Involvement of the glutamatergic and gabaergic systems in the dorsal subiculum on the processes of acquisition and memory consolidation in aversive learning tasks in rats

Abstract

It has been proposed that the subiculum is a fundamental piece in the neural circuitry that involves hippocampal formation, besides presenting connections with areas such as prefrontal cortex and amygdala. These regions are extensively studied regarding to their involvement with aversive learning, which is studied through the paradigms of fear conditioning and inhibitory avoidance. We observe the differential involvement of NMDA receptors in these structures in different aspects of aversive learning, as in the processes of memory acquisition and consolidation. The possible involvement of these receptors in the subiculum with aversive learning, however, is still unclear. In addition, the temporary inactivation of this region with muscimol may present different results from those found through NMDA blockade. On the other hand, divergent results when aversive learning is evaluated by different tasks are reported, which may suggest distinct neural circuits underlying these ones. Thus, studies investigating the neurochemical involvement of this structure in aversive learning, considering the possible differences in terms of neural circuitry between these experimental paradigms, are demanded. In this regard, the present project proposes, in general, to evaluate the involvement of the NMDA receptors in the subiculum and the consequences of the temporary inactivation of this region in aversive learning tests in rats. Specifically, we will analyze the effect of the administration of AP-5 and muscimol in the dorsal subiculum on the acquisition and consolidation of memory in the tasks of contextual fear conditioning and inhibitory avoidance. (AU)