Department of Physiology, Wakayama Medical University, Kimiidera 811-1, Wakayama City, 641-8509, Japan.
Brain Res. 2010 May 6;1329:103-12. doi: 10.1016/j.brainres.2010.03.006. Epub 2010 Mar 11.
In the present study we examined whether the descending facilitation from the rostral ventromedial medulla (RVM) is required for the enhancement of formalin-evoked nocifensive behavior following repeated forced swim stress. Rats were subjected to forced or sham swim stress for 3days. Withdrawal latency to noxious thermal stimuli and mechanical withdrawal threshold to von Frey filaments did not change significantly in both groups at 24h after the last stress session. The forced swim stress showed significantly enhanced nocifensive behavior to the subcutaneous administration of formalin at 2days after the last stress session (1330.1+/-62.8s), compared to the sham swim (1076+/-102.4s, p<0.05) and naive groups (825.9+/-83.2s, p<0.01). The destruction of the RVM with ibotenic acid led to prevent the enhancement of formalin-evoked nocifensive behavior in the forced swim group. These findings suggest that the descending facilitation from the RVM may be involved in the enhancement of formalin-evoked nocifensive behavior following the forced swim stress.
在本研究中，我们考察了在重复强迫游泳应激后，来自延髓头端腹内侧区（RVM）的下行易化是否是增强福尔马林诱发的伤害性行为所必需的。大鼠连续 3 天接受强迫游泳或假游泳应激。末次应激后 24 小时，两组大鼠的热刺激回避潜伏期和 von Frey 纤维机械缩足阈值均无明显变化。与假游泳组（1076+/-102.4s，p<0.05）和未处理组（825.9+/-83.2s，p<0.01）相比，末次应激后 2 天，强迫游泳组对福尔马林皮下给药的伤害性行为明显增强（1330.1+/-62.8s）。红藻氨酸损毁 RVM 可防止强迫游泳组福尔马林诱发的伤害性行为增强。这些发现表明，来自 RVM 的下行易化可能参与了强迫游泳应激后福尔马林诱发的伤害性行为的增强。
