[The effects of muscarinic and nicotinic receptor antagonists on compound action potentials in the cochleae of gerbils].

To explore the mechanism of the medial olivocochlear(MOC) efferents and their neurotransmitter acetylcholine in regulating the cochlear mechanics and the auditory afferent activities, the effects of contralateral noise(CLN) and muscarinic(M) and nicotinic(N) receptor antagonist on the compound action potential(CAP) of the cochleae of gerbils were observed in our studies. The results showed that the CAP was significantly inhibited by CLN, and the suppressive effect of CLN on CAP was eliminated either by atropine or by gentamycin. These results support that MOC efferents play their physiological effect via both M and N receptors.