酪氨酸羟化酶阳性神经元在扬子鳄、家鸡及大鼠脑桥的分布比较

Comparative study on the distribution of TH positive neurons in the pons of alligator sinensis,domestic chickens and rats

目的:观察并比较扬子鳄、家鸡及大鼠脑桥酪氨酸羟化酶(Tyrosine hydroxylase,TH)阳性神经元的形态和分布,为生物进化及扬子鳄种群遗传保护与神经系统疾病防治提供比较解剖学资料。方法:扬子鳄6只、家鸡和SD大鼠各15只。三种动物再各分三组进行分次实验,每次扬子鳄2只,家鸡和SD大鼠各5只,同一时间内电击处死后,取脑桥组织,采用免疫组织化学方法结合黑马病理图像分析系统检测三种动物脑桥TH阳性神经元的分布特征。结果:三种动物脑桥均见TH阳性神经元成团或散在分布,均可见椭圆形、圆形、梭形、多角形等,但三种动物间脑桥不同形态的细胞数量大多存在差异(P<0.01);三种动物脑桥TH阳性神经元均以中、小细胞为主,大细胞相对较少;与扬子鳄相比,家鸡及大鼠脑桥同节段TH阳性神经元数均明显增加,灰度值降低,均具有统计学差异(P<0.01);与家鸡相比,大鼠脑桥TH阳性神经元数明显增加,灰度值降低,均具有统计学差异(P<0.01)。结论:扬子鳄、家鸡及大鼠脑桥TH神经元数量依次增多,细胞平均灰度值依次降低,不同形态的细胞比例存在一定差异,提示脑桥TH神经元的分布差异可能与不同物种脑桥执行其相关神经系统生理功能的不同有关。

AIM： To observe and compare the anatomic distribution of tyrosine hydroxylase （TH）-positive neurons in the pons of alligator sinesis/Chinese alligator, domestic chickens and rats for collecting the comparative anatomy data for investigation of the biological evolution and population protection of Chinese alligator. METHODS： Totally, Chinese alligators （n=6）, domestic chicken （n = 15） and Sprague-Dawley （SD） rats （n= 15） of either sex were included and cross-grouped into three groups with 2 alligators, 5 chicken and 5 rats for each. Animals in the three groups were simultaneously sacrificed by electric shock. The expressions of TH in pons were detected by immuno-histochemical assay and HemaGSM 2000P analysis. RESULTS： Conglomerated or diffused distribution of the TH positive neurons were commonly seen in pons in alligator sinesis, domestic chicken and rats. The TH positive cells presented with diverse cellular morphology by shapes of oval, roundness, spindle or polygon, whereas the cell number in different morphology varied a lot in pons among the three animals（P〈0.01）. The TH reactive neurons were primarily middle-sized or small-sized animals, and in the pons in large-sized cells low number. Nevertheless, the three kinds of were in relatively significantly increased reactive neurons to TH was seen in corresponding segments of the pons from chickens and rat as compared with alligator sinesis （P〈 0.01）, and the gray value was also reduced evidently （P〈0.01）. In addition, the TH positive neurons in the pons of rats were increased greatly, but decreased significantly in gray value, when compared with the chicken＇s（P〈0.01）. CONCLUSION. The TH positive neurons were increased in turn in the pons of the Chinese alligators, domestic chickens and rats, the average gray value for the cells were decreased ordinally, and the number for diverse cellular morphology were not proportional. These findings suggest that TH distribution differences may be associated with different species of function area carries out its related nervous systems function in the pons.