Mechanisms of Appetitive and Aversive Context Learning

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DESCRIPTION (provided by applicant): Contextual variables play important roles in the development, treatment, and relapse of many psychiatric disorders, including posttraumatic stress disorder, depression, and substance abuse. Understanding the mechanisms that allow contextual information to be acquired has been critical to the development of treatments for these disorders. The study of contextual learning has also been instrumental in determining the associative and neurobiological mechanisms that underlie learning and memory in general. At the neurobiological level, much of what is known about contextual learning comes from the analysis of context evoked fear, a robust hippocampus-dependent learning process that occurs after a single experience of a shock in a conditioning context. Studies of contextual fear in inbred and genetically modified mice have helped to delineate many of the genetic and molecular mechanisms of memory. The two specific aims in this B/START application are designed to expand the analysis of contextual learning in mice to include both contextual fear conditioning and appetitive contextual conditioning. In Specific Aim 1, C57BL/6 and DBA mice, two inbred strains with well-documented differences in contextual fear, will be compared in acquisition and expression of contextual fear and appetitive contextual conditioning using a magazine approach procedure. By using several different conditioning protocols, I will be able to determine the extent to which contextual learning deficits generalize from aversive to appetitive preparations. In Specific Aim 2, the associative structure of appetitive contextual conditioning will be examined to determine the content of the association that is formed during contextual conditioning. Experiments in this aim will allow me to assess the relative contribution of context-response and context-outcome associations to behavior. These experiments will lay the groundwork for a research program that is focused on asking questions about the nature of specific contextual associations in learning and memory.