Final Report Summary - AMY-MPFC-EXTINCTION (Functional connectivity between the primate amygdala and the medial prefrontal cortex: role in extinction of emotional memories.)
The major goal of this project was to establish a laboratory that investigates the brain mechanisms that underlie extinction of negative emotional learning and memory. Extinction is an important process by which previously formed negative associations are being reversed i.e. the dangerous stimulus becomes safe. Failure to update such memories- to extinguish properly, can result in anxiety-disorders and post-traumatic-stress-disorder (PTSD). Indeed, this is the major model for PTSD, and extinction is the basis for expousre-therapy, which is the main behavioral tool for treatment of anxiety and PTSD. However, the exact brain mechanisms in the primate remain vague. We focused on interactions between the amygdala - a brain region highly involved in emotional memory and anxiety, and the prefrontal cortex - a brain region known to modulate the amygdala and emotions. We established a primate model for emotional learning, using tone-odor conditoning, and tested it on humans and non-human primates. We tracked the neural codes that underlie learning of positive vs. negative memories, extinction of negative memories, and failure to extinguish it. Importantly, we showed that we can manipulate directly this neural pathway (cortex-amygdala) and prevent recovery of aversive memories, hence suggesting a tool to be tested in further clinical implications. The results shed light on the mechanisms in this pathway and may suggest ways to further manipulate neural information transfer in it in order to reduce the effect of aversive memories and help extinguish them.