Schwaber J S, Rogers W T, Satoh K, Fibiger H C
Neurobiology Group, E.I. du Pont de Nemours & Co., Wilmington, Delaware 19898.
J Comp Neurol. 1987 Sep 15;263(3):309-25. doi: 10.1002/cne.902630302.
An understanding of the organization of cholinergic neurons in the central nervous system has been an important objective for many years. By developing and applying a new electronic method for mapping tissue sections, we have generated original graphic and quantitative findings on forebrain cholinergic neurons that provide new insight into their distribution and organization. Satoh, Armstrong, and Fibiger (Brain Res. Bull. 11:693-720, 1983) have proposed that in the basal forebrain cholinergic neurons with long axons form a continuum rather than being arranged as a series of discrete nuclear groups. It has been difficult, however, by conventional methods of data analysis and display, to test this hypothesis. By using a digital microscopy system, the position of every cholinergic neuron was marked with 1-micron resolution in tissue sections taken at 90-microns or 180-microns intervals through the entire distribution of these neurons in the forebrain. The three-dimensional reconstruction of these neurons in context shows them to be distributed as a continuous cell column. The column twists and changes position as it is deformed by adjacent neuronal structures, such that its shape and continuity would not be apparent without reconstruction into a computer graphics model. Complementary analyses of the distribution of cholinergic interneurons in dopamine-rich regions of the forebrain indicated that there are regional differences between striatal and olfactory tubercle neurons. Cellular morphometry analyses show the population of cholinergic neurons in the rat to be surprisingly homogenous in size, but not in shape. Graphic and quantitative analyses indicated that there is a striking relationship between the distributions of projection and interneuronal cell groups. We conclude that the basal forebrain cholinergic neurons form a continuum. The chemoarchitecture of this cell group does not conform to the usual cytoarchitectural divisions. The present results, however, taken together with the findings based on Nissl-stained sections and connectional and biochemical data, suggest that the region of this neurochemically defined continuum should be reexamined for consideration as a single functional entity or nucleus: a cholinergic basal nuclear complex.
多年来，了解中枢神经系统中胆碱能神经元的组织一直是一个重要目标。通过开发和应用一种用于绘制组织切片的新电子方法，我们在前脑胆碱能神经元方面得出了原始的图形和定量结果，为其分布和组织提供了新的见解。佐藤、阿姆斯特朗和菲比格（《脑研究通报》11:693 - 720，1983年）提出，在前脑基底中，具有长轴突的胆碱能神经元形成一个连续体，而不是排列成一系列离散的核团。然而，通过传统的数据分析和显示方法，很难验证这一假设。通过使用数字显微镜系统，在间隔为90微米或180微米的组织切片中，以1微米的分辨率标记了前脑中这些神经元整个分布区域内每个胆碱能神经元的位置。在其所处环境中对这些神经元进行三维重建后发现，它们分布为一个连续的细胞柱。该柱会随着相邻神经元结构的变形而扭曲并改变位置，以至于如果不重建为计算机图形模型，其形状和连续性就不会明显。对前脑富含多巴胺区域中胆碱能中间神经元分布的补充分析表明，纹状体和嗅结节神经元之间存在区域差异。细胞形态计量学分析表明，大鼠体内胆碱能神经元群体在大小上惊人地均匀，但在形状上并非如此。图形和定量分析表明，投射神经元和中间神经元细胞群的分布之间存在显著关系。我们得出结论，前脑基底胆碱能神经元形成一个连续体。这个细胞群的化学结构不符合通常的细胞结构划分。然而，目前的结果与基于尼氏染色切片以及连接和生化数据的研究结果相结合，表明这个由神经化学定义的连续体区域应作为一个单一的功能实体或核重新审视：胆碱能基底核复合体。
