Electroacupuncture attenuates both glutamate release and hyperemia after transient ischemia in gerbils

Although many studies have indicated that electroacupuncture (EA) provides a neuroprotective effect against ischemic brain damage, the protective mechanism is not fully understood. Glutamate release and hippocampal blood flow in ischemia with EA were investigated to elucidate the neuroprotective mechanism of EA. Transient 5-minute ischemia was induced in gerbils. EA (7 Hz, 6 mA, for 30 minutes) delivered to the points called Fengfu (GV16) and Shendao (GV11) was administered pre-, intra- or post-ischemia. The procedure rescued hippocampal neurons from ischemic insult and significantly attenuated both ischemia-induced glutamate release and transient increase of cerebral blood flow (CBF) during reperfusion (hyperemia). Hyperemia as well as excessive glutamate after ischemia are regarded as important factors in brain damage as they lead to reperfusion injury. These results suggest that EA protects neurons by suppressing both glutamate release and reperfusion injury after ischemia.