Objective: To investigate the effect of manual acupuncture on long-term potentiation (LTP) in CA 1 area in hippocampal slices from rats suffered from diabetes mellitus (DM) and cerebral ischemia (CI).
Methods: A total of 54 female Wistar rats were randomly divided into 5 groups: normal control (Con), CI, DM + Sham-CI, DM + CI and DM + CI + acupuncture (Acup). DM model was established by i.p. of streptozotocin (60 mg/kg), and CI model duplicated by bilateral common carotid arteries occlusion and reperfusion. "Baihui" (GV 20), bilateral "Sanyinjiao" (SP 6) and "Pishu" (BL 20) or "Baihui" (GV 20), bilateral "Shenshu" (BL 23) and "Zusanli" (ST 36) were punctured alternatively and stimulated manually, once every other day for 15 times. Hippocampal slices were taken 40 days after modeling. LTP in hippocampal CA 1 induced by high frequency stimulation (100 Hz, 100 pulses) of Schaffer collaterals and population spikes (PS) were recorded by using glass micropipettes.
Results: No significant differences were found between DM + CI and normal control groups in the shape and amplitude of PS (P>0.05). After stimulation of Schaffer collaterals, the amplitude and slope rate of PS in hippocampal CA 1 of DM + CI rats were decreased significantly in comparison with normal control group (P<0.05, P<0.01). While compared with DM + CI group, both the amplitude and slope rate of PS in DM + CI + Acup group increased significantly (P<0.05, P<0.01), suggesting basic restoration of LTP after acupuncture.
Conclusion: Acupuncture can promote the recovery of DM+CI induced decline of the amplitude and slope rate of PS, which may contribute to its effect in improving memory ability in DM + CI rats through regulating hippocampal neuronal synaptic plasticity.