Theta coupling within the medial prefrontal cortex regulates fear extinction and renewal

Fear learning, and its extinction, are fundamental learning processes that allow for a response adaptation to aversive events and threats in the environment. Thus, it is critical to understand the neural mechanismthat underpins fear learning and its relapse following extinction. The neural dynamics within the subregions of the medial prefrontal cortex, including the prelimbic cortex (PL) and the infralimbic (IL) cortex, and functional connectivity between them during fear extinction and its relapse, are not well understood. Using in-vivo electrophysiological recordings in awake behaving rats, we identified increased theta activity in the PL during fear learning and in the IL following extinction. Importantly, the PL-IL theta coupling is significantly enhanced throughout fear learning and extinction, but not in fear relapse. Together, our results provide evidence for the importance of synchronized PL-IL activity to regulate context-dependent retrieval of a fear extinction memory.

Automated summary

Fear learning and its extinction are important processes for responding to aversive events and threats. This study investigated the neural mechanisms underlying fear learning and its relapse. The findings suggest that synchronized activity between the different subregions of the medial prefrontal cortex is crucial for the context-dependent retrieval of fear extinction memory.