Paeoniflorin inhibits functional responses of rat cerebellar Purkinje cells to acute hypoxia insult

AIM: To investigate the effects of paeoniflorin (Pae) on the functional responses induced by acute hypoxic insult in the rat cerebellar Purkinje cells (PCs).METHODS: The whole-cell patch clamp was used for the intracellular recording of PCs in the rat cerebellar slices to evaluate the changes of membrane potential, the excitability of PCs, and the parallel fibre (PF)-PC excitatory postsynaptic currents (EPSCs) upon acute hypoxic insult alone or with the pre-sence of Pae.RESULTS: PCs showed an initial hyperpolarization followed by brief depolarization and long lasting post-hypoxia hyperpolarization after hypoxia exposure. Pae completely blocked hypoxia-induced hyperpolarization and decreased the amplitude and the duration of hypoxic depolarization. Hypoxia up-regulated the excitability of rat PCs. Pae didn't show any significant effect on the hypoxia-induced hyperexcitability in PCs. Acute hypoxia induced long-term depression (LTD) in rat cerebellar PF-PC EPSCs, and Pae partially reversed hypoxia-induced depression in PF-PC EPSCs.CONCLUSION: Pae significantly suppresses hypoxia-induced responses in rat PCs and probably increases the tolerance of rat PCs to acute hypoxia.