Behavioral responses and Fos activation following orofacial formalin injection in a rodent model of Parkinson's disease

研究了单侧或双侧前脑内侧束注射6-羟多巴胺对帕金森病（PD）模型大鼠口面区伤害性刺激的调节作用。探讨了上唇注射福尔马林后大鼠的行为反应及三叉神经脊髓尾侧亚核（Vc） c-Fos和pERK的表达。当同侧注射福尔马林到病变处时，单侧PD大鼠表现出增加的伤害反应。这种过敏反应与Vc中c-Fos表达增加有关。6-OHDA损伤对侧注射福尔马林后，6-OHDA大鼠的行为反应降低。而pERK在Vc中的表达没有变化。虽然双侧PD大鼠未观察到过敏反应，但Vc中c-Fos表达增加。这些结果表明，6-羟色胺的减少引起了对来自口面部区域的伤害性刺激的过敏反应。

We investigated the modulation of the nociceptive stimuli from the orofacial region in Parkinson's disease (PD) model rats, which were produced by the unilateral or bilateral injection of 6-OHDA into the medial forebrain bundle. Behavioral responses to formalin injection into the upper lip and the expression of c-Fos and pERK in trigeminal spinal subnucleus caudalis (Vc) were explored.Unilateral PD rats showed increased nociceptive responses when formalin was injected ipsilaterally to the lesion. This hyperalgesic response was associated with increased c-Fos expression in Vc. When formalin was injected into contralateral side to 6-OHDA lesion, behavioral responses were reduced in 6-OHDA rats. However, the expression of pERK in Vc remained unchanged. Although the hyperalgesic response was not observed in bilateral PD rats, c-Fos expression in Vc increased.These results suggest that 6-OHDA resion causes hyperalgesic response to nociceptive stimulation from the orofacial region.