were tested in an analgesy-meter and their mechanically evoked pain responses were measured in arbitrary units (AU). Results: Microinjections of HU 210 (5 µg) significantly decreased the pain threshold in olfactory bulbectomized rats, while SR 141716A (3 µg) exerted antinociceptive effect by increasing the pain threshold. Conclusions: Data point to an involvement of CB1 receptors in depression-like behaviour and nociception in olfactory bulbectomized rats and support the data for the association between depressive disorder and pain pathways.

Background Olfactory receptor neurons (ORNs) undergo apoptosis at a baseline rate even in the absence of obvious disease. Although the precise triggers of the apoptotic cascade are unclear, ORNs are exposed directly to the external environment, making them susceptible to injury. As an adaptive mechanism, mammals have the ability to replace lost ORNs throughout adult life from neuronal precursors within the olfactory epithelium (OE). In humans, this process fails with age as the surface area of the OE and the number of ORNs decline, coupled with a loss of clinical olfactory function. The question addressed in this study is whether this age-related failure of olfactory sensation is a result of a decrease in neuronal proliferation or an increase in ORN cell death. Methods To begin to address this question the ribonuclease protection assay was used to assess expression of apoptosisrelated genes in rat OE as a function of age. Second, the terminal deoxynucleotide transferase end labeling assay was used to assess the percentage of ORNs undergoing apoptosis (apoptotic index) in three groups of animals: young (12 weeks), old (32 months), and bulbectomized rats. Bulbectomy is a standard model for ORN injury associated with a massive increase in ORN apoptosis and serves as a positive control. Results Ribonuclease protection assay data indicate an age-related increase in Bax, Bcl-xL, and procaspase-3 messenger RNA expression in aged compared with young rats. A similar but more pronounced increase in expression of these apoptotic-related genes is seen after bulbectomy. The terminal deoxynucleotide transferase end labeling assay also showed a statistically significant increase in the apoptotic index with both age and bulbectomy. Conclusion Taken together, the current results indicate that aging and injury induce parallel changes in OE. Furthermore, these findings support the hypothesis that age-related olfactory dysfunction is, at least in part, related to an increase in ORN cell death.

Aims and objectivesThe aim of study was to evaluate the pharmacotherapeutic efficacy of NDGA in experimental paradigm of depression i.e. olfactory bulbectomy (OB) specifically targeting kynurenine pathway.Materials and methodDepression like behaviours was induced in OB mice and evaluated by assessment of various behavioural (olfactory deficit test, forced swim test, splash test, open field test, sucrose preference test), biochemical (catalase, reduced glutathione, SOD, nitrite, MAO-A, MDA, corticosterone), inflammatory cytokines (TNF- α, IL-1β, IL-6, IFN-γ) levels and alterations in delta sleep was recorded using EEG. Kynurenine pathway metabolites were determined in plasma and brain using HPLC method. After 14 days post-surgery, olfactory bulbectomized (OBX) mice were administered nordihydroguaiaretic acid (5 mg/kg, 10 mg/kg and 25 mg/kg) daily i.p.ResultsWe have developed a new HPLC method for simultaneous estimation of monoamines and kynurenine pathway metabolites in plasma and brain samples of mice. Chronic treatment with nordihydroguaiaretic acid significantly restored all behavioural, biochemical and neurochemical alterations in OBX mice and increase in quinolinic acid and decrease in kynurenic acid point out the neurodegeneration hypothesis of depression.ConclusionNordihydroguaiaretic acid showed potent neuropharmacotherapeutic effect in OBX mice by virtue of its strong anti-oxidant, anti-inflammatory, anti-stress and by restoring quinolinic acid levels.

AbstractObjective:This study aimed to investigate the function of tissue plasminogen activator in the olfactory epithelium of mice following neural injury.Method:Transmission electron microscopy was used to study the changes in the morphology of the olfactory epithelium 1–7 days after surgical ablation of the olfactory bulb (bulbectomy).Results:Prior to bulbectomy, a uniformly fine material was observed within some regions of the olfactory epithelium of mice deficient in tissue plasminogen activator. At 2–3 days after bulbectomy, there were degenerative changes in the olfactory epithelium. At 5–7 days after bulbectomy, we noted drastic differences in olfactory epithelium morphology between mice deficient in tissue plasminogen activator and wild-type mice (comparisons were made using findings from a previous study). The microvilli seemed to be normal and olfactory vesicles and receptor neuron dendrites were largely intact in the olfactory epithelium of mice deficient in tissue plasminogen activator.Conclusion:The tissue plasminogen activator plasmin system may inhibit the regeneration of the olfactory epithelium in the early stages following neural injury.

Background: The combination of buprenorphine, a partial mu-opioid receptor agonist and a functional kappa-opioid receptor antagonist, with samidorphan, a functional mu-opioid receptor antagonist, is being developed as an adjunct therapy for major depressive disorder, in order to harness the mood-enhancing effects of opioids without unwanted side-effects such as a risk of addiction. Acute and subacute administration of the combination of buprenorphine and samidorphan is effective in reducing forced swim immobility in the Wistar-Kyoto rat, but the chronic effects have not been examined. Aims and methods: The purpose of this study was to assess if chronic (14-day) administration of buprenorphine (0.1 mg/kg, subcutaneous) alone or in combination with samidorphan (0.3 mg/kg, subcutaneous) maintains antidepressant-like activity in the olfactory bulbectomised rat model and the Wistar-Kyoto rat, two models that exhibit ongoing behavioural deficits in tests commonly used to study effects of antidepressants. Results: Olfactory bulbectomised-induced hyperactivity was attenuated by chronic administration of buprenorphine alone and in combination with samidorphan, to that of sham control activity levels. Neither buprenorphine nor samidorphan altered stress-associated defecation in sham or olfactory bulbectomised rats in the open field. In Wistar-Kyoto rats, buprenorphine alone significantly reduced forced swim immobility and increased locomotor activity three hours post-final dosing. Buprenorphine plus samidorphan significantly reduced forced swim immobility without changing locomotor activity at this time point. Buprenorphine alone also significantly reduced forced swim immobility 24 h post-final dosing. Conclusion: Chronic treatment of buprenorphine alone or buprenorphine plus samidorphan is effective in reversing behavioural deficits in distinct non-clinical paradigms. These non-clinical results complement the antidepressant effect of this combination observed in clinical studies.

ABSTRACT The body weight and sexual activity of the male lesser mouse lemur, a prosimian primate, undergo cyclic changes that are photoperiod-dependent. Exposure to long daylength (LD; 14 h light/day) led to sustained sexual activity, fully developed testes and high plasma testosterone concentrations (228 ±25 nmol/l, n = 10). After 14 weeks under LD, a marked decrease in testosterone levels occurred. Gonadal regression was completed within 20 weeks under LD without concomitant changes in body weight. Exposure to short daylength (SD; 8 h light/day) reinforced the sexual quiescence and was associated with a high ponderal gain (from 60 to 110 g). However, independent of the date of gonadal arrest, the sexual activity of males spontaneously resumed at a fixed time after exposure to SD. The testes developed, testosterone concentrations increased to 155 nmol/l and the body weight decreased (from 110 to 80 g) within 20 weeks under SD exposure. The timing for refractoriness appeared very similar under inhibitory and stimulatory photoperiods. This is consistent with the hypothesis that the perception of a critical daylength is used to regulate the timing of the following sexual phase through a mechanism involving photorefractoriness. Contrary to cricetid rodents, a direct response to photoperiodic signals for both body weight and sexual activity were not prevented by olfactory bulb removal in male mouse lemurs. In bulbectomized males (n = 12), sexual activity was stimulated by LD and inhibited by SD. Their plasma testosterone levels, however, significantly differed from those of controls in both photoperiods. Likewise, ponderal cycles remained intact but the fattening phase was delayed and reduced. Finally, whereas the sexual recrudescence of bulbectomized males occurred under SD with a delay of only 2–4 weeks, spontaneous testicular regression under exposure to LD did not appear in our experimental photoperiodic conditions. Journal of Endocrinology (1993) 137, 511–518

O sistema olfatório desempenha um papel relevante na exploração do ambiente e no reconhecimento social e sexual de mamíferos. Por meio deste sistema os animais podem reconhecer, detectar e discriminar uma grande quantidade de odorantes de estruturas químicas variadas, sinais químicos no ambiente essenciais para a sobrevivência e os ferormônios, que desencadeiam comportamentos sociais e reprodutivos. Algumas doenças e certos tipos de injúrias fisiológicas podem provocar a morte destas células, o que pode levar a perda da sensibilidade olfatória, embora já se saiba que este epitélio apresenta grupos de neurônios capazes de regeneração. A partir deste contexto, a terapia celular acaba sendo uma alternativa para o tratamento de patologias as quais acometem o sistema olfatório, como por exemplo, a anosmia que pode causar problemas graves, desde acidentes com gás ou comida estragada até depressão e distúrbios alimentares, causadas pela perda do paladar. Objetivou-se com este trabalho avaliar a recuperação da função olfatória de ratos anósmicos, bulbectomizados e submetidos a terapia celular com células-tronco provenientes do epitélio olfatório de ratos wistar. Para tanto foram utilizados 21 ratos machos Wistar de sessenta dias de idade, onde três foram utilizados para obtenção das células tronco do epitélio olfatório, dois para o controle cirúrgico, e restante foram divididos em 4 grupos: GI, GII, GIII e GIV os quais foram transplantados após 3, 7, 14 e 21 dias após a bulbectomia, respectivamente. A técnica cirúrgica foi realizada com incisão de pele, tecido subcutâneo e periósteo, seguida de abertura em janela de formato ovalado e remoção dos bulbos olfatórios mediante aspiração. Para a comprovação da anosmia após a cirurgia, os ratos foram submetidos ao teste comportamental do \"odor de gato\", e os do grupo controle após o período experimental foram sacrificados e a área encefálica da lesão causada pela cirurgia foi coletada onde foram realizadas análises histopatológicas. Os animais do GI, GII, GIII e GIV após 3, 7, 14 e 21 dias após bulbectomia foram anestesiados e receberam células tronco (1x106) do EOR no mesmo local da realização da bulbectomia, e posteriormente foram submetidos ao teste comportamental do \"odor de gato\". Transcorrido o período experimental, foram eutanasiados e os fragmentos de encéfalo foram coletados para análise histopatológica e imunohistoquímica. Os resultados evidenciam que realização da intervenção cirúrgica demonstrou remoção parcial do BO, com destruição da conexão nervosa entre os bulbos olfatórios e o epitélio olfatório. Ainda, a partir do teste comportamental do \"odor de gato\", e pela análise histopatológica das lesões causadas pela cirurgia, que evidenciou extensa área de necrose, com presença de hemossiderina e astrogliose reativa, constatou-se que a técnica empregada para promoção da bulbectomia foi eficaz para promoção da anosmia. A partir da análise comportamental, dos animais submetidos a terapia celular, os animais do GII e GIII apresentaram modificações no comportamento olfativo, com comportamento olfativo positivo ao \"odor do gato\", aversão comportamento defensivo, enquanto 100% dos animais do GI e GIV não apresentaram nenhuma modificação no comportamento olfativo. As análises por imunohistoquímica evidenciaram marcação positiva para o GFP, o que indica a presença das células tronco transduzidas com eGFP nos locais das lesões e ainda a expressão positiva do GFAP que evidencia a presença de astrogliose reativa com presença de cicatriz glial nos locais das lesões.
The olfactory system plays an important role in the exploration of the environment and in social and sexual behavior in mammals. Disturbances of the olfactory system such as observed in anosmia has also been related to accidents caused by gas leak and intoxications by food poisoning, in addition to eating disorders due to relation of the olfactory system with the taste. Through the olfactory system, animals recognize, detect and discriminate a large amount of odorants in a variety of chemical products, including pheromones, as well as in the environment which may guarantee their survival. Some diseases and injuries cause death of cells from the olfactory system leading to decrease or loss of the smell sensitivity. It is known that the olfactory epithelium has cells capable of regenerating neurons. Therefore, the utilization of these cells in cell therapy represents an alternative for the treatment of the olfactory system disorders. The objective of this study was to evaluate the regenaration of olfactory function of bulbectomized rats that were subjected to cell therapy with cells isolated from the olfactory epithelium. Twenty one male Wistar rats, sixty days of age were included in this study. Three rats were used for isolation of the olfactory epithelium cells, two for the surgical control and the remaining were divided into 4 groups: GI, GII, GIII and GIV corresponding to groups where cells were transplanted after 3, 7, 14 and 21 days after bulbectomy, respectively. The surgical technique was performed with skin, subcutaneous and periosteum incisions, followed by craniectomy and the removal of olfactory bulbs upon aspiration. For proof of anosmia, the rats were subjected to behavioral testing know as \"cat odor\". The animals of the control group were sacrificed and brain, with the lesion area, collected and processed for histopathological analysis. The animals of the experimental groups (GI, GII, GIII and GIV) were anesthetized and received heterologous cells (1x106) from olfactory epithelium, thorugh the same venue of the bulbectomy. These animals subsequently underwent behavioral \"cat odor\" testing. After 3, 7, 14 and 21 days of the cell injection, the rats were euthanized and the animals brains were collected for histopathological and immunohistochemical analyses. The results show that the surgical procedure promoted partial removal of olfactory bulbs, with destruction of the neural connection between the olfactory bulb and the olfactory epithelium. The behavioral \"cat odor\" test and the histopathological exams of the lesions, which revealed a large area of necrosis with presence of hemosiderin and reactive astrogliosis, demonstrated that the bulbectomy technique used to promote anosmia was effective. The behavioral test showed that the animals from GII and GIII presented changes in olfactory sensitivity, with positive \"cat odor\" aversion and defensive reaction. This test did not show change in GI and GIV groups. Immunohistochemistry analysis was positive for GFP, suggesting the presence of eGFP transduced cells at the sites of injury. In addition, the expression of GFAP positive cells demonstrated the presence of reactive astrogliosis with glial scar at the sites of injury.

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A doença de Parkinson (DP) é a segunda doença neurodegenerativa mais prevalente na população idosa, tendo como principal característica neuropatológica a depleção de dopamina (DA) estriatal, condição esta, que conduz ao aparecimento dos sintomas motores da doença. Além de sintomas motores, os pacientes acometidos com essa doença apresentam ainda sintomas não motores e neuropsiquiátricos onde destaca-se a depressão. Atualmente, nenhuma das drogas utilizadas é totalmente eficaz para a DP, nesse contexto, terapias promissoras ainda precisam ser exploradas. Alguns estudos demonstraram que o consumo de flavonoides podem diminuir a incidência e os sintomas de doenças neurodegenerativas e de transtornos depressivos. Nosso estudo anterior já constatou que o flavonoide hesperidina (4'-methoxy-7-O-rutinosyl-3',5-dihydroxyflavanone), intervém na DP e no comportamento tipo depressivo via estresse oxidativo, em um modelo induzido por 6-hidroxidopamina (6-OHDA) em camundongos. Baseando-se nas evidências, se torna interessante investigar o efeito da hesperidina em outros parâmetros da DP no modelo da 6-OHDA, além de seu efeito antidepressivo no modelo da bulbectomia olfatória (BO). Para avaliar a DP, a hesperidina ou o veículo (50 mg/kg) foram administrados via oral (gavagem) durante 28 dias. Após este período, os camundongos foram submetidos a testes comportamentais. Para avaliar a depressão no modelo OB, a hesperidina ou o veículo (50 mg/kg) foram administrados via oral (gavagem) durante 13 dias. Após este período, os camundongos foram submetidos aos testes comportamentais e neuroquímicos. No modelo induzido pela 6-OHDA, o tratamento com a hesperidina protegeu contra a inibição das enzimas mitocondriais dos complexos I, II, IV e V, da enzima Na+/K+ ATPase, diminuição do potencial de membrana mitocondrial, e aumento das atividades das caspases 3 e 9 e níveis de marcadores de inflamação. Além disso, a administração do flavonoide culminou na restauração dos níveis de fatores neurotroficos, assim como dos neurônios positivos para tirosina hidroxilase (TH), e níveis de DA e seus metabolitos no estriado. O tratamento com hesperidina também atenuou as alterações comportamentais de rotação, ansiedade, anedonia, memória e nos danos olfatórios induzidos pela 6-OHDA. No modelo de depressão induzido pela OB, o tratamento oral com hesperidina foi efetivo em reverter o declínio dos fatores neurotróficos, o aumento das citocinas pro-inflamatórias e da atividade da enzima acetilcolinesterase (AchE) no hipocampo, bem como o aumento da atividade locomotora, os prejuízos na memória, o comportamento tipo depressivo e a anedonia decorrentes da remoção dos bulbos. No modelo de DP induzido pela 6-OHDA pode-se propor que a hesperidina atua na restauração dos neurônios dopaminérgicos através do restabelecimento dos fatores neurotróficos, controle das citocinas, e modulação da atividade mitocondrial e apoptótica no estriado, o que reflete na recuperação dos prejuízos comportamentais. No modelo da depressão, indica-se que a reparação hipocampal sobre os fatores neurotróficos e marcadores inflamatórios são responsáveis pelo reestabelecimento comportamental no tratamento com hesperidina. Estes resultados certificam o efeito potencial da hesperidina no tratamento da DP e dos distúrbios depressivos, indicando que esse flavonoide pode atuar como terapia multialvo, associando DP e os transtornos mentais. Isso se deve à 4 regulação de fatores neurotróficos, inflamatórios e apoptóticos, atividades enzimáticas (AchE e Na+/K+ ATPase), disfunção mitocondrial e recuperação neuronal dopaminérgica.
Parkinson's disease (PD) is the second most prevalent neurodegenerative disease in the elderly population. Its main neuropathological characteristic is the striatal dopamine (DA) depletion, which leads to the appearance of the motor symptoms of the disease. In addition to motor symptoms, the patients with this disease also present non-motor and neuropsychiatric symptoms where depression stands out. Currently, none of the drugs used is fully effective for PD, in this context, promising therapies still need to be explored. Some studies have shown that consumption of flavonoids may decrease the incidence and symptoms of neurodegenerative diseases and depressive disorders. Our previous study has found that the flavonoid hesperidin (4'-methoxy-7-O-rutinosyl-3 ', 5-dihydroxyflavanone) plays a role in PD and in the depressive behavior via oxidative stress in mice induced by 6-hydroxydopamine (6 -OHDA). Based on the evidence, is interesting to investigate the effect of hesperidin in other parameters of PD in the 6-OHDA model, besides the its antidepressant effect in olfactory bulbulometric (BO) model. To evaluate the PD, hesperidin or vehicle (50 mg / kg) were administered orally (gavage) for 28 days. After this period, the mice were submitted to behavioral tests. To assess depression in the OB model, hesperidin or vehicle (50 mg / kg) were administered orally (gavage) for 13 days. After this period, the mice were submitted to behavioral and neurochemical tests. In the 6-OHDA-induced model, treatment with hesperidin protected against inhibition of mitochondrial enzymes of complexes I, II, IV and V, Na + / K + ATPase enzyme, against the decrease in mitochondrial membrane potential, and against the increase of caspases 3 and 9 activities and inflammatory markers levels. In addition, flavonoid administration culminated in restoration of neurotrophic factors levels, as well as tyrosine hydroxylase (TH) positive neurons, DA and its metabolites levels in the striatum. The treatment with hesperidin also attenuated the behavioral changes of rotation, anxiety, anhedonia, memory and olfactory damage induced by 6-OHDA. In addition, in depression model OB-induced, oral hesperidin treatment was effective in reversing the decline of neurotrophic factors, increase of proinflammatory cytokines levels and acetylcholinesterase (AchE) activity in the hippocampus, as well as increase of locomotor activity, memory impairment, depressive behavior and anhedonia due to removal of bulbs. In DP model induced by 6-OHDA it can be proposed that hesperidin acts in the restoration of dopaminergic neurons through the reestablishment of neurotrophic factors, cytokine control, and modulation of mitochondrial and apoptotic activity in striatum, which reflects in the recovery of damages behavioral. In depression model, it is indicated that hippocampal repair on neurotrophic factors and inflammatory markers are responsible for behavioral reestablishment by hesperidin treatment. These results confirm the potential effect of hesperidin in the treatment of PD and depressive disorders, indicating that this flavonoid can act as a multi-target therapy, associating PD and mental disorders. This is due to the regulation of neurotrophic, inflammatory and apoptotic factors, enzymatic activities (AchE and Na+/K+ ATPase), mitochondrial dysfunction and dopaminergic neuronal recovery.

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A depressao e uma doenca altamente incapacitante e que tem acometido um percentual crescente da populacao mundial. Ainda que varios antidepressivos estejam comercialmente disponiveis ha decadas, os efeitos colaterais destas drogas, aliados ao fato de que nem todos os pacientes respondem satisfatoriamente ao tratamento, levam a uma busca continua por novas alternativas para o tratamento ou complementacao do tratamento da depressao. Assim, expande-se cada vez mais o numero de estudos que avaliam compostos candidatos a antidepressivos. Neste contexto e que o efeito tipo-antidepressivo da crisina, um flavonoide natural abundante no maracuja do mato (Passiflora coerulea), em camundongos submetidos ao estresse cronico imprevisivel (UCS) foi demonstrado anteriormente por nosso grupo. No entanto, os fatores neuroquimicos associados a este efeito carecem de maiores investigacoes. Deste modo, o objetivo deste estudo foi avaliar os fatores neuroquimicos associados ao efeito tipo-antidepressivo do flavonoide crisina em dois modelos animais de depressao, o modelo do UCS e o modelo da bulbectomia olfatoria (OB), ambos em camundongos. No modelo do UCS foram avaliados o cortex pre-frontal (PFC) e o hipocampo (HP), enquanto no modelo da OB foi avaliado o HP. O UCS e a OB induziram um comportamento tipo-depressivo, caracterizado pela diminuicao no tempo de lambida no teste de borrifagem de sacarose e pelo aumento no tempo de imobilidade no teste de suspensao de cauda ou no teste de nado forcado. Ainda, a OB ocasionou alteracoes no teste de campo aberto, decorrentes da hiperatividade caracteristicamente induzida por este modelo. O tratamento oral com crisina (5 ou 20 mg/kg, durante 28 dias no modelo do UCS, e por 14 dias no modelo da OB), de forma semelhante a fluoxetina (10 mg/kg, controle positivo), culminou na prevencao destas alteracoes, confirmando a acao tipo-antidepressiva da crisina nos parametros comportamentais avaliados. O UCS ocasionou o aumento nos niveis plasmaticos do hormonio liberador de corticotrofina, do hormonio adrenocorticotrofico, e a atividade das caspases 3 e 9 nas estruturas cerebrais avaliadas, enquanto a OB ocasionou a reducao dos niveis hipocampais do fator neurotrofico derivado do encefalo. O UCS e a OB resultaram no aumento dos niveis de citocinas proinflamatorias nas estruturas cerebrais avaliadas, como fator de necrose tumoral-α, interferon- γ, interleucina-1β, interleucina-6, alem do aumento dos niveis de quinurenina. O UCS e a OB tambem induziram a diminuicao dos niveis de 5-hidroxitriptamina (5-HT) e o aumento da 11 atividade da enzima indoleamina-2,3-dioxigenase. O tratamento com crisina, de forma semelhante a fluoxetina, promoveu a atenuacao de todas estas alteracoes ocasionadas pelo UCS ou pela OB. Em suma, os resultados deste estudo vem a corroborar com a hipotese de que o flavonoide crisina e um alvo potencial no estudo de novas alternativas para o tratamento ou para a complementacao do tratamento da depressao. Adicionalmente, este trabalho indica a associacao das citocinas pro-inflamatorias, da via da quinurenina, do metabolismo da 5-HT, das neurotrofinas e da atividade das caspases na acao tipo-antidepressiva exercida pela crisina em camundongos expostos ao UCS ou a OB. Finalmente, o presente trabalho expoe o maracuja do mato como um importante alvo para o estudo dos produtos naturais no combate a depressao, mostrando a fundamentalidade da investigacao da funcionalidade e constituicao bioativa desta e outras plantas do bioma pampa.
Depression is a highly incapacitating disease that has affected a crescent percentage of the world population. Although various antidepressants have been commercially available for decades, the side effects of these drugs, together with the fact that not all patients respond satisfactorily to treatment, lead to continuous search for new alternatives for the treatment or supplementary treatment of depression. Thus, the number of studies evaluating compounds candidate to antidepressants expands increasingly. In this context, the antidepressant-like effect of chrysin, a natural flavonoid abundant in passion fruit bush (Passiflora coerulea), in mice subjected to unpredictable chronic stress (UCS) has been previously demonstrated by our group. However, neurochemical factors associated with this effect require further investigations. Thus, the objective of this study was to evaluate the neurochemical factors associated with the antidepressant-like effect of chrysin in two animal models of depression, the model of UCS and the model of olfactory bulbectomy (OB), both in mice. In the UCS model the prefrontal cortex (PFC) and the hippocampus (HP) were evaluated, in the OB model the HP was evaluated. The UCS and OB induced a depressive-like behavior, characterized by the decrease in the total time of grooming in the splash test and by increase on immobility time in the tail suspension test or forced swimming test. Still, OB induced changes in open field test, resulting from the hyperactivity characteristically induced by this model. The oral treatment with chrysin (5 or 20 mg/kg for 28 days in the UCS model and for 14 days in OB model), similarly to fluoxetine (10 mg/kg, positive control) resulted in the prevention of these changes, confirming the antidepressant-like action of chrysin in the behavioral parameters evaluated. The UCS led to an increase in plasma levels of corticotropin-releasing hormone, adrenocorticotropic hormone and activity of caspases 3 and 9 in the brain structures evaluated, while the OB caused a reduction of hippocampal levels of brain-derived neurotrophic factor. The UCS and OB resulted in increase of proinflammatory cytokines levels in the brain structures evaluated, such as tumor necrosis factor-α, interferon- γ, interleukin-1β, interleukin-6, and increase kynurenine levels. UCS and OB also induced the decrease in 5-hydroxytryptamine (5-HT) levels and the increase of the activity of indoleamine-2,3-dioxygenase enzyme. Treatment with chrysin, similarly to fluoxetine, 13 promoted the attenuation of all these changes caused by UCS or OB. In summary, results of this study come to corroborate the hyphotesis that the flavonoid chrysin is a potential target in the study of new alternatives for the treatment or complement treatment of depression. Additionally, this study indicates the association of pro-inflammatory cytokines, of kynurenine pathway, of 5-HT metabolism, of neurotrophins and of caspases activities in the antidepressant-like action exerted by chrysin in mice exposed to UCS or OB. Finally, this paper exposes the passion bush as an important target for the study of natural products to combat depression, showing the importance of research of functionality and bioactive constitution of this and other plants of the pampa biome.

Os Transtornos psiquiátricos acompanham a história da humanidade. Classificados em categorias distintas podemos observar que dentre todas as patologias que constituem os transtornos mentais e de comportamento, as doenças mais prevalentes são as doenças de Ansiedade e de Transtorno Depressivo Maior (TDM). Mesmo com muitos avanços nas neurociências, assim como na terapêutica (psicofarmacologia), ainda hoje a fisiopatologia e o desenvolvimento farmacológico são áreas que necessitam intenso estudo. Avanços recentes tem sugerido que drogas capazes de modular os sistemas glutamatérgico e purinérgico possuem potencial efeito neuromodulador, sendo promissores candidatos para o desenvolvimento de novas drogas com ação ansiolítica e/ou antidepressiva. Dessa maneira, o objetivo desta tese foi investigar o potencial efeito ansiolítico da guanosina (GUO) em modelos animais preditivos para o estudo da potencial atividade ansiolítica de novos compostos, assim como seu potencial efeito antidepressivo no modelo animal de depressão da Bulbectomia Olfatória Bilateral (OBX). Inicialmente, nossos resultados demonstram que a administração de GUO foi capaz de produzir um consistente efeito ansiolítico modulando os níveis de adenosina (ADO) e glutamato cerebral. Ainda, pela primeira vez, foi observado que a GUO per se promoveu uma diminuição da liberação de glutamato em preparações de sinaptosomas de hipocampo, um efeito dependente da ativação dos receptores A1 de ADO. Após a caracterização do potencial efeito ansiolítico da GUO, nosso objetivo foi avaliar o potencial efeito antidepressivo da GUO em um modelo animal com validade de face e de constructo, como o modelo da OBX. Contudo, após revisão da literatura em estudos que utilizaram o modelo da OBX, observou-se a necessidade de uma investigação a longo prazo, das principais alterações comportamentais e neuroquímicas induzidas pela OBX. Nossos resultados, mostram pela primeira vez, que camundongos submetidos a OBX apresentaram simultaneamente alterações comportamentais e neuroquímicas transitórias e de longa duração. Ademais, as evidências indicam que o hipocampo possui alta susceptibilidade aos danos induzidos pela OBX, visto que uma sinaptotoxicidade transitória, acompanhada de um duradouro desequilíbrio redox e aumento da resposta inflamatória foram observados. Por fim, o tratamento crônico com GUO foi capaz de reverter a maioria das alterações identificadas previamente como duradouras nos parâmetros comportamentais e neuroquímicos no modelo da OBX. Considerando os resultados neuroquímicos obtidos pelos diferentes protocolos de tratamento realizados neste estudo, novas hipóteses de mecanismos de ação exercidos pela GUO foram apresentadas, e mecanismos já estabelecidos foram reproduzidos. Por fim, de uma maneira geral os dados apresentados nesta tese reforçam a hipótese do envolvimento do sistema purinérgico nos transtornos psiquiátricos, e sugerem que a GUO apresenta uma potencial ação terapêutica para o tratamento destas doenças, abrindo assim novas perspectivas para elucidação dos mecanismos envolvidos na fisiopatologia da ansiedade e TDM.
Psychiatric disorder had accompanied the course of human history. Mental and behavioral disorders are classified in different categories and among all different psychiatric disorders; anxiety and major depressive disorder (MDD) are the most prevalents. Despite the substantial advances in our knowledge on the neurobiological bases of both anxiety and MDD, as well as in the therapeutic area (psychopharmacology), even today, the pathophysiology of these disorders as well as pharmacological development are still under investigation. Recent advances have suggested that drugs able to modulate glutamatergic and purinergic systems present a potential neuromodulatory effect, and are promising candidates for the development of new drugs with both anxiolytic and antidepressant effects. Thus, the aim of this work was to investigate the potential guanosine (GUO) anxiolytic-like effects in predictive animal models largely used to elucidate anxiolytic properties of new compounds, as well as investigate the potential GUO antidepressant effect in Olfactory Bulbectomy (OBX) model of depression. Initially, our results demonstrate that acute GUO administration was able to induce a consistent anxiolytic-like effect, by modulating the adenosine and glutamate cerebrospinal levels. Here, for the first time, it was observed that GUO per se was able to decrease the glutamate release in hippocampal synaptosome. After characterizing the potential anxiolytic-like effect promoted by GUO, our second goal was to evaluate the potential GUO antidepressant-like effect in an animal model with recognized face and construct validity as the OBX model of depression. However, given the lack of studies in the literature considering the time course of the behavioral and neurochemical changes after the depressive-like behavior onset induced by OBX we firstly characterize some important features regarding the OBX model. Collectively, mice submitted to the OBX model of depression and followed up to 8 weeks simultaneously presented transient and long-lasting deleterious effects in behavioral and neurochemical parameters. The evidences pointed that hippocampus was the most affected brain structure, since a transient hippocampal-related synaptotoxicity, accompanied by a long-lasting hippocampal imbalance in redox and inflammatory homeostasis were observed. Additionally, the neurochemical effects seem to strengthen our behavioral findings. Finally, chronic GUO treatment, similarly to the classical tricyclic antidepressant imipramine, was able to improve the long-term behavioral phenotype impairment induced by OBX, specifically improving behavioral performances that require cognitive functions, accompanied by reversion of hippocampal redox imbalance parameters, as well as in peripheral and central anti-inflammatory IL-10 release. Thus, in present study, the pre-clinical evaluation of GUO as a potential drug for treatment of the most prevalent psychiatric disorders (anxiety and MDD) presented promising results. Furthermore, additional GUO mechanisms of action were evidenced and new perspectives were established. Thus, the data presented in this thesis support the hypothesis of the involvement of the purinergic system in mood disorders, and suggest that GUO has a potential therapeutic activity for the treatment of psychiatric disorders.

La dépression est une maladie chronique, récurrente et potentiellement mortelle qui affecte plus de 20 % de la population à travers le monde. Les mécanismes sous-jacents de la dépression demeurent incompris et la pharmacothérapie actuelle, largement basée sur l’hypothèse monoaminergique, fait preuve d’une efficacité sous optimale et d’une latence thérapeutique élevée. Par conséquent, la recherche est amenée à élaborer de nouveaux traitements pharmacologiques. Pour détecter leur action, il est avant tout nécessaire de développer des outils expérimentaux adéquats. Dans cette optique, notre but a été de mesurer l’anhédonie, un symptôme cardinal de la dépression, chez le rat de laboratoire. L’anhédonie a été définie comme une réduction de la récompense et a été mesurée avec le test de consommation de sucrose et la technique d’autostimulation intracérébrale. En vue d’induire l’anhédonie, nous avons effectué une bulbectomie olfactive, une procédure qui entraîne divers changements biochimiques, cellulaires et comportementaux similaires à ceux de l’état dépressif et qui peuvent être renversés par un traitement antidépresseur chronique. Nos résultats montrent que la bulbectomie olfactive produit également l’anhédonie, reflétée par une réduction durable de la consommation de sucrose et par une réduction de l’efficacité de l’amphétamine dans le test d’autostimulation intracérébrale. Ces effets ont été présents jusqu’à trois à quatre semaines suivant la chirurgie. La bulbectomie olfactive a aussi été associée à une augmentation de l’élément de réponse liant l’AMPc dans le striatum, un index moléculaire associé à l’anhédonie. Ces découvertes suggèrent que l’anhédonie peut être produite et étudiée de façon fiable dans le modèle de bulbectomie olfactive et que le circuit de récompense pourrait constituer une cible cohérente pour de nouvelles drogues en vue du traitement de la dépression.
Depression is a chronic, recurrent and potentially deadly disorder that affects over 20 % of the population worldwide. The mechanisms underlying depression are still not understood and current pharmacotherapy, based largely on monoaminergic hypotheses, is plagued by suboptimal efficacy and delayed therapeutic latency. This has lead to a search for novel pharmacological treatments. To achieve this, it is first necessary to develop adequate experimental tools. With this in mind, we aimed to measure anhedonia, a cardinal symptom of depression, in laboratory rats. We defined anhedonia as a reduction in reward, and measured it with the sucrose intake test and in the intracranial self-stimulation paradigm. In order to induce anhedonia, we surgically removed the olfactory bulbs, a procedure that results in a host of behavioral, cellular and biochemical changes that are qualitatively similar to those observed in clinical depression. These changes are long-lasting and reversed by chronic antidepressant treatment, validating olfactory bulbectomy as an animal model of depression. Our results show that olfactory bulbectomy also produces anhedonia, reflected by a stable and long-lasting reduction in sucrose intake as well as a reduction in the rewarding effectiveness of amphetamine in the self-stimulation paradigm. These effects were present even after three to four weeks post-surgery. Olfactory bulbectomy was also associated with increased striatal cAMP response element binding, a molecular index associated with depressive-like behaviour. These findings suggest that anhedonia can be reliably produced and studied within the olfactory bulbectomy model and that reward circuitry may comprise a logical target for novel drugs to treat depression.

碩士
國立臺灣大學
生理學研究所
86
The research on muricidal behavior has proceeded to identify the variables that initiate or factors that affect this behavior. The main purpos e of the first study was to analyze monoamine changes in specific brain areas of olfactory bulbectomy (OBX) -induced muricidal rats with stable performance of muricidal behavior. Sixteen Wistar rats were subjected to olfactory bulbect omy. Then, 5 to 14 days after OBX, mice were introduced into rats'' home cages once a day in order to screen out the rats with muricidal behavior. About 56% of rats appeared muricidal behavior during this testing period. However, not e very rat that had displayed such behavior for the first time kept killing the mouse successfully in the following testing procedure during this period. Aft er that testing period, these rats were continually given the mouse every 2 to 3 days. About 30 days after OBX, they showed a stable muricidal behavior with killing latency less than 5 min for several consecutive tests. Besides, the a ttacklatency and killing latency of these rats were statistically shorter when compared to those of rats that showed their first muricidal behavior within 1 4 days after OBX. The muricidal behavior became skillful 30 days after OBX. Af ter analyzing 7 of these rats with stable muricidal behavior and 7 non-muricid al ones, we found that most monoamine turnover rates 30 days after OBX were no t different from killers to non-killers in their lateral hypothalamus (LH), ve ntromedial hypothalamus (VMH) and medial amygdala (MeAMY) except that 5-hydrox ytryptophan turnover rate was increased in VMH of killers. In the aspect of mo noamine content in these brain areas, only noradrenaline (NA) content in MeAMY was significantly increased in killers 30 days after OBX. When comparing our present results with others, we suppose that alteration of NA turnover rate in LH, VMH and MeAMY may have something to do with the appearance of muricidal b ehavior within 14 days after OBX. While the increase of 5-HT turnover rate in the VMH of killers 30 days after OBX may be related to the changes of eating h abit during the stabilization of muricidal behavior. Further studies were need ed in order to reveal more detailed mechanisms regarding the OBX-induced muric idal behavior in rats. The purpose of the second study was to modify the metho d used to assess the muricidal behavior induced by ablation of both olfactory bulbs in rats. Five days after olfactory bulbectomy, each rat was tested for t he performance of muricidal behavior by using mouse every other day. If the ra t showed muricidal behavior with killing latency shorter than 5 min for 3 cons ecutive testing procedures, it was used for the following incisor-cutting (IC) experiment. All muricidal rats were assigned to one of the two groups: inciso rs of rats either were cut off under ether anesthesia (group A) or kept intact as controls (group B). The MK behavior was observed between 2 pm and 5 pm for 4 days. One day after the last observation, rats in group A and B were treate d vice versa and the same exqerimental procedures were repeated. Following beh avioral parameters were recorded: killing latency, attack latency (AL), first attack sites (FAS), attack number (AN), attack duration (AD) and inter-attack interval. In experiment, IC did not affect MK behavior in AL, FAS and mean AD in 20 min whereas significant increases in total AD and AN were seen. About 23 % of rats did not kill the mouse 28 hr following IC. Killer rats spent about 1/3 of time in attacking the mouse 28 hr after IC. The total AD and AN decreas ed 52 hr after IC because the muricidal behavior of some rats were recovering. Since IC may prolong the total AD without influencing the basic muricidal beh avior patterns in killer rats, these results suggest that killer rats with IC may be a suitable and better model for microdialysis or drug treatment experim ent in research of muricidal behavior. It has been reported that both DMI and MK-801 inhibit olfactory bulbectomy- induced muricidal behavior in rats by dec reasing the killing percentage. In the third study, the incisor cutting (IC) m ethod described in Experiment II was used to distinguish the different effects of DMI and MK-801 on the olfactory bulbectomy-induced muricidal behavior in r ats. Twenty-eight hrs after IC, rats were divided into five groups and were su bjected to following treatments: saline (control group, n = 10), DMI 10 mg / k g (n = 7)、DMI 20 mg / kg (group A, n = 6)、DMI 20 mg / kg (group B, n = 8) an d MK-801 0.15 mg / kg (n = 7), respectively. All drugs were given through the I.P. injection and the observational period was 10 min for each rat. Except th at rats in DMI 20 mg group A and some in control group (n = 3) were observed f or the behavioral changes 30 min after the treatment, others were studied 1 hr after the administration of drugs. The attack latency in rats of all DMI-trea ted groups was significantly longer than that of control group. In contrast, r ats treated by MK-801 were unaffected in attack latency. After the injection o f DMI 10 mg, the attack numbers of rats was not statistically different from t hat of control group. A decrease in attack numbers was observed in both DMI 20 mg groups, while an increase was seen in MK-801-treated rats. Besides, DMI 10 mg and MK-801 treatment had no effect on the total attack duration and mean a ttack duration in rats. Only injection of DMI 20 mg in rats, in both group A a nd group B, significantly decreased total attack duration and mean attack dura tion. In addition, both groups of DMI 20 mg altered the temporal pattern of at tacking behavior with decreasing frequency of inter-attack interval less than 20 sec. Meanwhile, treatment of MK-801 increased the frequency of inter-attack interval less than 10 sec. But temporal pattern of attacking behavior was not changed by administration of DMI 10 mg. In all groups, most rats still used t o attack on the neck or chest of mice as their first attack sites. Only some r ats in both DMI 20 mg treated groups attacked on other non-lethal sites for th eir first attacks. Although both DMI and MK-801 treatments reduced killing per centage of muricidal rats, the incisor cutting animal model showed that these two drugs may affect the muricidal behavior through two different mechanisms.

碩士
國防醫學院
生物及解剖學研究所
106
The olfactory bulbectomized rat is one of the well-established animal models for the studies of depression. By surgically removing both olfactory bulbs of a rat, one would repeatedly induce behavioral and physiological changes in the animals that are qualitatively similar to those observed in patients of depression. However, knowledge regarding how the bulbectomy induce such effects is surprisingly very limited. To investigate acute effects of the bulbectomy on the olfactory and other central circuit, we performed the unilateral bulbectomy on 8-week-old Sprague-Dawley rats and collected the brains 24/48/72 hours after the surgical treatment. We used terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay to detect apoptotic cells along the olfactory pathway. Our results showed that the unilateral bulbectomy led to apoptosis in several regions over the olfactory pathway, including endopiriform nucleus and piriform cortex as soon as 24 hours after the surgical lesion. Beyond the olfactory pathway, to our surprise, we found very serious apoptosis in corpus callosum. In contrast to previous data, apoptosis in the piriform cortex peaks at 24 hours and gradually decreases until 72 hours after bulbectomy. However, the number of apoptotic cells in corpus callosum increases every 24 hours following the lesion. These findings suggest that traumatic injuries in the olfactory bulb could lead to acute and pervasive lesions that are beyond the olfactory pathway. Mechanisms underlying these effects may be more complicated than sensory deprivation.