Yadav Vijay K, Karsenty Gerard
Department of Genetics and Development, Columbia University Medical Centre, New York, NY 10032, USA.
Aging (Albany NY). 2009 Nov 5;1(11):954-6. doi: 10.18632/aging.100100.
The adipocyte-derived hormone leptin inhibits appetite and bone mass accrual. To fulfill these two functions leptin requires the integrity of hypothalamic neurons but not the expression of its receptor, ObRb on these neurons. These results suggested that leptin acts first elsewhere in the brain to mediate these functions. However, this neuroanatomical site of leptin action in the brain remained elusive. Recent mouse genetic, electrophysiological and neuroanatomical studies provide evidence that leptin inhibits appetite and bone mass accrual through a two-step pathway: it decreases synthesis and the release by brainstem neurons of serotonin that in turn targets hypothalamic neurons to regulate appetite and bone mass accrual.
脂肪细胞分泌的激素瘦素可抑制食欲并减少骨质累积。为实现这两种功能，瘦素需要下丘脑神经元的完整性，但并不依赖于这些神经元上其受体ObRb的表达。这些结果表明，瘦素首先在大脑的其他部位发挥作用来介导这些功能。然而，瘦素在大脑中的这个神经解剖学作用位点仍然难以捉摸。最近的小鼠遗传学、电生理学和神经解剖学研究提供了证据，表明瘦素通过一个两步途径抑制食欲和减少骨质累积：它减少脑干神经元中血清素的合成和释放，而血清素反过来作用于下丘脑神经元以调节食欲和骨质累积。
