Participation of L-type voltage-gated calcium channels in facilitation of long-term potentiation during the formation of morphine dependence in rats.

摘要

Parameters of long-term potentiation in the system mossy fibers-CA3 pyramidal neurons in hippocampal slices in experimental animals vary during the formation of chronic opiate dependence. During the first day of morphine treatment, the value of potentiation was significantly lower than in controls. Starting from day 8 and at early stages of dependence (days 25-29), facilitation of long-term potentiation was recorded. Incubation of the slices with L-type Ca(2+)-channel blocker nifedipine did not change the response to the test stimuli and did not affect potentiation induction in hippocampal slices from control and morphine-treated animals. Nifedipine had no effect on long-term potentiation of mossy fibers in the control and at early terms of morphine treatment, but significantly reduced its facilitation at later terms.