Bertrand P P, Kunze W A, Bornstein J C, Furness J B
Department of Physiology, University of Melbourne, Parkville, Victoria, Australia.
Neurogastroenterol Motil. 1998 Dec;10(6):533-41. doi: 10.1046/j.1365-2982.1998.00128.x.
The patterns of innervation of the mucosa by axons of individual primary afferent neurones with cell bodies in the myenteric plexus were studied by mapping sites from which electrical stimulation of the mucosa elicited action potentials (APs) in their cell bodies. Segments of guinea-pig ileum were dissected to reveal the myenteric plexus over half of the intestinal circumference, leaving the mucosa intact over the other half. Intracellular recordings were taken from myenteric neurones located within 1 mm of the intact mucosa. Focal electrical stimuli were applied to the mucosa at multiple locations separated by about 1 mm. Neurones that responded had round or oval cell bodies with several long processes (Dogiel type II) and APs that had an inflection on the falling phase (AH-neurones). Responses consisted of single APs or bursts of APs. Maps of the mucosal projections of 30 neurones were generated. The maximum distances from which individual neurones responded were 7 mm circumferential and 2 mm oral or anal to the cell body with a higher proportion of responses from the oral regions. The areas of intact mucosa calculated to be innervated ranged from 1 mm2 up to approximately 15 mm2 (mean 3.9 mm2; median 2.5 mm2). It is estimated that the areas innervated would be two to three times larger under conditions where part of the mucosa is not removed. Some neurones also responded to a chemical or a mechanical stimulus applied to the mucosa within the electrically mapped area. It is concluded that intrinsic primary afferent neurones have overlapping receptive fields with 230-350 neurones innervating the same region of mucosa.
通过绘制电刺激黏膜在位于肌间神经丛的单个初级传入神经元胞体中引发动作电位（APs）的部位，研究了这些神经元轴突对黏膜的神经支配模式。解剖豚鼠回肠段，以暴露肠周径一半的肌间神经丛，另一半的黏膜保持完整。对位于完整黏膜1毫米范围内的肌间神经元进行细胞内记录。在相距约1毫米的多个位置对黏膜施加局部电刺激。有反应的神经元具有圆形或椭圆形胞体以及几个长突起（多极神经元II型），并且动作电位在下降相有一个拐点（AH神经元）。反应包括单个动作电位或动作电位爆发。生成了30个神经元的黏膜投射图。单个神经元产生反应的最大周向距离为7毫米，相对于胞体的口侧或肛侧距离为2毫米，口侧区域的反应比例更高。计算得出的受神经支配的完整黏膜面积范围为1平方毫米至约15平方毫米（平均3.9平方毫米；中位数2.5平方毫米）。据估计，在未切除部分黏膜的情况下，受神经支配的面积将增大两到三倍。一些神经元也对电映射区域内施加于黏膜的化学或机械刺激有反应。得出的结论是，固有初级传入神经元具有重叠的感受野，230 - 350个神经元支配同一区域的黏膜。
