Lack of effect of DL-α-aminoadipate, an excitatory amino acid antagonist, on cat auditory nerve responses to sound

Abstract

DL-α-aminoadipate, locally applied to the cat cochlea at concentrations of 1 mM and 10 mM, has no effect on the amplitude, latency or shape of click evoked auditory nerve compound action potentials at 5, 10 and 40 dB above threshold. It is concluded that the postsynaptic receptor of the hair cell — auditory nerve synapse is not of the N-methyl-D-aspartate, aspartate-prefering type. The possibility remains that the responses produced by exogenously applied glutamate and aspartate reported by others are the result of an interaction with a non-N-methyl-D-aspartate receptor at the hair cell-auditory nerve synapse or an extrasynaptic receptor.