title: An increase in synaptic NMDA receptors in the insular cortex contributes to neuropathic pain.
abstract: Neurons in the insular cortex are activated by acute and chronic pain, and inhibition of neuronal activity in the insular cortex has analgesic effects. We found that in a mouse model in which peripheral nerve injury leads to the development of neuropathic pain, the insular cortex showed changes in synaptic plasticity, which were associated with a long-term increase in the amount of synaptic N-methyl-d-aspartate receptors (NMDARs), but not that of extrasynaptic NMDARs. Activation of cyclic adenosine monophosphate (cAMP)-dependent signaling enhanced the amount of synaptic NMDARs in acutely isolated insular cortical slices and increased the surface localization of NMDARs in cultured cortical neurons. We found that the increase in the amount of NMDARs required phosphorylation of the NMDAR subunit GluN2B at Tyr(1472) by a pathway involving adenylyl cyclase subtype 1 (AC1), protein kinase A (PKA), and Src family kinases. Finally, injecting NMDAR or GluN2B-specific antagonists into the insular cortex reduced behavioral responses to normally nonnoxious stimuli in the mouse model of neuropathic pain. Our results suggest that activity-dependent plasticity takes place in the insular cortex after nerve injury and that inhibiting the increase in NMDAR function may help to prevent or treat neuropathic pain.
authors.affiliation: Center for Neuron and Disease, Frontier Institutes of Life Science and of Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Qiu
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.forename: Kohei
authors.initials: K
authors.lastname: Koga
authors.forename: Yan-yan
authors.initials: YY
authors.lastname: Guo
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.forename: Qian
authors.initials: Q
authors.lastname: Song
authors.forename: Jie-jie
authors.initials: JJ
authors.lastname: Wang
authors.forename: Giannina
authors.initials: G
authors.lastname: Descalzi
authors.forename: Bong-Kiun
authors.initials: BK
authors.lastname: Kaang
authors.forename: Jian-hong
authors.initials: JH
authors.lastname: Luo
authors.forename: Min
authors.initials: M
authors.lastname: Zhuo
authors.forename: Ming-gao
authors.initials: MG
authors.lastname: Zhao
mesh_terms: D000262:Adenylyl Cyclases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism* / Q000473:pathology; D000242:Cyclic AMP / Q000235:genetics / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D009437:Neuralgia / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation / Q000235:genetics; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015290:Second Messenger Systems; D013569:Synapses / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D019061:src-Family Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: C121001:NR2B NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate; D000242:Cyclic AMP; D019061:src-Family Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D000262:Adenylyl Cyclases; C106670:adenylyl cyclase 1