Presynaptic control of efficacy of GABAergic synapses in the hippocampus
First we found that applying substances that change intracellular presynaptic GABA concentration alter the synaptic efficacy of hippocampal GABAergic neurons. The amplitude as well as the frequency of occurrence of spontaneous postsynaptic currents (mIPSCs) are affected. Then, we developed a model of presynaptic vesicle dynamics to better understand the causal relationship between cytosolic GABA concentration and mIPSC amplitude and frequency. One way to explain our experimental findings is to postulate that the filling of vesicles as well as their transition into the readily releasable pool depends on vesicular GABA content.
readily releasable pool synaptic plasticity metabolism vesicle cycle