牦牛颈上神经节对其生境适应的形态学机制

本研究旨在研究牦牛颈上神经节(SCG)对其生境适应的形态学特征,以探讨高原动物交感神经系统对青藏高原生态环境适应的形态学机制.运用常规HE及尼氏染色法,并采用形态计量学和SPSS16.0统计软件,对成年牦牛和黄牛SCG的形态学特征进行比较研究.结果表明:牦牛SCG的长、宽和厚度均显著地小于黄牛的相应数据(P＜0.01)；牦牛的SCG主要由表面被膜、神经节单元、神经纤维、血管及结缔组织组成,被膜较黄牛的薄,结缔组织所占比例较黄牛的少,但节内组织较黄牛的致密；牦牛的神经节单元主要包含神经节细胞、卫星细胞、成纤维细胞、毛细血管和神经纤维,该组成特征与黄牛的相似；其神经节单元单个视野内节细胞、卫星细胞及成纤维等细胞与黄牛的基本相同(P=1),但牦牛节细胞间的神经纤维较黄牛的少,而血管数显著多于黄牛的(P＜0.01)；牦牛SCG的头部以神经节单元为主,尾部以神经纤维为主,其特征与黄牛的相似.结果提示,在青藏高原高寒、低氧的极端生态环境中,牦牛在半放野、全年放牧的状态下,其SCG经长期进化形成了体积较小,神经节细胞、卫星细胞及其细胞间神经纤维较少,但血管十分丰富等形态学特征以适应极端生境.

Morphological Mechanism of the Superior Cervical Ganglion in the Yak (Bos grunniens) Adapting to Its Habitat

This experiment was conducted to study the morphological adaptations of the superior cervical ganglion(SCG) of the yak to its habitat as well as investigate the adaptive mechanism of sympathetic nervous system to the Qinghai-Tibet plateau in plateau animals.The morphological characteristic of SCG of the yak was compared and analyzed with the cattle by morphometry method and SPSS16.0 software with HE and Toluidine Blue stained section.The results showed that: 1) The length,width and thickness of SCG of the yak were smaller than cattle significantly(P<0.01);2) The SCG of yak were consisted with capsule,ganglion units,neuropil,vessel and connective tissue;Compared with cattle,yak has a thinner capsule and smaller proportion of connective tissue,while tissue in ganglion was more dense;3) In both yak and cattle,the ganglion units was consisted with ganglion cell,satellite cell,fibroblasts,capillary and neuropil,while attractive characteristic was that the number of ganglion cells,satellite cells and neuropil in unit visual field of the ganglion units of the yak were similar to the cattle(P=1),but the number of the yak’s capillary were more than that of the cattle(P<0.01);4) Similar to cattle,the head of SCG was mainly composed with ganglion units and tail was mainly nerve fibers in yak.These results indicated that as a year-round grazing and half wild animal,yak living in the Qinghai-Tibetan Plateau and its SCG have evolved with some morphological characteristics such as small volume,less ganglion cells and nerve fiber,and rich vessel and so on,that enabling them to adapt the ecotope well.