Study On The Changes Of White Matter Function In Brain Induced By Cold Pain Stimulation

Pain has always been an unavoidable health problem of human beings,which seriously affects the quality of their life.Studies have shown that pain not only causes negative emotions in patients,but also affects the brain’s sensory transmission pathways and motor executive function.Most studies are based on gray matter changes to explore the brain’s processing of pain,while the changes in white matter areas are yet to be studied.Therefore,based on the levels of voxel and network,this study focuses on whether the white matter function of people with different pain tolerance was changed,and whether the change was related to the regulation of pain by the descending pain modulation system or the generation of anxiety.Firstly,this study investigated the functional changes of white matter in response to cold pain at the voxel-wise level.By calculating voxel-mirrored homotopic connectivity(VMHC)of subjects’ brains,we see some interesting results.Through comparative analysis,it is found that the pain-related dysfunction of the superficial-superior corona radiata and the superficial-corticospinal tract may inhibit the input of pain information through the thalamus related circuits.The superior longitudinal fasciculus and the superficial-corticospinal tract are related to the frontal lobe and cerebellum,respectively.Therefore,it is speculated that the functional changes of the superior longitudinal fasciculus and the superficial-corticospinal tract may cause the automatic avoidance of pain and motor dysfunction.In addition,the functional changes of the superior longitudinal fasciculus and the superficial-uncinate fasciculus related to the frontal lobe may also be the result of the functional specificity of the descending pain modulation system involved in the default mode network(DMN).The second part,the functional changes of brain white matter under cold pain stimulation are studied from the network level.K-means clustering was used to obtain different white matter functional networks,and functional connectivity(FC)between networks was studied.The changes of FC between the posterior cerebellar network and sensorimotor cortex(SMC)may be the result of the effective regulation of human pain perception by the descending pain modulation system.The posterior cerebellar and frontotemporal regions are the key regions of DMN,and their connectivity changes could be explained by the need to weaken the self-referential connections of the brain to regulate the external pain stimulus more effectively.In addition,the superior temporal network and the precentral and postcentral gyrus network are also important brain regions for processing perceptual information,and their functional specificity may be related to the tolerance of pain-sensitive people to pain stimulation.The results of the above two parts of the study found functional changes in white matter regions and white matter networks during pain processing,revealing the important regulatory role of the descending pain modulation system in pain information during continuous cold pain stimulation.The whole process involves the reception and transmission of pain signals in the thalamo-cortical circuit,pain avoidance and motor executive functions related to the cerebellum and corticospinal tract,the regulation of external pain stimuli by the DMN network,and the processing of negative emotions.The ideas and conclusions of this study will help future research to more deeply explore the changes of white matter function under pain,which also has important auxiliary value for the treatment of pain-related diseases in clinical practice,and provides a strong basis for improving anxiety and other negative emotions caused by pain.