前庭刺激激活大鼠内侧前额叶皮质神经元Fos表达

Vestibular stimulation induced activation of neurons to express Fos in medial prefrontal cortex of rat

目的:分析对比加伐尼刺激(Galvanic stimulation)与双轴旋转运动分别作用于大鼠前庭器官对内侧前额叶皮质(mPFC)神经元活动的影响。方法:将雄性SD大鼠随机分为4组:电刺激组、对照组、双轴旋转运动组和对照组。电刺激组动物以100~200μA电流强度刺激前庭感受器1 h后休养1 h;双轴旋转组动物以双轴旋转运动刺激2 h。应用包含mPFC的25μm脑冠状切片,以免疫组织化学抗生物素蛋白-生物素复合物(ABC)技术进行Fos蛋白免疫反应并以3,3′-二氨基联苯胺(DAB)显色。最后,对mPFC内标记神经元进行计数和统计分析。结果:动物经两种类型分别刺激后,mPFC均见到大量Fos样免疫阳性反应神经元细胞核;曼-惠特尼U检验统计表明每种刺激条件下,刺激组较对照组动物mPFC内Fos阳性神经元数目都有显著增加(P<0.05)。半定量统计显示两种类型刺激后,接受刺激组和对照组动物mPFC内Fos阳性神经元数目激活的神经元数目分别是1053±240.50 vs 44.25±3.64和509.80±54.40 vs 128.30±7.66。结论:诱发晕动病的双轴旋转刺激和伽伐尼刺激前庭器官均能激活内侧前额叶皮质的神经元,提示mPFC是接受、加工前庭信息的皮层结构。

Objective:To analyze and compare the effects of galvanic and double-axis rotation stimulations on the activity of neurons in medial prefrontal cortex(mPFC)of rat.Methods:Male SD rats were randomly divided into four groups of four rats each:electrical stimulation group vs control group,and double-axis rotation group vs control group.In the electrical stimulation group,the bilateral vestibular receptors of each individual were stimulated with 100~200μA current intensity for one hour succeeded by one-hour respite.Rats in rotation group were stimulated with double-axis rotation for two hours.By using avidin-biotin complex(ABC)method,coronal slices 25μm thick containing mPFC were processed for immunoreactivity for Fos protein,and the color reaction was achieved by using 3,3′-diaminobenzidine method(DAB)as the chromogen.Finally,the Fos-labeled neurons were counted and analyzed statistically.Results:Following two different types of stimulations of the animals,mPFC showed great number of neurons with positive Fos immunoreactivity.Statistically,either type of stimulation induced significantly increased the number of Fos-postive mPFC neurons when compared with the respective control group(P<0.05).Following Galvanic and biaxial rotation stimulation,semi-quantification reported the counts of Fos-labeled neurons in mPFC for treated and control groups were calcuted to be 1053±240.50 vs 44.25±3.64(Galvanic)and 509.80±54.40 vs 128.30±7.66(rotary)per section,respectively.Conclusion:Both biaxial rotation and Galvanic stimulation of vestibular organs could activate neurons in medial prefrontal cortex,implicating mPFC in receiving and processing of vestibular signals.