Recent findings have shown that the auditory cortex, and specifically the higher order Te2 area, is necessary for the consolidation of long-term fearful memories and that it interacts with the amygdala during the retrieval of long-term fearful memories. Here, we tested whether the reversible blockade of Te2 during memory consolidation may affect the activity changes occurring in the amygdala du...

There is strong evidence that two cerebral hemispheres are differentially involved in emotional memory and that amygdala is a key subcortical structure for emotional experience. The present research investigated the possible involvement of lateralization of basolateral amygdala (BLA) and central amygdala (CEA) in place avoidance memory. For this purpose, male Long-Evans rats (280-320 g) were im...

The recently discovered neuropeptide orphanin FQ (OFQ), and its opioid receptor-like (ORL1) receptor, exhibit structural features suggestive of the micro, kappa, and delta opioid systems. The anatomic distribution of OFQ immunoreactivity and mRNA expression has been reported recently. In the present analysis, we compare the distribution of orphanin receptor mRNA expression with that of orphanin...

We investigated the involvement of the adrenal glucocorticoid, corticosterone, in the control of the rhythmic expression of the circadian clock protein, Period2, in forebrain nuclei known to be sensitive to glucocorticoids, stressors and drugs of abuse, the oval nucleus of the bed nucleus of the stria terminalis and the central nucleus of the amygdala. We found previously that the daily rhythm ...

Conditioned defeat is a model wherein hamsters that have previously experienced a single social defeat subsequently exhibit heightened levels of avoidance and submission in response to a smaller, non-aggressive intruder. While we have previously demonstrated the critical involvement of the basolateral and central nuclei of the amygdala in the acquisition and expression of conditioned defeat, th...

The medial prefrontal cortex has been associated with diverse functions including attentional processes, visceromotor activity, decision-making, goal-directed behavior, and working memory. The present report compares and contrasts projections from the infralimbic (IL) and prelimbic (PL) cortices in the rat by using the anterograde anatomical tracer, Phaseolus vulgaris-leucoagglutinin. With the ...

The mechanisms underlying learning in classical conditioning experiments play a key role in many learning processes of real organisms. This paper presents a novel computational model that incorporates a biologically plausible hypothesis on the functions that the main nuclei of the amygdala might play in first and second order classical conditioning tasks. The model proposes that in these experi...

The amygdala is known to be a critical mediator of emotional learning in aversive and appetitive conditioning. Here we show for the first time that distinct subregions of the amygdala play unique roles in the acquisition and expression of cocaine-seeking behavior maintained by drug-paired cues in a model of relapse. Reversible inactivation of the basolateral amygdala with the sodium channel blo...