[Effects of glycine and GABA on primary afferent terminal excitability in mouse spinal cord]

The effects of GABA, glycine and their antagonists on primary afferent terminal excitability were observed on isolated spinal cord of 10-15 day-old mouse. The results indicated that electrical stimulation of an adjacent dorsal root and electrophoresis of GABA, Thip., thiomuscimol and glycine can evoke a fall in threshold, the excitability of single primary afferent terminal was increased. Bicuculline, an antagonist of GABA receptor, can block effects of GABA, Thip. and thiomuscimol, but it has no effect on glycine. However, strychnine, an antagonist of glycine, can block the effect of glycine but not to GABA. These results suggest that there are GABA and glycine receptors on primary afferent terminals of mouse spinal cord and the type of glycine receptor may be the same as neuron body.