IMMUNOCYTOCHEMICAL LOCALIZATION OF CHOLINE-ACETYLTRANSFERASE IN RAT CEREBRAL-CORTEX - A STUDY OF CHOLINERGIC NEURONS AND SYNAPSES
IMMUNOCYTOCHEMICAL LOCALIZATION OF CHOLINE-ACETYLTRANSFERASE IN RAT CEREBRAL-CORTEX - A STUDY OF CHOLINERGIC NEURONS AND SYNAPSES
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DOI：
10.1002/cne.902340103
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发表时间：
1985-01-01
影响因子：
2.5
通讯作者：
VAUGHN, JE
中科院分区：
文献类型：
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作者：
HOUSER, CR;CRAWFORD, GD;VAUGHN, JE
胆碱乙酰转移酶（ChAT），乙酰胆碱合成酶和胆碱能神经元的明确标志物，在大鼠大脑皮质的运动和躯体感觉区的单克隆抗体的免疫细胞化学定位。ChAT阳性（ChAT+）静脉曲张的纤维和终端样结构分布在整个皮质松散的网络。一些免疫反应阳性的皮质纤维与皮质下的白色物质中的纤维是连续的，这些纤维中的许多可能起源于皮质下胆碱能神经元。ChAT+纤维似乎是相当均匀地分布在所有层的运动皮层，但一个微妙的层状模式是明显的躯体感觉皮层，其中较低浓度的纤维在层IV与较高浓度的层V. EM表明，免疫反应产物集中在突触囊泡填充的配置文件，许多这些结构形成突触接触。ChAT+突触存在于所有的皮质层，大多数是对称型，虽然也观察到一些不对称的。最常见的突触后成分是来源不明的小到中等大小的树突轴。ChAT+终端形成突触接触顶端，可能，锥体神经元的基底树突，以及与ChAT阴性的非锥体神经元的胞体。ChAT+细胞体存在于整个皮质层II-VI，但最集中在层II-III。胞体的大小和大多数的ChAT+神经元双极的形式，显示垂直取向的树突，往往延伸到几个皮层层。电镜证实了小神经元胞质内存在免疫反应产物，并显示它们在胞体和近端树突上接受对称和不对称突触。显然，ChAT+细胞是非锥体内在神经元，有一个内在的来源，以及外部来源的胆碱能神经支配的大鼠大脑皮层。
Choline acetyltransferase (ChAT), the acetylcholine-synthesizing enzyme and a definitive marker for cholinergic neurons, was localized immunocytochemically in the motor and somatic sensory regions of rat cerebral cortex with monoclonal antibodies. ChAT-positive (ChAT+) varicose fibers and terminal-like structures were distributed in a loose network throughout the cortex. Some immunoreactive cortical fibers were continuous with those in the white matter underlying the cortex, and many of these fibers presumably orginated from subcortical cholinergic neurons. ChAT+ fibers appeared to be rather evenly distributed throughout all layers of the motor cortex, but a subtle laminar pattern was evident in the somatic sensory cortex, where lower concentrations of fibers in layer IV contrasted with higher concentrations in layer V. EM demonstrated that immunoreaction product was concentrated in synaptic vesicle-filled profiles and that many of these structures formed synaptic contacts. ChAT+ synapses were present in all cortical layers and the majority were of the symmetric type, although a few asymmetric ones were also observed. The most common postsynaptic elements were small to medium-sized dendritic shafts of unidentified origin. ChAT+ terminals formed synaptic contacts with apical and, probably, basilar dendrites of pyramidal neurons, as well as with the somata of ChAT-negative nonpyramidal neurons. ChAT+ cell bodies were present throughout cortical layers II-VI, but were most concentrated in layers II-III. The somata were small in size and the majority of ChAT+ neurons were bipolar in form, displaying vertically oriented dendrites that often extended across several cortical layers. EM confirmed the presence of immunoreaction product within the cytoplasm of small neurons and revealed that they received both symmetric and asymmetric synapses on their somata and proximal dendrites. Evidently, ChAT+ cells are nonpyramidal intrinsic neurons and there is an intrinsic source of cholinergic innervation of the rat cerebral cortex, as well as extrinsic sources.