Abstract
Co-release of glycine and GABA is established in which both are co-accumulated into the same synaptic vesicles in the spinal network. Here we show that the pattern of spontaneous miniature inhibitory postsynaptic currents (mIPSCs) and focal evoked IPSCs (eIPSCs) eliciting from a single synaptic terminal depends on the preferential uptake of glycine and GABA into the synaptic vesicles. Long time exposure with bafilomycin A1, a vacuolar-type H+/ATPase inhibitor, decreased in the mIPSC frequency and amplitude. During washing out bafilomycin A1, recovery of GABAergic mIPSCs was slower than for glycinergic mIPSCs as well as that of GABAergic components in the mixed (glycinergic/GABAergic) mIPSCs. Focal stimulation of a single inhibitory synaptic terminal revealed that glycine and GABA are randomly co-released from the synaptic terminals. This suggests that the uptake of glycine and GABA may provide selectivity to the synaptic vesicles. [Jpn J Physiol 54 Suppl:S148 (2004)]
