CRH and depressive disorder: Previously, we examined the involvement of 5-HT and CRF neurons in acute exercise-induced changes in depression-related behavior in rats and reported that low-intensity (15 m/min, 30 min), but not high-intensity (25 m/min, 30 min) acute exercise activated DRN 5-HT neurons without producing a high activation of PVN CRF neurons, and thus may effectively improve depression-related behavior [14, 20].