Vizzard M A, Brisson M, de Groat W C
University of Vermont, College of Medicine, Department of Neurology, Burlington 05405, USA.
Cell Tissue Res. 2000 Jan;299(1):9-26. doi: 10.1007/s004419900128.
Transneuronal tracing with pseudorabies virus (PRV) was used to identify sites in the central nervous system involved in the neural control of colon function. PRV-immunoreactive (IR) cells were primarily localized to the caudal lumbosacral (L6-S1) and caudal thoracicrostral lumbar (T13-L1) spinal segments with the distribution varying according to survival time (72-96 h). In the lumbosacral spinal cord at all time points examined, significantly (P < or = 0.005) greater numbers of PRV-IR cells were present in the region of the sacral parasympathetic nucleus (SPN) of the S1 spinal segment compared to that of the L6 segment. These studies also revealed morphologically distinct cell types with a differential distribution (probably interneurons and preganglionic parasympathetic neurons) in the region of the SPN in the L6-S1 spinal segments following colon inoculation. PRV-labeled neurons were located at various levels of the neuraxis and at many sites had a distribution similar to that following injection of virus to other urogenital organs. However, some unique sites in the dorsal motor nucleus of the vagus, nucleus of the solitary tract, nucleus ambiguus and area postrema were also identified. To determine if labeling in these caudal medullary sites was mediated by spinal or vagal pathways, the colon was inoculated with PRV in animals with a complete spinal cord (T8) transection (5-7 days prior). Following spinal transection, PRV-infected cells were detected in the same caudal medullary regions; however, labeling in other regions (e.g., Barrington's nucleus) was eliminated or significantly reduced. These studies have yielded several novel observations concerning the central neural control of colonic function: (1) the preganglionic efferent and primary afferent innervation of the colon arises primarily from the S1 spinal segment; (2) the distribution of PRV-infected neurons in the central nervous system following colon inoculation was similar to that following PRV inoculation of other urogenital organs; (3) Barrington's nucleus, which has been identified previously as the pontine micturition center, may have a role in colonic function; and (4) PRV infection in Barrington's nucleus following colon inoculation is mediated by bulbospinal pathways whereas labeling in caudal medullary regions is mediated, at least in part, by vagal pathways.
利用伪狂犬病病毒（PRV）进行跨神经元追踪，以确定中枢神经系统中参与结肠功能神经控制的部位。PRV免疫反应性（IR）细胞主要定位于腰骶尾部（L6-S1）和胸腰尾部（T13-L1）脊髓节段，其分布随存活时间（72-96小时）而变化。在所有检查的时间点，与L6节段相比，S1脊髓节段骶副交感核（SPN）区域中存在的PRV-IR细胞数量在腰骶脊髓中显著更多（P≤0.005）。这些研究还揭示了在结肠接种后，L6-S1脊髓节段SPN区域中形态上不同的细胞类型及其不同的分布（可能是中间神经元和节前副交感神经元）。PRV标记的神经元位于神经轴的不同水平，并且在许多部位的分布与向其他泌尿生殖器官注射病毒后的分布相似。然而，还确定了迷走神经背运动核、孤束核、疑核和最后区中的一些独特部位。为了确定这些延髓尾部部位的标记是否由脊髓或迷走神经通路介导，在脊髓完全横断（T8）的动物（5-7天前）中给结肠接种PRV。脊髓横断后，在相同的延髓尾部区域检测到PRV感染的细胞；然而，其他区域（如巴林顿核）的标记被消除或显著减少。这些研究得出了关于结肠功能中枢神经控制的几个新观察结果：（1）结肠的节前传出和初级传入神经支配主要来自S1脊髓节段；（2）结肠接种后中枢神经系统中PRV感染神经元的分布与其他泌尿生殖器官接种PRV后的分布相似；（3）先前已被确定为脑桥排尿中枢的巴林顿核可能在结肠功能中起作用；（4）结肠接种后巴林顿核中的PRV感染由延髓脊髓通路介导，而延髓尾部区域中的标记至少部分由迷走神经通路介导。
