Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China.
Department of Rehabilitation Medicine, Suining Central Hospital, Suining, 629000, China.
Behav Brain Res. 2021 Aug 6;411:113388. doi: 10.1016/j.bbr.2021.113388. Epub 2021 May 27.
Itch is an unpleasant sensation that evokes a desire to scratch. Itch processing in the peripheral and spinal cord has been studied extensively, but the mechanism of itch in the central nervous system is still unclear. Anterior cingulate cortex (ACC) and prelimbic cortex (Prl), two subregions of the prefrontal cortex closely related to emotion and motivation, have been reported to be activated during itching in a series of functional imaging studies. However, the exact role of Prl and the differences between ACC and Prl in itch modulation remains unknown. To directly test the differential roles of ACC and Prl in itch processing, we chemogeneticlly inhibited the caudal ACC and Prl, respectively. We found that inhibition of caudal ACC reduced histaminergic but not non-histaminergic itch-induced scratching behaviors. In contrast, inhibition of Prl reduced both histaminergic and non-histaminergic itch-induced scratching behaviors. Our study provided direct evidence of Prl involvement in itch modulation and revealed the differential roles of caudal ACC and Prl in regulating histaminergic and non-histaminergic itch.
痒是一种不愉快的感觉，会引起搔抓的欲望。外周和脊髓的痒觉处理已经得到了广泛的研究，但中枢神经系统的痒觉机制仍不清楚。在前扣带皮层（ACC）和前额叶皮层的两个亚区，前扣带皮层（ACC）和前额叶皮层的两个亚区，与情绪和动机密切相关，在一系列功能成像研究中报告说在瘙痒时被激活。然而，Prl 的确切作用以及 ACC 和 Prl 在痒觉调制中的差异仍不清楚。为了直接测试 ACC 和 Prl 在痒觉处理中的差异作用，我们分别化学遗传抑制尾侧 ACC 和 Prl。我们发现，抑制尾侧 ACC 减少了组氨酸能但不减少非组氨酸能引起的搔抓行为。相比之下，抑制 Prl 减少了组氨酸能和非组氨酸能引起的搔抓行为。我们的研究提供了 Prl 参与痒觉调制的直接证据，并揭示了尾侧 ACC 和 Prl 在调节组氨酸能和非组氨酸能痒觉中的差异作用。
