Prefrontal cortical subregions bidirectionally control fear extinction through projections to the brainstem noradrenaline system
The brainstem locus coeruleus (LC) is a major source of noradrenaline to the forebrain and plays important roles in emotional learning. Though the LC receives synaptic inputs from the medial prefrontal cortex, a brain region important in cognitive and emotional processing, it is unclear whether and how prefrontal regions influence the LC particularly during fear extinction learning. To address this question, we first examined the detailed anatomical connectivity from prefrontal subregions to the LC in rats. Retrograde and anterograde tracing experiments showed that LC noradrenergic neurons rec