Synaptic Efficacy Is Controlled by the Concentration of Transmitter in the Nerve Ending
Plastic changes related to the quantity of transmitter released per impulse have been more or less directly correlated with induced changes in calcium influx (Kandel and Schwartz, 1982; Alkon, 1986; Krnjevic, 1986), which is known to trigger the transmitter release. As the cytosol of the presynaptic terminal is a site for other intensive events (which regulate the metabolic equilibrium of its molecular constituents), it seems legitimate to ask whether other processes than calcium concentration can influence the quantity of transmitter released. In particular, it was found that in stimulated nervous tissues the transmitter content varies, and it is tempting to consider a possible control of transmitter release by the presynaptic intracellular transmitter concentration. We attempted to obtain evidence for such an effect on a central cholinergic synapse.
KeywordsTransmitter Release Synaptic Efficacy Postsynaptic Response Choline Oxidase Cholinergic Synapse
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