NMDA receptors in the anterior cingulate cortex mediate pain-related aversion

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• 作者：Lei ; Liu-Gen ; Sun ; Shan ; Gao ; Yong-Jing ; Zhao ; Zhi-Qi ; Zhang ; Yu-Qiu
• 关键词：Pain-related aversion ; CPA ; NMDA receptors ; AMPA/KA receptors ; Intracerebroventricular injection ; Fos ; ACC ; Rat
• 刊名：Experimental Neurology
• 出版年：2004
• 出版时间：October, 2004
• 年：2004
• 卷：189
• 期：2
• 页码：413-421
• 全文大小：384 K

文摘

Using a rat formalin-induced conditioned place avoidance (F-CPA) model and Fos immunohistochemistry, the present study observed the effect of N-methyl-d-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-isoxozole propionic acid/kainite (AMPA/KA) receptors on pain-related aversion. Adult Sprague–Dawley rats were implanted with cannula in the anterior cingulate cortex (ACC) or the lateral ventricle. Before (10 min) the injection of formalin into a hindpaw on days 2 and 4 of place-conditioning trials, vehicle (0.01 M PBS), the NMDA receptors antagonist, 2-amino-5-phosphonovalerate (AP5), or the AMPA/KA receptors antagonist, 6,7-dinitroquinoxaline-2,3-dione (DNQX), was injected through the cannula. F-CPA was effectively eliminated by both intracerebroventricular (icv) and intra-ACC microinjection of AP5. In contrast, the intra-ACC or icv injection of DNQX failed to alter the conditioning scores of F-CPA compared with vehicle control group (P > 0.05). Intra-ACC or icv injection of AP5 or DNQX had no effect on formalin-induced acute nociceptive behaviors. Fos immunoreactivity in the ACC was activated by retrieval of pain-related aversion, and this activation was significantly suppressed by preadministration of AP5, but not DNQX (P < 0.001). These results suggest that NMDA receptors in the ACC are preferentially involved in the processing of the affective dimension of pain.