【作者】 谢朝晖；

【导师】 王建林；

【作者基本信息】 兰州大学 ， 动物学， 2008， 博士

【摘要】 通过对双峰驼(Camelus bactrianus)大脑形态学测量、MR图像分析、体视学研究和与其它偶蹄动物大脑的比较解剖学研究,结果表明,双峰驼大脑的沟回方式特别,颞叶和嗅球发达,成年双峰驼平均脑重568.3g,大脑与体重的比例约1/700～1/800;小脑占整个大脑9.84%;横径指数为0.599;Pilleri指数为0.163,其“头部集中程度”较小;双峰驼脑商约为1.11,处理和利用复杂信息的能力趋于中等,说明双峰驼在特殊环境下,大脑在漫长的进化过程中定向选择的结果。运用设计依赖体视学即卡瓦列原理和垂直截面,可对三维结构的二维截面图像的测量来研究三维结构本身的定量特征。对成年双峰驼固定大脑的体积、皮层体积、皮层表面积和厚度分别进行测试,其结果为446 cm~3、222 cm~3、1264 cm~2和2.3 mm。大脑1/3的皮层隐藏在脑沟之中,大脑左右半球无显著的偏侧性(P＞0.05)。平均小脑重42 g,体积为38 cm~3,皮层表面积为396 cm~2,约70%的皮层隐藏在小脑裂中。左、右大脑半球的形状因子分别为71.8 cm~3/cm~3和70.9 cm~3/cm~3;小脑左、右半球的形状因子分别为149.5 cm~3/cm~3和152.9 cm~3/cm~3,意味着小脑卷曲程度较高,但不存在偏侧性(P＞0.05)。脑组织的发育除遗传因素和行为因素外,同时也受动物营养条件、性别差异、体重、年龄等因素的影响。基于成年双峰驼固定大脑MRI数据分析对其体积、表面积和等周比率(IPR)等在冠状、矢状、水平切面上测试,组内相关系数评价重复测量可靠性较好。双峰驼大脑的平均体积为336 cm~3,表面积为901 cm~2、IPR为18.6。大脑固定后,其收缩指数约为25%。此方法运用体视学MRI软件对动物活体大脑形态学准确定量研究在神经发育生物学、病理诊断、动物大脑数字化构建等方面迅捷有效。更多还原

【Abstract】 To investigate the brain of Bactrican camel(Camelus bactrianus)by morphological measure,analysis of MR image,stereological approach and comparative anatomy study with some artiodactyls.The results showed that of many features included its special sulci or fissural pattern of the cerebral hemispheres, well-developed temporal lobe and olfactory bulb.The mean values of the adult Bactrian camel 568.3g.Compared to body size,Bactrian camel is 1/700～1/800. Cerebellar weight averages 9.84%of brain.The diametric index is 0.599 and Pilleri index 0.163.It suggested that Bactrian camel is less "cephalized".The EQ is about 1.11,which showed that the moderate degree ability to process and utilize complex information.The results may reflect selective pressures in adapting to a particular environmental niche over a protracted period of evolution.Design-based stereological methods(the Cavalieri principle and vertical sectioning),that provide a three-dimensional interpretation of structures based on observations,made on two-dimensional sections.To estimate volumes,cortical surface volumes and areas and thickness of cortical surface in fixed adult Bactrian camel brains respectively,the results are 446 cm~3,222cm~2,1264 cm~2 and 2.3mm. One thirds of this surface was hidden within sulci.The differences between leftright hemispheres and cerebellar halves did not show statistical significance (P＞0.05).The cerebellum occupied 38 cm~3 with a cortical surface of 396 cm~2 of which roughly 70%was hidden in fissures.The shape factors of right and left cerebral hemispheres are average 71.8 cm~3/cm~3 and 70.9 cm~3/cm~3 and the half-cerebellar are 149.5cm~3/cm~3 and 152.9 cm~3/cm~3.Using the appropriate shape factors,apparently right-left hemispheres were highly convoluted and not significantly different as well as cerebellum(P＞0.05).The brain of histological development are influenced not only by the genetic factors and behavior but this could be due to one or more reasons related to bread,sex difference,body weight,and developmental age,etc. Magnetic Resonance Imaging(MRI)-based morphometric analysis of volumes, surface areas and isoperimetric ratio(IPR)in the fixed adult Bactrican camel brain is based upon the coronal,sagittal and horizontal segmentation and parcellation of MRI data.The reliability of stereological estimates and the intraclass correlation coefficient (ICC)indicated an excellent level of agreement.The average value of volume was 336cm~3,for surface area 901cm~2 and for IPR 18.6.The shrinkage index of brain is about 25%after fixed.Using stereological MRI software,this protocol provides an efficient and accurate quantitative investigation in vivo of developmental neurology, pathological diagnosis and digital brain in animal for future study.更多还原