Zhengtian Pills accelerated long term potentiation both in Schaffer collateral -CA1 and perforant path-dentate gyrus synapses

Abstract Objective To investigate the effects of Zhengtian Pills (ZTP) on long term potentiation (LTP) both in Schaffer-CA1 in vitro and perforant path-dentate gyrus (PP-DG) synapses in vivo . Methods Sprague-Dawley rats were randomly divided into five groups: control, positive control, migraine model, low-, and high-dose ZTP groups. Glyceryl trinitrate (10 mg/kg) was injected subcutaneously to make migraine rat model. Flunarizine (0.9 mg/kg) was set as positive control. Extracellular recording technique in vivo was used to record the effects of ZTP on LTP of PP-DG pathway in anesthetized rats; Using extracellular recording technique in vitro , the effects of ZTP on LTP of Schaffer Collateral-CA1 pathway in rat hippocampal slices were investigated. Results Compared to the control group, ZTP (1.08 g/kg) significantly enhanced population spike amplitude in PP-DG pathway; Glyceryl trinitrate (10 mg/kg) significantly reduced population spike amplitude in PP-DG pathway; Neither ZTP (0.54 g/kg) nor Flunarizine (0.9 mg/kg) had significant effects on LTP in PP-DG pathway. Compared to the model group, ZTP (1.08 g/kg), ZTP (0.54 g/kg), and flunarizine (0.9 mg/kg) significantly enhanced population spike amplitude in PP-DG pathway. Compared to the control group, ZTP (1.08 g/kg) significantly enhanced field excitatory postsynaptic potential (fEPSP) slope in Schaffer Collateral-CA1 pathway; Glyceryl trinitrate (10 mg/kg) significantly reduced fEPSP slope in Schaffer Collateral-CA1 pathway; Neither ZTP (0.54 g/kg) nor flunarizine (0.9 mg/kg) significant effects on LTP in Schaffer Collateral-CA1 pathway, Compared to the model group, ZTP (1.08 g/kg), ZTP (0.54 g/kg), and Flunarizine (0.9 mg/kg) had significantly enhanced fEPSP slope in Schaffer Collateral-CA1 pathway. Conclusion Combined with the previous study, the results gave a clue that the effects of ZTP on TRPV1 and hippocampal LTP or their interactions could be the important molecular mechanisms of ZTP acting as migraine and headache medication.