Tractography-based Parcellation And Anatomical Connectivity Of Macaque Superior Temporal Region

Exploring brain connectivity is fundamental to understanding the functional structure of the cerebral cortex,for example,neurons from the visual and auditory cortex have similar anatomical and organizational structures,but they support different functions and show distinct differences in anatomical connections with the rest of the brain.Differences in these connections may explain their functional specificity.In the last two decades,diffusion Magnetic Resonance Imaging(dMRI)has been widely used to study the brain's microscopic structure and connectivity,as well as abnormalities and Alzheimer's Disease caused by pathological factors such as multiple sclerosis.Specifically,Diffusion Tensor Imaging(DTI),which uses Gaussian ellipsoids to model the Diffusion rates of water molecules in each electroencephalograph,provides quantitative information about the microstructure embedded in each electroencephalograph.Then,the Tractography algorithm is applied to dMRI data to display and visualize the fiber track of white matter.The biological validity of dMRI data modeling remains a key challenge in the study of the normal brain and its dysfunction.People have long tried to divide the brain into brain maps based on microstructures,macroscopic structures,or regions that connect features.Connectivity based segmentation is getting more and more attention,especially in the past two decades,multimodal magnetic resonance imaging technology has made great progress.Brain atlas is an important tool for brain imaging data analysis.In recent years,it has been extensively studied.According to different drawing standards,several versions of brain atlas have been constructed.These criteria consists of features of cellular structure,distribution of neurotransmitter receptors,myelin fingerprints,transcriptional histochemical patterns and features of structural and functional connectivity.Among them,the brainnetome atlas is closely related to the information of the brain connectome,which is formed by the segmentation of the brain based on the anatomical connectivity profiles derived from the structural neuroimaging data.At present,the research of constructing monkey brain map by diffusion tensor imaging is very limited.In addition,as a non-human primate model,macaques are often used to simulate the structure and function of the human brain,and widely used in studying the brain neurological mechanisms of the development,cognitive functions,and psychiatric disorders.The monkey brain's voice recognition mechanism is very similar to that of the human brain.Evolutionarily speaking,it belongs to the homologous brain region of human language,both based on the superior temporal gyrus,which has speech processing function.On account of the complex pattern of temporal lobe information processing,we think there are more subtle subregion patterns in the superior temporal gyrus.In addition,the early monkey brain map based on cellular structure does not specify the brain regions.In this study,we used DTI data from the brains of 8 living macaques and the probabilistic fiber tracking method of diffusion tensor imaging to divide the brains of living macaques into different regions.In this study,a detailed map of the superior temporal gyrus of nonhuman primates was constructed based on the anatomical connection pattern,which will provide a basis for the subsequent study of functional patterns.