Effect of Electroacupuncture on Learning-memory Ability in Rats with Hypoxic-ischemic Encephalopathy

Abstract

To observe the effect of electroacupuncture (EA) on changes of learning-memory ability, psychomotor coordination and anxiety-like behavior of cerebral hypoxic-ischemia (CHI) young rats, so as to explore its protective effect on neurons under hypoxic-ischemic conditions. SD rats (aged 7 days) were randomly divided into sham operation (sham, n=12), model (n=11), and EA groups (n=12). In addition, 6 young rats in each group were used for observing the number of dendritic spines after Golgi staining. The CHI model was established by ligation of the left common carotid artery combined with hypoxia in a closed transparent vessel. EA was applied to "Baihui" (GV 20)and "Dazhui" (GV 14) for 20 min, once every other day, for 28 days. The rats' behavior changes were assessed by using rotarod performance (for psychomotor coordination), elevated plus maze (anxiety-like behavior) tests and Morris water maze (learning-memory ability) tests, separately. After modeling, the average escape latency and average escape distance of location navigation test within 70 seconds were significantly increased (P<0.05), and the average times and average duration of safe-platform quadrant crossing of spacial probing test were markedly reduced relevant to the sham group (P<0.05). After EA treatment, CHI-induced increases of escape latency and escape distance, and the decreased times and duration of platform quadrant crossing were significantly reversed (P<0.05). No significant differences were found among the three groups in the falling latency of rotarod performance test, and in the time of opening and closing arms of elevated plus maze tests (P>0.05). The density of dendritic spines was significantly lo-wer in the model group than in the sham group (P <0.05), and notably higher in the EA group than in the model group (P<0.05). EA can improve the learning-memory ability of CHI young rats, which may be related to its effect in protecting the dendritic spines of CA 1 region of hippocampus from injury.