Neurobiology of Nutrition and Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA.
Institute for Anatomy and Cell Biology, Friedrich-Alexander University, Erlangen, Germany.
J Comp Neurol. 2021 May 1;529(7):1465-1485. doi: 10.1002/cne.25031. Epub 2020 Sep 28.
Adipose tissue plays an important role in metabolic homeostasis and its prominent role as endocrine organ is now well recognized. Adipose tissue is controlled via the sympathetic nervous system (SNS). New viral, molecular-genetic tools will soon allow a more detailed study of adipose tissue innervation in metabolic function, yet, the precise anatomical extent of preganglionic and postganglionic inputs to the inguinal white adipose tissue (iWAT) is limited. Furthermore, several viral, molecular-genetic tools will require the use of cre/loxP mouse models, while the available studies on sympathetic iWAT innervation were established in larger species. In this study, we generated a detailed map for the sympathetic innervation of iWAT in male and female mice. We adapted iDISCO tissue clearing to process large, whole-body specimens for an unprecedented view of the natural abdominal SNS. Combined with pseudorabies virus retrograde tracing from the iWAT, we defined the preganglionic and postganglionic sympathetic input to iWAT. We used fluorescence-guided anatomical dissections of sympathetic nerves in reporter mice to further clarify that postganglionic axons connect to iWAT via lateral cutaneous rami (dorsolumbar iWAT portion) and the lumbar plexus (inguinal iWAT portion). Importantly, these rami carry axons that branch to iWAT, as well as axons that travel further to innervate the skin and vasculature, and their functional impact will require consideration in denervation studies. Our study may serve as a comprehensive map for future experiments that employ virally driven neuromodulation techniques to predict anatomy-based viral labeling.
脂肪组织在代谢稳态中起着重要作用，其作为内分泌器官的突出作用现在已得到广泛认可。脂肪组织受交感神经系统（SNS）的控制。新的病毒、分子遗传工具将很快允许更详细地研究脂肪组织神经支配在代谢功能中的作用，但腹股沟白色脂肪组织（iWAT）节前和节后传入的精确解剖范围是有限的。此外，几种病毒、分子遗传工具将需要使用 cre/loxP 小鼠模型，而现有的关于交感 iWAT 神经支配的研究是在较大的物种中建立的。在这项研究中，我们生成了雄性和雌性小鼠 iWAT 交感神经支配的详细图谱。我们对 iDISCO 组织透明化进行了改编，以处理大型全身标本，从而以前所未有的视角观察自然腹部 SNS。结合 iWAT 逆行示踪伪狂犬病毒，我们定义了 iWAT 的节前和节后交感传入。我们使用报告小鼠中荧光引导的交感神经解剖分离，进一步阐明节后轴突通过侧皮支（背腰 iWAT 部分）和腰丛（腹股沟 iWAT 部分）与 iWAT 相连。重要的是，这些分支携带分支到 iWAT 的轴突，以及进一步支配皮肤和血管的轴突，在去神经研究中需要考虑它们的功能影响。我们的研究可以作为未来实验的综合图谱，这些实验采用病毒驱动的神经调节技术来预测基于解剖的病毒标记。
