LOCAL INFUSION OF BRAIN-DERIVED NEUROTROPHIC FACTOR MODIFIES THE FIRING PATTERN OF DORSAL RAPHE SEROTONERGIC NEURONS

Previous studies have reported a neuromodulatory effect of brain-deriv ed neurotrophic factor (BDNF) on serotonin neurons in the central nerv ous system. In the present study, we examined the effects of local inf usion of BDNF on the electrophysiological activity of serotonergic neu rons in the rat dorsal raphe nucleus with extracellular single unit re cording in vivo. Compared with vehicle-infused rats, chronic administr ation of BDNF (10-14 days) caused serotonergic neurons to fire in a si gnificantly less regular pattern, without altering the mean firing rat e or other measures of electrical activity. These results suggest that the ability of similar infusions of BDNF to produce behavioral effect s (i.e. analgesia and an antidepressant-like effect) associated with e levated serotonin turnover may be in part the result of more irregular firing patterns of dorsal raphe neurons.