Effect of Liuwei Dihuang decoction ("Equation missing" ) on long-term potentiation in hippocampal dentate gyms in rats) on long-term potentiation in hippocampal dentate gyms in rats

Abstract

Objective: To investigate effect of Liuwei Dihuang decoction (LWDHD), a traditional Chinese medicinal prescription, on the formation of long-term potentiation (LTP) in the hippocampal dentate gyrus in anesthetized rats.Methods: LTP experiments were conducted by using a bipolar stimulating electrode to stimulate perforant pathway and a monopolar electrode to record the evoked field potential in hippocampal dentate gyrus. In the present study, both suprathreshold and subthreshold tetanic stimulation to the perforant pathway were employed.Results: Single oral administration of LWDHD (per os, 5 g/kg and 10 g/kg respectively) has no effect on the basal spike amplitude. However, LWDHD (per os, 5 g/kg and 10 g/kg respectively) significantly intensified the spike amplitude induced by a subthreshold stimulation (60 Hz, 20 pulses) while it did not affect formation of LTP formation induced by suprathreshold tetanic stimulation (60 Hz, 30 pulses).Conclusion: The present results suggested that LWDHD given orally potentiate the synaptic plasticity and transmission in hippocampal dentate gyrus, which might account for the enhancing effect of LWDHD on learning and memory in senescence-accelerated mice.