Abstract：
There is clear evidence that the sympathetic nervous system (SNS) mediates bone metabolism. Histological studies show abundant SNS innervation of the periosteum and bone marrow-these nerves consist of noradrenergic fibers that immunostain for tyrosine hydroxylase, dopamine beta hydroxylase, or neuropeptide Y. Nonetheless, the brain sites that send efferent SNS outflow to bone have not yet been characterized. Using pseudorabies (PRV) viral transneuronal tracing, we report, for the first time, the identification of central SNS outflow sites that innervate bone. We find that the central SNS outflow to bone originates from 87 brain nuclei, sub-nuclei and regions of six brain divisions, namely the midbrain and pons, hypothalamus, hindbrain medulla, forebrain, cerebral cortex, and thalamus. We also find that certain sites, such as the raphe magnus (RMg) of the medulla and periaqueductal gray (PAG) of the midbrain, display greater degrees of PRV152 infection, suggesting that there is considerable site-specific variation in the levels of central SNS outflow to bone. This comprehensive compendium illustrating the central coding and control of SNS efferent signals to bone should allow for a greater understanding of the neural regulation of bone metabolism, and importantly and of clinical relevance, mechanisms for central bone pain.
摘要：
有明确的证据表明交感神经系统(SNS)介导骨代谢。组织学研究表明，骨膜和骨髓的SNS神经支配丰富-这些神经由去甲肾上腺素能纤维组成，对酪氨酸羟化酶进行免疫染色，多巴胺β羟化酶，或神经肽Y。尽管如此，尚未对向骨骼发送传出SNS流出的大脑部位进行表征。使用伪狂犬病（PRV）病毒跨神经元追踪，我们报告,第一次,确定神经支配骨骼的中央SNS流出部位。我们发现，中枢神经系统向骨骼的流出来自87个脑核，大脑六个分区的亚核和区域，即中脑和脑桥，下丘脑,后脑髓质,前脑,大脑皮层,还有丘脑.我们还发现某些网站，例如延髓的中脉大肌（RMg）和中脑的导水管周围灰色（PAG），显示更严重的PRV152感染，这表明中枢神经系统向骨骼流出的水平存在相当大的位点特异性变化。这个全面的汇编说明了SNS传出信号到骨骼的中央编码和控制，应该允许对骨代谢的神经调节有更多的理解。重要的是和临床相关的，中枢骨痛的机制。
