ELECTRODERMAL RESPONSE IN NONGLABROUS SKIN OF FREELY MOVING RATS - MEDIATION BY THE SYMPATHETIC NERVOUS-SYSTEM AND EVALUATION IN AN ANIMAL-MODEL OF DEPRESSION

Electrodermal responses in the facial region of freely moving rats wer e recorded bilaterally. After a nociceptive stimulus (ammonia vapor ex posure), the response (a transient negative potential followed by a lo nger-lasting positive potential) attained a similar amplitude on both sides, Surgical sympathetic denervation of facial skin by ipsilateral superior cervical ganglionectomy (SCGx) significantly decreased the el ectrodermal response, When an inferior cervical ganglionectomy was per formed in addition to SCGx, a further decrease in electrodermal respon se was observed, Pretreatment of unilaterally SCGx rats with atropine blunted the electrical response in the control side to levels similar to those found in the SCGx side. Treatment with phenoxybenzamine or pr opranolol was ineffective. Skin potential responses were measured in a dult rats administered with clomipramine from the 8th to the 21st day of life and exhibiting a long-lasting syndrome resembling human depres sion. Clomipramine-injected rats developed larger skin potential respo nses to sound stimulation than controls while responses to ammonia vap or were similar in both groups, as well as the habituation rate after repetitive exposure to ammonia vapor. The results indicate that some o f the altered electrodermal responses found in depressed patients are detectable in the clompramine animal model of endogenous depression.