[Pre- and Postsynaptic Mechanisms of the Deprivational Potentiation of Population Responses in Rat Hippocampal CA1 Neurons].

Mechanisms of the deprivational potentiation (DeP) of the population responses in rat hippocampal CA1 neurons after 60-min period of the cessation of rare (0.05 Hz) test stimulation of Schaffer collaterals was investigated in vitro. It has been demonstrated that two independent mechanisms are involved in DeP induction: presynaptic component in initial phase of DeP and postsynaptic one responsible for the long-term phase of DeP. The competitive interference between mechanisms of the long-term phase of DeP and the protein phosphorylation phase of long-term potentiation (LTP) was confirmed. It was shown that not NMDA receptors, but purinergic P2 receptors participate in Ca(2+) -dependent mechanism of induction of the postsynaptic component of DeP. The common curve of dependence of synaptic strength on synaptic use/disuse, including the DeP, long-term depression (LTD) and LTP areas, is presented.