Action of Tubocurarine and Atropine on the Crossed Olivocochlear Bundles

Abstract

The effect of atropine and d-tubocurarine chloride on the cochlear potentials and modification of the cochlear responses caused by electrical stimulation of the crossed olivocochlear bundles was examined in guinea pigs. Intravenous injection of gallamine triethiodide did not alter the inhibitory action of the crossed olivocochlear bundles. Section of the crossed olivocochlear bundles did not result in suppression of the cochlear microphonics. Perfusion of the scala tympani with Ringer' containing atropine or d-tubocurarine chloride did not alter the cochlear potentials but did block their responsiveness to the stimulation of the crossed olivocochlear bundles. The blocking activity of these anticholinergic drugs implies that acetylcholine is the possible transmitter of the crossed olivocochlear bundles.