OBJECTIVETo evaluate the effect of Wulongdan, a tradition Chinese medicinal preparation, on the learning and memory abilities of rats with chronic cerebral ischemia and explore the mechanisms.

METHODSMale rats with chronic cerebral ischemia induced by permanent ligation of the bilateral carotid arteries were randomized into sham-operated group, chronic cerebral ischemia (model) group, and high-, middle-, and low-dose Wulongdan groups and Yinxingye group. The corresponding treatments were administered in the rats 24 h after the operation once daily for 8 consecutive weeks. Morris water maze and step-through tests were performed after 7 weeks of drug administration. The brain tissues were then taken to observe the morphological changes in the hippocampal neurons with Nissl staining by transmission electron microscopy.

RESULTSCompared with the model group, the latency of finding the platform in Morris water maze test was significantly shortened (P<0.05 or 0.01), and that in step-through test significantly prolonged (P<0.05 or 0.01) in high-, middle-, and low-dose Wulongdan groups and Yinxingye group. In the model group, Nissl staining of the hippocampal CA1 region visualized obvious pathological changes in the neurons, showing a significant difference from the sham-operated and high-dose Wulongdan groups.

CONCLUSIONWulongdan can enhance the learning and memory abilities of rats with chronic cerebral ischemia possibly through a mechanism in relation to neuronal protection in the hippocampus CA1 region.