Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Brain Res. 2010 Sep 2;1350:18-34. doi: 10.1016/j.brainres.2010.03.059. Epub 2010 Mar 27.
Metabolic homeostasis reflects the complex output of endocrine, autonomic, and behavioral control circuits that extend throughout the central nervous system. Brain regions that control food intake and energy expenditure are privy to continuous visceral sensory feedback signals that presumably modulate appetite, satiety, digestion, and metabolism. Sensory signals from the gastrointestinal tract and associated digestive viscera are delivered to the brain primarily by vagal afferents that terminate centrally within the caudal nucleus of the solitary tract (NST), with signals subsequently relayed to higher brain regions by parallel noradrenergic and peptidergic projection pathways arising within the NST. This article begins with an overview of these ascending pathways identified in adult rats using a standard anterograde tracer microinjected into the caudal visceral sensory region of the NST, and also by immunocytochemical localization of glucagon-like peptide-1. NST projection targets identified by these two approaches are compared to the distribution of neurons that become infected after inoculating the ventral stomach wall with a neurotropic virus that transneuronally infects synaptically-linked chains of neurons in the anterograde (i.e., ascending sensory) direction. Although the focus of this article is the anatomical organization of axonal projections from the caudal visceral NST to the hypothalamus and limbic forebrain, discussion is included regarding the hypothesized role of these projections in modulating behavioral arousal and coordinating endocrine and behavioral (i.e., hypophagic) responses to stress.
代谢稳态反映了内分泌、自主和行为控制回路的复杂输出，这些回路延伸到中枢神经系统。控制食物摄入和能量消耗的脑区接收来自胃肠道和相关消化内脏的连续内脏感觉反馈信号，这些信号可能调节食欲、饱腹感、消化和新陈代谢。胃肠道和相关消化内脏的感觉信号主要通过终止于孤束核尾端（NST）的迷走传入纤维传递到大脑，随后通过 NST 内平行的去甲肾上腺素能和肽能投射途径将信号传递到更高的脑区。本文首先概述了这些在成年大鼠中使用标准顺行示踪剂注射到 NST 的尾内脏感觉区识别出的上行通路，同时还通过胰高血糖素样肽-1 的免疫细胞化学定位进行了概述。这两种方法识别的 NST 投射靶标与感染腹侧胃壁后感染顺行（即上行感觉）方向上突触连接神经元链的神经嗜性病毒的神经元分布进行了比较。虽然本文的重点是来自尾内脏 NST 到下丘脑和边缘前脑的轴突投射的解剖组织，但也包括了这些投射在调节行为觉醒和协调内分泌和行为（即摄食减少）对压力的反应中的假设作用的讨论。
