[Changes of GABA immunoreactivity in aged rat cochlear nucleus].

OBJECTIVES

To detect the changes of gama-aminobutyric acid (GABA) immunoreactivity in the aged rat cochlear nucleus and to investigate its relationship with the initiation of presbycusis.

METHODS

The cochlear nucleuses of adult (2-3 months) and aged (20-36 months) Wistar rats were stained with streptavidin/peroxidase (S-P) technique. GABA-positive neurons were counted with a computer-aid image analysis system.

RESULTS

Most of the GABA-immunoreactive cell bodies were found in the superficial layers of the dorsal cochlear nucleus (DCN). The number of GABA-positive neurons decreased significantly in the DCN of the aged rat cochlear nucleus (P < 0.001).

CONCLUSION

The reduction of GABA positive neurons in the aged rat cochlear nucleus may be related to presbycusis.