Whole-brain mapping of monosynaptic afferent inputs to the CRH neurons in the medial prefrontal cortex of mice

Corticotropin-releasing hormone (CRH) neurons are densely distributed in the medial prefrontal cortex (mPFC), which plays a crucial role in integrating and processing emotional and cognitive inputs from other brain regions. Therefore, it is important to know the neural afferent patterns of mPFC^CRH neurons, which are still unclear. Here, we utilized a rabies virus-based monosynaptic retrograde tracing system to map the presynaptic afferents of the mPFC^CRH neurons throughout the entire brain. The results show that the mPFC^CRH neurons receive inputs from three main groups of brain regions: (1) the cortex, primarily the orbital cortex, somatomotor areas, and anterior cingulate cortex; (2) the thalamus, primarily the anteromedial nucleus, mediodorsal thalamic nucleus, and central medial thalamic nucleus; and (3) other brain regions, primarily the basolateral amygdala, hippocampus, and dorsal raphe nucleus. Taken together, our results are valuable for further investigations into the roles of the mPFC^CRH neurons in normal and neurological disease states. These investigations can shed light on various aspects such as cognitive processing, emotional modulation, motivation, sociability, and pain.