Jarvinen M K, Wollmann W J, Powrozek T A, Schultz J A, Powley T L
Department of Psychological Sciences, Purdue University, West Lafayette, IN 47907, USA.
Anat Embryol (Berl). 1999 Feb;199(2):99-112. doi: 10.1007/s004290050213.
Nitrergic (NO) neurons play crucial inhibitory roles in the control of gut motility. Variations in the density of these neurons within the gastrointestinal tract (GI) may provide useful functional information, but, most surveys available have employed limited and/or highly localized samples. It remains unclear to what extent (a) NO neurons are concentrated disproportionately in particular GI regions, or (b) variations in NO cell number merely reflect changes in overall myenteric neuron density. This experiment surveyed the distributions of neuronal nitric oxide synthase-positive (NOS+) and other myenteric neurons in the GI tract, using immunohistochemical and Cuprolinic blue counterstaining techniques. Adjustable sampling grids superimposed on wholemounts were used to investigate the topographic patterns in the stomach (90 sampling sites; 45 per side) and proximal duodenum (63 loci). We present four major findings: First, variations were detected in the number of NOS+ neurons in specific regions of the stomach (e.g., corpus > antrum approximately equal to forestomach) and along both longitudinal (oral > anal) and circumferential (mesenteric > antimesenteric) axes in the duodenum. Second, the variations in NOS+ neuronal counts within each organ covaried with the total number of myenteric neurons at different locations (stomach, r=0.77; duodenum, r=0.59), suggesting that local myenteric plexus density is a factor determining NOS+ cell concentrations. Third, in contrast to such a principle of covariation within each organ, NOS+ neurons constituted a consistently smaller proportion of gastric (20%) than of duodenal (28%) myenteric plexus neurons, suggesting that a second principle controls the characteristic percentages of the myenteric plexus that express NOS in different organs. Fourth, the regional samples were used to extrapolate the overall number of NOS+ and total myenteric cells in the rat stomach (43,000; 217,000) and first 3.5 cm of the small intestine (29,000; 103,000). These results, taken together, also suggest that the surveying protocol used is capable of detecting subtle differences in cellular distributions, thus providing a practical strategy for investigating patterns of chemical phenotypes within the GI tract.
含氮（NO）能神经元在肠道运动控制中发挥着至关重要的抑制作用。胃肠道（GI）内这些神经元密度的变化可能提供有用的功能信息，但大多数现有研究采用的样本有限且/或高度局限。目前尚不清楚：（a）NO能神经元是否不成比例地集中在特定的胃肠道区域；或（b）NO细胞数量的变化仅仅反映了肠肌间神经元总体密度的变化。本实验采用免疫组织化学和硫堇蓝复染技术，研究了胃肠道中神经元型一氧化氮合酶阳性（NOS+）神经元和其他肠肌间神经元的分布。使用叠加在整装标本上的可调采样网格，研究了胃（90个采样点；每侧45个）和十二指肠近端（63个位点）的地形模式。我们得出了四个主要发现：第一，在胃的特定区域（如胃体>胃窦≈前胃）以及十二指肠的纵向（口侧>肛侧）和周向（肠系膜侧>反肠系膜侧）轴上，检测到NOS+神经元数量存在变化。第二，每个器官内NOS+神经元计数的变化与不同位置肠肌间神经元的总数相关（胃，r = 0.77；十二指肠，r = 0.59），这表明局部肠肌间神经丛密度是决定NOS+细胞浓度的一个因素。第三，与每个器官内这种协变原则相反，NOS+神经元在胃肠肌间神经丛神经元中所占比例（20%）始终低于十二指肠（28%），这表明另一个原则控制着不同器官中表达NOS的肠肌间神经丛的特征百分比。第四，利用区域样本推断大鼠胃（43,000个；217,000个）和小肠前3.5厘米（29,000个；103,000个）中NOS+神经元和肠肌间细胞的总数。综合这些结果还表明，所采用的调查方案能够检测细胞分布的细微差异，从而为研究胃肠道内化学表型模式提供了一种实用策略。
