小脑电刺激对大鼠脑缺血早期神经元线粒体的影响

目的　观察小脑顶核电刺激预处理对大鼠脑缺血早期神经元线粒体的影响。方法　 40只Wistar大鼠随机分为 5组 ,FNS预置组分别给予小脑顶核刺激 (FNS)预处理 1h ,1d及 7d后通过线栓法建立大脑中动脉闭塞 (MCAO)模型 ,3h后取缺血侧大脑组织测定含水量 ,并通过电镜观察缺血区神经元线粒体 ,分析其体密度 (Vv)、面密度 (Sv)及比表面 (Ss) ,结果与假FNS组比较。同时设立正常对照组。其他大鼠则应用鹅膏氨酸 (IBO)预先毁损小脑顶核 (FN) ,5d后再予FNS ,1d后行MCAO。结果　与正常对照组比较 ,假FNS组MCAO后 3h ,缺血侧脑含水量增加 ,神经功能评分降低 ,神经元线粒体Vv及Sv增加 ,而Ss降低 ,两组差异有统计学意义 (P <0 .0 5 ) ;与假FNS组比较 ,缺血前 1d或 7d给予FNS预置 ,脑含水量下降 ,神经功能评分增加 ,线粒体Vv及Sv降低 ,而Ss增高 ,差异有统计学意义 (P <0 .0 5 )。预先使用IBO损毁顶核者 ,FNS的预置保护效应则被消除。结论　预先小脑顶核刺激 ,可抑制大鼠脑缺血早期神经元线粒体的肿胀 ,改善缺血区组织水肿 ,从而减轻神经功能缺损。

Effect of preconditioning electrostimulation of fastigial nucleus on neuronal mitochondrion of rat early after cerebral ischemia

Objective To investigate the effect of preconditioning electrostimulation of fastigial nucleus (FNS) on the neuronal mitochondrion of rats early after cerebral ischemia. Methods Forty Wistar rats were used and divided into 5 groups: a normal control group, a sham FNS group and 3 FNS groups. The FNS of the rats in the FNS groups was conducted for 1 hr, 1 day or 7 days, respectively, before the models of middle cerebral artery occlusion(MCAO)were made with them. Three hours after the model was established, the animals were sacrificed and the water content of the brain of the ischemic side was measured. The neuronal mitochondrion was observed by electron microscope, and its Vv, specific volume (Sv) and specific surface (Ss) were analyzed. The rats in the normal control group were not given any special treatment. For the rats in the sham-FNS group, intrinsic neurons of FN were destroyed with ibotenic acid (IBO), and 5 days later, the FN was electrically stimulated, and 1 day later, MCAO models were made. Results Three hours after MCAO, the water content of the brain increased and neurological function score decreased in the sham-FNS group, while the Vv and Sv of neuronal mitochondrion increased and the Ss decreased, which were significantly different from those of the normal control group(P<0.05). Electrostimulation of the FN for 1 or 7 days before MCAO significantly alleviated the increase of the water content in brain, increased neurological function score, while reduced the Vv and Sv and increased the Ss as compared with the sham-FNS group(P<0.05). Damage of FN abolished the protective effects of the FNS. Conclusion Preconditioning FNS can inhibit neuronal mitochondrial swelling and relieve ischemic brain edema early after cerebral ischemia, thereby alleviate neurological function impairment.