Hanriot Lucie, Camargo Nutabi, Courau Anne Claire, Leger Lucienne, Luppi Pierre Hervé, Peyron Christelle
Centre National de Recherche Scientifique UMR5167, Université de Lyon, Université Lyon1, Institut Fédératif des Neurosciences de Lyon, Lyon, 69372, France.
J Comp Neurol. 2007 Nov 10;505(2):147-57. doi: 10.1002/cne.21482.
Although the main nodes of the neuronal network that regulate paradoxical sleep (PS), also called rapid eye movement sleep, have been identified in rodents, it still needs to be more thoroughly described. We have recently shown that 58% of a hypothalamic neuronal population, the melanin-concentrating hormone (MCH) neurons, are activated after a PS hypersomnia and that MCH, when injected intracerebroventricularly, induces a dose-dependent increase in PS. This suggests that MCH plays a role in PS regulation. Two subpopulations of MCH neurons have been distinguished neurochemically, one that coexpresses cocaine and amphetamine-regulated transcript (CART) and sends ascending projections to the septum and the hippocampus, the other, the non-CART MCH neurons, send descending projections to the lower brainstem and the spinal cord. In order to better characterize the PS-activated MCH neurons it is interesting to determine whether they belong to the first, the second, or both subgroups. We therefore undertook an MCH, CART, and Fos triple immunolabeling study in PS hypersomniac rats. We showed that the MCH neurons activated during PS are part of both subpopulations since we found CART and non-CART MCH-activated neurons. Based on these results and the literature, we propose that MCH could be involved in memory processes and in the inhibition of muscle tone during PS.
尽管调节异相睡眠（PS）（也称为快速眼动睡眠）的神经网络的主要节点已在啮齿动物中得到确认，但仍需更全面地描述。我们最近发现，下丘脑神经元群体中58%的促黑素细胞激素（MCH）神经元在PS睡眠过多后被激活，并且当脑室内注射MCH时，会引起PS剂量依赖性增加。这表明MCH在PS调节中发挥作用。已通过神经化学方法区分出MCH神经元的两个亚群，一个亚群共表达可卡因和苯丙胺调节转录物（CART），并向隔区和海马体发出上行投射，另一个亚群，即非CART MCH神经元，向下脑桥和脊髓发出下行投射。为了更好地表征PS激活的MCH神经元，确定它们属于第一个亚群、第二个亚群还是两个亚群都属于是很有意思的。因此，我们对PS睡眠过多的大鼠进行了MCH、CART和Fos三重免疫标记研究。我们发现，PS期间激活的MCH神经元属于两个亚群，因为我们发现了CART和非CART MCH激活的神经元。基于这些结果和文献，我们提出MCH可能参与记忆过程以及PS期间肌肉张力的抑制。
