Effects of Liuwei Dihuang decoction on ion channels and synaptic transmission in cultured hippocampal neuron of rat

The effect of Liuwei Dihuang decoction (LW), a traditional Chinese medicine (TCM) prescription, on voltage-dependent currents and synaptic transmission were investigated in cultured hippocampal neurons of rat by whole-cell patch clamp recording technique. After application with serum from LW-treated rats, termed LW-containing serum (LWCS) for 48 h, the amplitude of delay rectifying K+ current (IK) and voltage-gated Ca2+ current (ICa) decreased. While the frequency of spontaneous excitatory post-synaptic current (sEPSC) and miniature excitatory post-synaptic current (mEPSC) increased significantly. Yet the amplitude of voltage-depended Na+ current (INa) and transient outward K+ current (IA), membrane capacitance and resistance remained unchanged. The results indicated that LWCS possessed the effect of modulating or improving neuronal and synaptic function, which possibly contribute to the cognition enhancing effect of LW.