Aim: To study the effects of yi-zhi II (a compond of Chinese Traditional Medicine) on the alteration of synaptic structure in hippocampal CA3 and maintenance of memoy.
Methods: By using the method of oral administration of yi-zhi II, the step-through test and electron microscopy, the latency of step-through and synaptic structure in hippocamal CA3 were tested.
Results: (1) The mice which had been given yi-zhi II prolong significantly the latency of step through (P < 0.05 or P < 0.01) on the 1st, 6th and 12th day after learning. (2) On the 6th and 12th day after learning, the length of synaptic active zone were markly improved in yi-zhi II and control, but that of yi-zhi II was better than that of control. (On the 6th day after learning, the number of perforated synapses and axo-dendrite synapses were significantly improved by the yi-zhi II (P < 0.05).
Conclusion: The yi-zhi II could improve the learning and memory in mice. It migth improve the memory by increasing the length of synaptic active zone and the number of perforated synapses and axo-dendrite synapses in hippocampal CA3.