Effects of drugs on the reflex response of the cervical vagus nerve.

FiG. 1. Effects of strychnine (100 tcg/kg, i.v.), mephenesin (30 mg/kg), pentobarbital (15 mg/kg), GABA (200 mg/kg) on the reflex response of the right cervical vagus nerve. In each series of record from above downwards : reflex responses to the stimulation of the left cervical vagus, great splanchnic and sciatic nerves. Strychnine (A) augmented and mephenesin (B) reduced mainly the reflex response to the stimulation of the sciatic nerve. Pentobarbital (C) reduced or abolished all reflex responses. However, the third component of response to the vagus nerve stimulation and the first component of response to the great splanchnic nerve stimulation rather resisted. GABA (D) reduced only the third component of response to the vagus nerve stimula tion. Arrow indicates the administration of drug, and white dot supramaximal single shock stimulation on each nerve. Time scale : 50 msec.