Armstrong D M
J Comp Neurol. 1986 Aug 1;250(1):81-92. doi: 10.1002/cne.902500108.
The ultrastructural morphology and vascular associations of cholinergic neurons in the horizontal limb of the nucleus of the diagonal band of Broca (nDBBhl) and amygdala of rat were determined by the immunocytochemical localization of choline acetyltransferase (ChAT), the acetylcholine biosynthetic enzyme. Within the nDBBhl peroxidase reaction product was distributed throughout the cytoplasm of selectively labeled neuronal perikarya and dendrites. Labeled perikarya were characterized by an oval cell body (7-10 microns X 17-26 microns in diameter) in which was located a large nucleus and often a prominent nucleolus. Dendrites were by far the most numerous immuno-labeled profiles in the nDBBhl. The labeled dendrites had a cross-sectional diameter of 0.4-4.6 microns and contained numerous mitochondria and microtubules. Approximately 10% of all immunolabeled dendrites received synaptic contacts from unlabeled presynaptic boutons. In contrast to the relatively large number of ChAT-labeled dendrites within the nDBBhl, ChAT-positive axons were less frequently observed and immunolabeled axon terminals were never detected. The labeled axons had an outside diameter of 0.4-1.4 micron and were myelinated. The absence or relative paucity of immunolabeled terminals in the nDBBhl indicates that most if not all of the cholinergic perikarya within this nucleus are efferent projection neurons. The nDBB is known to have widespread projections to many areas of the neocortex, hippocampus, and amygdala. In the present study we examined the amygdala and observed many ChAT-labeled axon boutons. The immunolabeled varicosities contained numerous agranular vesicles and although ChAT-positive terminals were in direct contact with unlabeled neuronal elements within the amygdala, few if any synaptic densities were detected in a single plane of section. With respect to the vasculature, immunolabeled perikarya and dendrites within the nDBBhl and axon terminals in the amygdala were often in direct apposition to blood vessels. In many instances the labeled profile was observed lying directly on the basal lamina of a capillary endothelial cell. In no instance, however, were membrane densities observed. The presence of cholinergic neuronal elements contacting the vessel wall provides morphologic evidence suggesting that the neurogenic control of cerebral vasculature is in part mediated via a cholinergic mechanism.
通过对胆碱乙酰转移酶（ChAT，乙酰胆碱生物合成酶）进行免疫细胞化学定位，确定了大鼠大脑中布罗卡斜角带核水平支（nDBBhl）和杏仁核中胆碱能神经元的超微结构形态及血管联系。在nDBBhl内，过氧化物酶反应产物分布于选择性标记的神经元胞体和树突的整个细胞质中。标记的胞体特征为椭圆形细胞体（直径7 - 10微米×17 - 26微米），其中有一个大细胞核，且常有一个明显的核仁。树突是nDBBhl中免疫标记最多的结构。标记的树突横截面积为0.4 - 4.6微米，含有大量线粒体和微管。所有免疫标记的树突中约10%接受来自未标记突触前终扣的突触联系。与nDBBhl内相对大量的ChAT标记树突不同，ChAT阳性轴突较少被观察到，且从未检测到免疫标记的轴突终末。标记的轴突外径为0.4 - 1.4微米，有髓鞘。nDBBhl中免疫标记终末的缺失或相对稀少表明该核内大多数（如果不是全部）胆碱能胞体是传出投射神经元。已知nDBB向新皮层、海马体和杏仁核的许多区域有广泛投射。在本研究中，我们检查了杏仁核，观察到许多ChAT标记的轴突终扣。免疫标记的膨体含有大量无颗粒小泡，尽管ChAT阳性终末与杏仁核内未标记的神经元成分直接接触，但在单个切片平面中几乎未检测到突触密度。关于脉管系统，nDBBhl内免疫标记的胞体和树突以及杏仁核中的轴突终末常常与血管直接毗邻。在许多情况下，观察到标记结构直接位于毛细血管内皮细胞的基膜上。然而，在任何情况下都未观察到膜密度。胆碱能神经元成分与血管壁接触的存在提供了形态学证据，表明脑血管的神经源性控制部分是通过胆碱能机制介导的。
