Effect of electroacupuncture on behavior and cell apoptosis of brain tissue in traumatic brain injury rats

Abstract

To observe the effect of electroacupuncture (EA) on behavior, pathomorphology and brain cell apoptosis in traumatic brain injury (TBI) rats, so as to explore its mechanisms underlying treatment of TBI. Male SD rats were randomly divided into control (n=10), sham (n=30), model (n=30) and EA (n=30) groups, the latter three groups were further divided into 3, 7, 14 d subgroups （n=10）. TBI model was established by using a free fall brain injury striking device after exposing the local cranial bone (to induce the left parietal cerebral contusion). Twenty-four hours after modeling, EA (2 Hz, 1 mA) was applied at "Quchi"(LI11), "Neiguan"(PC6), "Zusanli"(ST36) and "Yongquan" (KI1) combined with acupuncture at "Shuigou"(GV26) and "Baihui"(GV20) for 15 min, once a day for 14 consecutive days. After 3, 7, and 14 days treatment, the behavioral function (balance, walking, nerve, and limb retraction) of the rats was evaluated. The histopathological changes of the injured brain tissue were observed by HE staining. TUNEL method was used to detect the apoptosis of cells in the brain injury area. After modeling, the scores of balance and walking in the model group were higher than those in the sham group (P<0.01, P<0.05), the neurological function score and the right limb retraction force were lower than those in the sham group(P<0.01). After 3 days treatment, the neurological function score and the right limb retraction force in the EA group were higher than those in the model group (P<0.05). After 7 and 14 days treatment, the scores of balance and walking function in the EA group were lower than those in the model group (P<0.05, P<0.01), while the scores of nerve function and right limb retraction force were higher (P<0.05, P<0.01). HE staining showed that modeling induced pathological changes such as the inflammatory cell infiltration, interstitial edema, necrosis, nuclear pyknosis and nuclear lysis were relatively milder in the EA group on the 7th and 14th day. Compared with the sham group, the cell apoptosis of brain injury area was higher in the model group (P<0.01); while it was lower on day 7 and 14 in the EA group in comparison with the model group (P<0.01, P<0.05). EA can improve the behavioral function, reduce the apoptosis of brain cells in the injured area, and promote the rehabilitation of craniocerebral injury.