Plastic Brain Functional Changes At Acute Stage In Rodent Amputation Model

Most amputees suffer sequelae such as stump sensation,stump pain,phantom limb sensation and phantom limb pain.Amputation leads to the loss of sensation input and causes functional changes in the central neural system.Such changes in the brain are believed to be the pathogenesis of amputation sequelae.Studies on the brain plasticity of amputated animal will offer more information about the mechanism of brain plasticity.Brain plasticity after amputation manifests the short-term changes related to the unmasking of latent synapses as well as the long-term reorganization due to the sprouting of new synaptic connections.There is a lack of research on the short-term plasticity changes after amputation.While the short-term plastic change was thought to be related with long-term symptoms in amputees,researches on the short-term functional changes offer more information on the mechanisms of brain plasticity after amputation.The cerebral blood flow(CBF)change serves as an important biomarker of the brain plastic functional reorganization.Using laser speckle contrast imaging(LSCI),we performed a longitudinal study on forelimb amputation to unveil the plastic brain functional changes in rodent model,particularly along the intact pathway.Our results showed that the CBF under electrical stimulation to the intact forepaw increased significantly as late as 9 hours after amputation at acute stage.While at chronic stage(>14days),CBF showed the similar pattern to control group.Our results showed the dynamic plasticity of brain functional response along the intact sensory pathway at different stages after amputation and indicated that plastic changes occurred within acute stage,not immediately but as late at 9h after amputation.