Li Shuang, Yao Wen-Qing, Tao Ye-Zheng, Ma Lan, Liu Xing
The Pharmacology Research Center, Shanghai Medical College, Fudan University, Shanghai 200032, China.
Sheng Li Xue Bao. 2018 Jun 25;70(3):228-236.
Serotonin (5-hydroxtryptamine, 5-HT), one of the central neurotransmitters, is the most important modulator for emotion regulation, sensory processing, cognitive control, etc. The serotonergic neurons are limited in amount and mainly distributed in the dorsal raphe nucleus (DR) and the median raphe nucleus (MR) in the midline of the brain stem. Previous studies mainly focused on the function of 5-HT neurons in the DR, but little is known about 5-HT neurons in MR. In the present study, with Pet1-Cre transgenic mice and DREADDs technology, we specifically activated or silenced 5-HT neurons in the MR, and aimed to explore their roles in anxiety- and depressive-like behaviors. The results showed that silencing 5-HT neurons in the MR decreased anxiety-like behaviors in the open field and elevated plus maze tasks. Inhibition of 5-HT neurons in the MR decreased depressive-like behaviors in the sucrose preference and forced swim test, while activation of 5-HT neurons in the MR enhanced depressive-like behaviors in the sucrose preference test. These results suggest that the 5-HT neurons in the MR play a key role in regulating anxiety- and depression-like behaviors.
血清素（5-羟色胺，5-HT）是中枢神经递质之一，是情绪调节、感觉处理、认知控制等最重要的调节因子。血清素能神经元数量有限，主要分布在脑干中线的背侧中缝核（DR）和中缝正中核（MR）。以往的研究主要集中在DR中5-HT神经元的功能，但对MR中5-HT神经元了解甚少。在本研究中，我们利用Pet1-Cre转基因小鼠和DREADDs技术，特异性激活或沉默MR中的5-HT神经元，旨在探索它们在焦虑样和抑郁样行为中的作用。结果表明，沉默MR中的5-HT神经元可减少旷场试验和高架十字迷宫试验中的焦虑样行为。抑制MR中的5-HT神经元可减少蔗糖偏好试验和强迫游泳试验中的抑郁样行为，而激活MR中的5-HT神经元则可增强蔗糖偏好试验中的抑郁样行为。这些结果表明，MR中的5-HT神经元在调节焦虑样和抑郁样行为中起关键作用。
