Academic literature on the topic 'Biological Basis Of Behavior'

The hippocampus is a brain structure known to be important for learning and memory, more specifically for the acquisition of spatial information. Hebb (1940) suggested that storage of information in the brain may involve modifications in the strength of synaptic connections. One example of an artificially-induced synaptic alteration that may share common mechanisms with memory formation is long-term synaptic enhancement (LTE). Recently, behaviorally-induced changes in hippocampal synapses have been discovered to occur in conjunction with exploratory behavior. This type of change has been called short-term exploratory modulation (STEM). It was proposed that STEM could share common mechanisms with artificially-induced LTE and memory formation in the hippocampus. The primary goals in this dissertation were to determine the relationship between STEM and LTE, to identify the mechanisms controlling these changes, and to determine whether STEM was a critical component of memory storage, a memory modulator, or an epiphenomenon. Synaptic changes in the hippocampus were measured by recording perforant-path evoked field potentials in the fascia dentata from awake behaving rats during rest and exploration or under sodium pentobarbital anesthesia. In the first experiment, a positive correlation was found between learning in the Morris swim task and STEM in young and aged rats. Comparisons of LTE and STEM indicated that STEM did not reflect the same type of synaptic change observed in LTE, such that the two phenomena did not interact with each other. Furthermore, the nature of the changes in the evoked potentials were observed to be different. Another feature that distinguishes STEM from LTE is that the induction of LTE is dependent on the NMDA receptor, whereas STEM is NMDA-receptor independent. When rats were anesthetized and their bodies warmed passively, they exhibited STEM-like changes which were highly correlated with body temperature. These temperature-induced changes in evoked potentials had little impact on the functional output of cells in the fascia dentata. It is therefore concluded that exploration-induced changes in the hippocampus are largely due to brain temperature changes and have minimal impact on the functioning of neurons as originally proposed.

Up to date anatomical and biochemistry studies related to Brain mechanisms of behavior are reviewed. This type of research shold be work up in clinical psychology related to prevention, diagnostic and therapy of behavior disorders. In this way, the clinical psychology should make clinical research at differents age groups of the population. He will be able to study epidemiological risk factors together with neuropsychologycal tests and Brain imagind studies.<br>Se presentan los avances en Psicofisiología, destacando los estudios anatómicos y bioquímicos de los mecanismos cerebrales que intervienen en la conducta. Estas investigaciones permiten ampliar el campo de la Psicología Clínica, tanto en la prevención como en el diagnóstico y terapéutica de los desórdenes de la conducta. En este objetivo, el psicólogo clínico podrá realizar estudios de investigación en la comunidad con la metodología de correlacionar factores de riesgo epidemiológicos, tests neuropsicológicos y estudios por imágenes.

Thesis (PhD) - Swinburne University of Technology, Brain Sciences Institute, 2008.<br>[A thesis submitted for the degree of] Doctor of Philosophy, Brain Sciences Institute, Swinburne University of Technology - 2008. Typescript. Includes bibliographical references (p. 250-272) and index.

<p> Biological membranes are important structural units in the cell. Composed of a lipid bilayer with embedded proteins, most exploration of membranes has focused on the proteins. While proteins play a vital role in membrane function, the lipids themselves can behave in dynamic ways which affect membrane structure and function. Furthermore, the dynamic behavior of the lipids can affect and be affected by membrane geometry. A novel fluid membrane model is developed in which two different types of lipids flow in a deforming membrane, modelled as a two-dimensional Riemannian manifold that resists bending. The two lipids behave like viscous Newtonian fluids whose motion is determined by realistic physical forces. By examining the stability of various shapes, it is shown that instability may result if the two lipids forming the membrane possess biophysical qualities, which cause them to respond differently to membrane curvature. By means of numerical simulation of a simplified model, it is shown that this instability results in curvature induced phase separation. Applying the simplified model to the Golgi apparatus, it is hypothesized that curvature induced phase separation may occur in a Golgi cisterna, aiding in the process of protein sorting. </p><p> In addition to flowing tangentially in the membrane, lipids also flip back and forth between the two leaflets in the bilayer. While traditionally assumed to occur very slowly, recent experiments have indicated that lipid flip-flop may occur rapidly. Two models are developed that explore the effect of rapid flip-flop on membrane geometry and the effect of a pH gradient on the distribution of charged lipids in the leaflets of the bilayer. By means of a stochastic model, it is shown that even the rapid flip-flop rates observed are unlikely to be significant inducers of membrane curvature. By means of a nonlinear Poisson- Boltzmann model, it is shown that pH gradients are unlikely to be significant inducers of bilayer asymmetry under physiological conditions. </p>

In this thesis, we report on our studies of water dynamics and structure in various biological environments which include: the surfaces of proteins and various oligosaccharides, the intervening space between proteins; and in the vicinity of cryoprotectant disaccharides in the liquid and ice phases. From a theoretical perspective, we propose methodology to compute diffusivity and residence times on the surface of biomolecules. In particular our proposed algorithm to compute residence times appears to be better in dealing with poor statistics associated with the number of water molecules that remain on a surfaces for extended times. The type of linkage between monomers and the anomeric configuration all play a major role in determining the structure and dynamics of water on the surface of carbohydrates.