Analysis of inhibitory influence of bulbar reticular formation upon sudomotor activity.

Current interest in the influence exerted by the brain stem reticular formation upon somatomotor and autonomic functions has resulted in the publication of numerous papers.As far as autonomic functions are concerned, however,only a few attempts have been made to investigate the mechanism whereby the observed actions of this integrative center are effected. Recently,it has been demonstrated by WANG and BROWN(1956)that the galvanic skin reflex(the GSR)of the cat is a suitable indicator for studying central inhibition of autonomic reflex,and that stimulation of the bulbar ventromedial reticular formation causes inhibition of the GSR. In the present study,therefore,an attempt has been made to analyze inhibitory effect of the bulbar reticular formation upon the sudomotor activity, in order to gain some understanding of the mechanisms of reticular inhibition of the autonomic founctions.The previous study(WANG and BROWN,1956) has dealt mainly with the GSR evoked by stimulation of the peripheral sensory nerve.The present paper differs from it in the point that changes in the level of skin potential resultant from brain stimulation were also investigated together with changes in the amplitude of the GSR.