Wiedmann Nicole M, Stefanidis Aneta, Oldfield Brian J
Department of Physiology, Monash University, Clayton, Victoria, Australia.
Department of Physiology, Monash University, Clayton, Victoria, Australia
FASEB J. 2017 Nov;31(11):4879-4890. doi: 10.1096/fj.201700433R. Epub 2017 Aug 10.
The functional recruitment of classic brown adipose tissue (BAT) and inducible brown-like or beige fat is, to a large extent, dependent on intact sympathetic neural input. Whereas the central neural circuits directed specifically to BAT or white adipose tissue (WAT) are well established, there is only a developing insight into the nature of neural inputs common to both fat types. Moreover, there is no clear view of the specific central and peripheral innervation of the browned component of WAT: beige fat. The objective of the present study is to examine the neural input to both BAT and WAT in the same animal and, by exposing different cohorts of rats to either thermoneutral or cold conditions, define changes in central neural organization that will ensure that beige fat is appropriately recruited and modulated after browning of inguinal WAT (iWAT). At thermoneutrality, injection of the neurotropic (pseudorabies) viruses into BAT and WAT demonstrates that there are dedicated axonal projections, as well as collateral axonal branches of command neurons projecting to both types of fat. After cold exposure, central neural circuits directed to iWAT showed evidence of reorganization with a greater representation of command neurons projecting to both brown and beiged WAT in hypothalamic (paraventricular nucleus and lateral hypothalamus) and brainstem (raphe pallidus and locus coeruleus) sites. This shift was driven by a greater number of supraspinal neurons projecting to iWAT under cold conditions. These data provide evidence for a reorganization of the nervous system at the level of neural connectivity following browning of WAT.-Wiedmann, N. M., Stefanidis, A., Oldfield, B. J. Characterization of the central neural projections to brown, white, and beige adipose tissue.
经典棕色脂肪组织（BAT）以及可诱导产生的棕色样脂肪或米色脂肪的功能性募集在很大程度上依赖于完整的交感神经输入。虽然专门针对BAT或白色脂肪组织（WAT）的中枢神经回路已得到充分证实，但对于这两种脂肪类型共有的神经输入的本质，人们的认识仍在不断发展。此外，对于WAT的棕色化成分——米色脂肪的特定中枢和外周神经支配情况，目前尚无清晰的认识。本研究的目的是在同一动物中研究BAT和WAT的神经输入，并通过将不同组别的大鼠暴露于热中性或寒冷条件下，确定中枢神经组织的变化，以确保在腹股沟白色脂肪组织（iWAT）棕色化后，米色脂肪能够被适当募集和调节。在热中性条件下，将嗜神经性（伪狂犬病）病毒注射到BAT和WAT中，结果表明存在专门的轴突投射，以及投射到这两种脂肪类型的指令神经元的轴突侧支。冷暴露后，针对iWAT的中枢神经回路显示出重组的迹象，在下丘脑（室旁核和下丘脑外侧区）和脑干（苍白球中缝核和蓝斑）部位，投射到棕色和米色WAT的指令神经元有更多的表现。这种转变是由寒冷条件下投射到iWAT的脊髓上神经元数量增加所驱动的。这些数据为WAT棕色化后神经连接水平上的神经系统重组提供了证据——维德曼，N.M.，斯特凡尼迪斯，A.，奥尔德菲尔德，B.J.棕色、白色和米色脂肪组织的中枢神经投射特征。
