Morphological Study On Bactrican Camel (Camelus Bactrianus) Brain Using Stereology And MRI

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.