Temporal And Spatial Expression Patterns Of Gama-Aminobutyric Acid (GABA) In The Developing Cochlea Of Mice

Objective: To detect the temporal and spatial expression patterns of gama-Aminobutyric acid (GABA) in the developing cochlea of mice. Methods: The cochlea of mice at defferent postnatal date from postnatal(P) 1st day to P 14th day was observed under light microscope. The temporal and spatial expression patterns of GABA in the cochlea were observed through immunohistochemical method.Results:The cochlea of P 1st day mice was far under maturation.The layers of cells in the Reissner's membrane and basilar membrane reduced gradually after P 1st day .The quantity of the supporting cells, such as inner sulcus cell, border cell, Hensen's cell decreased.The inner hair cell(IHC) and outer hair cell(OHC) differentiated from shape of cube to flask and test tube respectively.Corti's tunnel, outer tunnel, inner spiral sulcus and stria vascularis came into being at P 14th day. The immunoreactivity of GABA hadn't been found until P 5th day. It located in the region of IHC and Corti's tunnel. It appeared in the first row OHC at P 7th day. The immunoreactivity of GABA spread the whole region of OHC at P9th day. From P 11th day to P14th day, the expression of GAB A didn't change.Conclusion: The cell and structure of the cochlea developed from P 1th dayto P 14th day . At first day after birth, there was no immunoreactivity ofGABA in whole cochlea of mice. It appeared in the internal spiral bundle,Corti's spiral bundle and their axon terminals at P 5th day, then it appeared inthe external radial bundle gradually. GABA might act as one ofneurotransmitters in the efferent nerve system of mice and it might play anrole in the development of the cochlea of mice.