Reports of brown-like adipocytes in traditionally white adipose tissue (WAT) depots occurred ~30 years ago, but interest in white adipocyte ‘browning’ only has gained attention more recently. We integrate some of what is known about the sympathetic nervous system (SNS) innervation of WAT and brown adipose tissue (BAT) with the few studies focusing on the sympathetic innervation of the so-called ‘brite’ or ‘beige’ adipocytes that appear when WAT sympathetic drive increases (for example, cold exposure and food deprivation). Only one brain site, the dorsomedial hypothalamic nucleus (DMH), selectively browns some (inguinal WAT (IWAT) and dorsomedial subcutaneous WAT), but not all WAT depots and only when DMH neuropeptide Y gene expression is knocked down, a browning effect is mediated by WAT SNS innervation. Other studies show that WAT sympathetic fiber density is correlated with the number of brown-like adipocytes (multilocular lipid droplets, uncoupling protein-1 immunoreactivity) at both warm and cold ambient temperatures. WAT and BAT have sensory innervation, the latter important for acute BAT cold-induced temperature increases, therefore suggesting the possible importance of sensory neural feedback from brite/beige cells for heat production. Only one report shows browned WAT capable of producing heat in vivo. Collectively, increases in WAT sympathetic drive and the phenotype of these stimulated adipocytes seems critical for the production of new and/or transdifferentiation of white to brite/beige adipocytes. Selective harnessing of WAT SNS drive to produce browning or selective browning independent of the SNS to counter increases in adiposity by increasing expenditure appears to be extremely challenging.

在传统的白色脂肪组织（WAT）库中出现类似褐色脂肪细胞的报道大约在30年前，但是对白色脂肪细胞“变褐”的兴趣直到最近才引起关注。我们将有关WAT和棕色脂肪组织（BAT）的交感神经系统（SNS）神经支配的一些已知知识与少数研究集中于所谓的“ brite”或“米色”脂肪细胞的交感神经支配的研究相结合。 WAT的同情驱动力增加（例如，冷暴露和食物匮乏）。只有一个大脑部位，即下丘脑下丘脑核（DMH），选择性地使一些（腹膜内WAT（IWAT）和背部皮下WAT）褐变，但并非所有WAT库都褐变，并且只有当DMH神经肽Y基因表达被敲低时，才介导褐变作用由WAT SNS支配。其他研究表明，在温暖和寒冷的环境温度下，WAT交感神经纤维密度都与棕色样脂肪细胞（多眼脂质滴，解偶联蛋白1免疫反应性）的数量相关。WAT和BAT具有感觉神经，后者对于BAT低温引起的急性温度升高很重要，因此表明来自英国/米色细胞的感觉神经反馈对于产热的重要性。只有一份报告显示褐褐色的WAT能够产生热量 因此，暗示来自英国/米色细胞的感觉神经反馈对于产热的可能重要性。只有一份报告显示褐褐色的WAT能够产生热量 因此提示来自英国/米色细胞的感觉神经反馈对于产热的可能重要性。只有一份报告显示褐褐色的WAT能够产生热量体内。总的来说，WAT交感驱动力的增加和这些受刺激的脂肪细胞的表型对于白色到英国/米色脂肪细胞的新的和/或转分化的产生似乎至关重要。选择性利用WAT SNS驱动产生褐变或独立于SNS进行选择性褐变以抵消通过增加支出来增加肥胖的现象似乎极具挑战性。