Stress effects on the balance between memory systems

描述（由申请人提供）： 这个提议研究了慢性压力对多个记忆系统之间平衡的影响。 慢性压力会损害许多任务的学习和记忆，尽管有一些报告表明慢性压力对学习没有影响或增强了学习。目前的研究结果表明，不同的记忆系统相互作用的方式，包括竞争的情况下，往往表现为显示病变或药理学失活的一个系统可以增强学习的任务通常与不同的神经系统。通过使用在体内微透析耦合到敏感的测定程序，它是可能的，以检查释放乙酰胆碱在迷宫训练大鼠的过程中，与样品收集时间，以匹配只有少数的训练试验。这些研究的结果表明，几个神经系统中乙酰胆碱的释放是一个有用的标志，表明一个系统被训练激活的程度。例如，当大鼠在T型迷宫上训练时，可以使用位置（视皮层依赖性）或反应（纹状体依赖性）溶液来学习，训练前和训练期间的乙酰胆碱释放预测哪些大鼠使用每种溶液。 这项建议将使用这些程序来确定慢性压力是否会产生一种转变，在这种转变中，神经系统在学习过程中被优先激活，从而损害某些任务的学习，并增强其他任务的学习。此外，这项建议将同时检查海马和纹状体中乙酰胆碱的释放，在基线和训练的反应，以确定是否慢性应激导致不同的配置文件的乙酰胆碱释放与认知过程的变化。因此，这些实验的结果可能提供了一个基础，明显不一致的行为发现后，慢性压力。更一般地说，这些发现解决了一个关键问题，即慢性压力是否会导致神经系统之间的平衡发生变化，从而改变老鼠面对新问题时选择的策略。

DESCRIPTION (provided by applicant): This proposal examines the effects of chronic stress on the balance between multiple memory systems. Chronic stress impairs learning and memory on many tasks, though there are some reports of no effect or enhanced learning after chronic stress. Current findings indicate that different memory systems interact in a manner that includes instances of competition, often demonstrated by showing that lesions or pharmacological inactivation of one system can enhance learning of a task typically associated with a different neural system. By using in vivo microdialysis coupled to sensitive assay procedures, it is possible to examine release of acetylcholine during the course of training rats in mazes, with sample collection timed to match only a few training trials. Findings from studies such as these have shown that release of acetylcholine in several neural systems is a useful marker of the extent to which a system is activated by training. For example, when rats are trained on a T-maze that can be learned using either place (hippocampus-dependent) or response (striatum-dependent) solutions, acetylcholine release before and during training predicts which rats use each solution. This proposal will use such procedures to determine whether chronic stress produces a shift in which neural system is preferentially activated during learning, thereby impairing learning of some tasks and enhancing learning of other tasks. In addition, this proposal will examine simultaneously acetylcholine release in the hippocampus and striatum, at baseline and in response to training, to determine whether chronic stress results in different profiles of acetylcholine release associated with changes in cognitive processing. Thus, the findings of these experiments may offer a basis for apparently discrepant behavioral findings after chronic stress. More generally, the findings address the key issue of whether chronic stress results in a change in the balance between neural systems, thereby altering the strategy selected by a rat faced with a new problem to solve.