Study On Brain Functional Connection Patterns Of Rhesus Monkey With Brain-Degeneration Model Induced By Methanol

The clinical manifestations of patients with neurodegenerative diseases are usually associated with related degenerative brain regions.The general clinical symptoms of the disease include dementia which is common symptom or/and dyskinesia.Patients with symptoms of dementia usually present with cognitive intelligence decline,including memory,learning,language,digital skills,visual spatial perception,and deductive reasoning.Recent studies have shown that the functional integration of the three major functional networks in the brain(default mode network(DMN),central execution network(CEN),salience network(SN))are significantly related to cognition and the integration changes among them may be involved in the pathological process of neurodegenerative diseases.These patients often show a marked decline in memory function.Moreover the functional integration of memory-related networks in degenerative diseases is also helpful in understanding the pathological mechanisms of such diseases.Therefore,this study aims to reveal the physiological and pathological mechanisms of brain degenerative diseases by using functional magnetic resonance imaging(MRI)based the functional connectivity(FC)of brain function degeneration in cognitive and memory two aspects.Therefore,this study aims to reveal the physiological and pathological mechanism of brain degenerative disease by using rest-state FC.In this research,9 male macaques with brain degeneration induced by methanol were selected as the experimental group,and 10 age-matched healthy male macaques were selected as the control group.All macaques data were obtained from resting state functional magnetic resonance imaging(fMRI).First,for cognitive-related networks,we built DMN,CEN,SN using seed-based FC analysis,then we evaluated the FC characteristics of these networks.Subsequently,we compared the differences of the three functional networks between the two groups of macaque.Compared with the control group,the experimental group showed,increased FC between the posterior cingulate gyrus and the right primary motor cortex,decreased FC between the posterior cingulate gyrus and the right pole of temporal cortex,the right posterior insula.In CEN,the enhanced FC between the dorsolateral prefrontal lobe and the left secondary auditory cortex,the left anterior cingulate gyrus,the right inferior temporal cortex,the right visual area 1,the reduced FC showed between the dorsolateral prefrontal lobe and the left ventral temporal cortex,the left visual area 1,right superior temporal cortex.In the SN,the FC is enhanced between the right dorsal anterior insula and the right visual anterior cortex-dorsal part,right visual area 1.The increased FC between the right ventral anterior insula and the left visual area 1,the reduced FC between the right ventral anterior insula and the right primary motor cortex,the double pole of temporal cortex.These results suggest an abnormality of information interaction among the three cognitive-related networks and the primary perceptual-motor networks.Next,from the perspective of brain degeneration leading to memory decline,we divided the hippocampus into two anterior and posterior hippocampus sub-regions,and carefully constructed and analyzed the memory-related functional network of macaques.Our results are consistent with previous findings and we found that the functional differentiation of the macaques before and after the hippocampus is clearly separated from the FC pattern of the whole brain.Subsequently,we further explored the memory-related network function abnormalities of macaques induced by methanol.The results showed that there were significant differences in the memory network constructed by the right hippocampal area and the left posterior hippocampus as the seed points.These differential areas mainly involve the frontal lobe,temporal lobe,visual cortex,and secondary somatosensory cortex.This result indicates that hippocampal FC abnormalities in neurodegenerative diseases involve multiple brain regions,including involving advanced cognitive systems,as well as primary sensory systems.The combined effect of them may be related to the changes in degenerative memory function.In general,the male macaques with methanol-induced brain degeneration were studied in this study.By using the FC analysis method,it was found that brain degeneration would affect the connectivity of brain cognitive and memory-related functional networks,which help us to understand the physiological and pathological mechanisms of brain degenerative diseases.