Age-related changes in [3H]strychnine binding in the vestibular nuclei of rats

Glycine plays an important role as a neurotransmitter in the four vestibular nuclei (VN). The objective of this study was to determine if the levels of glycine-receptor binding in the VN change as a function of age. Quantitative receptor autoradiography was performed on brainstem sections from three age groups (3, 18 and 26 months) of Fischer 344 rats to assess binding in the VN. Glycine receptors were localized using [3H]strychnine binding. Strychnine binding declined monotonically with increasing age, such that the level of strychnine binding in each of the VN in the 28-month-old animals was approximately one-half that in the 3-month-olds. The age-related decrease in levels of strychnine binding suggest altered glycinergic function in the VN, which may in turn contribute to disturbances in equilibrium observed in the elderly.