Levels of putative transmitter amino acids in the guinea pig cochlea.

Abstract

Levels of GABA, glycine, glutamate and aspartate were measured in 0.2- to 2-.mu.g samples of tissue dissected from 6 freeze-dried cochleas, each obtained from a separate guinea pig. Low levels of GABA were found in all cochlear regions examined; levels of glycine were high for all regions. Glutamate and aspartate levels were higher in the organ of Corti than in any other cochlear region. There were gradients of aspartate levels along the cochlear length of both inner and outer hair cell regions.