Understanding the roles of CRF neurons beyond the HPA axis

Abstract

While animals encounter a wide range of environmental stimuli, they need to quickly determine whether the stimuli are beneficial or detrimental to their survival and whether they should be approached or avoided. How is sensory information of opposing valences represented and evaluated in the brain to produce discrete behavioral outputs? Neurons releasing corticotropin-releasing factor in the paraventricular nucleus of the hypothalamus (PVN) has been known important for regulating the hypothalamus-pituitary gland-adrenal axis. By employing the technical advancements to measure and perturb the activity of these neurons in millisecond scale of behaving mice, using fiber photometry and optogenetic manipulations, we revealed the bidirectional neuronal dynamics of CRF neurons toward environmental stimuli. Notably, we revealed how rewarding stimuli affected the activity of CRF neurons and their associated behavioral functions. These studies will shed light on the understanding of CRF neurons and their importance as a plausible hub to integrate exteroceptive and interoceptive stimuli for behavioral and neuroendocrine regulation in the mammalian systems in the future.