AGE-RELATED GLYCINE RECEPTOR SUBUNIT CHANGES IN THE COCHLEAR-NUCLEUS OF FISCHER-344 RATS

Previous studies have shown that levels of binding for the strychnine- sensitive glycine receptor in the cochlear nucleus (CN) of Fischer (F3 44) rats decrease with age. Given the major role glycine plays in norm al CN function, changes in glycine-receptor activity may contribute to central presbycusis. To further evaluate the impact of age on glycine receptors, in situ hybridization was used to assess;,in three age gro ups of F344 rats, changes in levels of gene expression for four of its subunits. When compared with the 3-month-old rats, expression of mRNA s for alpha 1 and beta subunits in the anteroventral ?CN decreased sig nificantly in the 18- and 27-month-old age groups, while mRNA expressi on for the alpha 2 subunit increased. If protein expressions are simil ar, these subunit changes may alter the function of glycine receptors, thereby affecting binding to its ligands.