Morphological Study On GABA-And SP-Like Immunoreactive Structures In Guinea Pig Auditory System

1. Immunohistochemical distribution and fine localization of the gama-aminobutyric acid in the organ of Corti of normal guinea pig.GABA-TR was found in axons of efferent neurons in all turns of the cochlear spiral, but no positive endings were found in the apical turn. The positive products were distributed in the components,including inner spiral bundle, tunnel spiral bundle, tunnel-crossing fibers , and forming " railway-like" structure. At the bases of outer hair cell (OHC) ,there were GABA-IR positive nerve endings, among them there were some negative OHC. One GABA-IR positive nerve fiber could form synapse with 6-7 OHCs. Under TEM, GABA-IR positive efferent endings, negative efferent endings and negative afferent endings could be seen on the OHC bases. GABA-IR positive efferent endings and negative afferent endings formed axo-dendritic synapses on the inner hair cells bases. These morphological distribution suggests that the GABA may be one of the cochlear efferent neurotransmitters.2. Effects of blast wave on GABA-immunoreactive positive products in...