Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Tongzipo Road 172, Changsha, Hunan, 410013, China.
Acta Histochem Cytochem. 2012 Aug 30;45(4):219-25. doi: 10.1267/ahc.12002. Epub 2012 Jun 30.
In visceral pain, anxiety and pain occur simultaneously, but the etiogenesis of this effect is not yet well-described. The anterior cingulate cortex (ACC) is known to be associated with the affective response to noxious stimuli. The aim of the current study is to define the role of ACC extracellular signal-regulated (ERK)-1 and-2 (ERK1/2) activity in the development of pain-related anxiety/depression and the nocifensive response in acetic acid (AA)-elicited visceral pain. The model of visceral pain was created by intraperitoneal (ip) injection of AA to female Kunming mice. We found that AA injection resulted in a dynamic, bilateral ERK1/2 activation pattern in the ACC. Inhibition of ERK1/2 activation 2 hr after AA injection by subcutaneous (sc) injection of the mitogen-activating extracellular kinase (MEK) inhibitor, SL327, had no effect on the nocifensive responses, but did attenuate anxiety-like behavior, as determined by elevated plus-maze and open-field testing results. These data suggest that AA-induced visceral pain activates expression of ACC ERK1/2, which regulates visceral pain-related anxiety, but not the nocifensive response.
在内脏疼痛中，焦虑和疼痛会同时发生，但这种效应的病因尚未得到很好的描述。已知前扣带皮层（ACC）与对有害刺激的情感反应有关。本研究的目的是确定 ACC 细胞外信号调节激酶（ERK）-1 和-2（ERK1/2）活性在乙酸（AA）引起的内脏疼痛相关焦虑/抑郁和伤害性反应发展中的作用。内脏疼痛模型是通过腹腔内（ip）注射 AA 来建立的。我们发现，AA 注射导致 ACC 中 ERK1/2 的动态、双侧激活模式。在 AA 注射后 2 小时，通过皮下（sc）注射丝裂原激活的细胞外激酶（MEK）抑制剂 SL327 抑制 ERK1/2 激活，对伤害性反应没有影响，但减轻了焦虑样行为，这是通过高架十字迷宫和旷场测试结果确定的。这些数据表明，AA 诱导的内脏疼痛激活了 ACC ERK1/2 的表达，调节了内脏疼痛相关的焦虑，但不调节伤害性反应。
