Neural Mechanisms of trace auditory fear conditioning

This project focuses on the role of different memory systems in trace auditory fear conditioning (tAFC). Our aim is to unravel how the association between two stimuli separated in time is formed in the brain. Preliminary findings led us to hypothesize that the strategy used by the rats to learn the association between tone and shock depends on the length of the trace interval between the two stimuli. In accordance with these results we found that temporary inactivation of the hippocampus affects tAFC only when long trace intervals are used. In contrast, inactivation of either the medial prefrontal cortex (mPFC), thought to be important for working memory, or the amygdala, important for fear learning, disrupts learning irrespective of interval length. We have begun to test the role of mPFC –amygdala and mPFC-hippocampus connections in the acquisition tAFC with both short and long trace intervals.