Mechanism underlying the anterior insula and its related neural pathway involved in the transmission and modulation of pain

摘要

In recent years,the role of insular cortex(IC)in pain sensation gains more and more attention.Based on its anatomical connection feature,i is generally conceived that anterior insula(aIC)is involved in emotional aspectand posterior insula(pIC)is related to sensory aspect of pain,respectively.However,functional evidence is still lacking to support this hypothesis.In addition,the neural pathway transmitting emotional pain sensation to IC is unknown.The main results of the present study are as follows:①Fos immunostaining data showed that all IC subregions are activated under the condition of neuropathic pain.Chemogenetically activating aIC elicits mechanical pain and anxiety while activating pIC only elicits mechanical pain but without anxiety in naive mice.The facilitatory role of IC in pain and anxiety is mediated by pyramidal neurons,while GABAergic neurons exert opposite effects.