Armstrong D M, Pickel V M, Joh T H, Reis D J
J Comp Neurol. 1982 Apr 10;206(3):259-72. doi: 10.1002/cne.902060306.
The ultrastructural morphology and specialized neuronal, vascular, and ventricular associations of tyrosine hydroxylase-labeled neurons are examined within the area postrema of rat brain. Specific antiserum to the purified enzyme is localized throughout the rostrocaudal and dorsoventral extent of the area postrema by means of the peroxidase-antiperoxidase technique. In all regions, peroxidase immunoreactivity for tyrosine hydroxylase is distributed throughout the cytoplasm of selectively labeled neuronal perikarya and processes. The perikarya contain a large nucleus, infolded nuclear membrane, numerous cytoplasmic organelles, and form axosomatic synapses with unlabeled terminals. The majority of the labeled processes are dendrites, which contain ribosomes, microtubules, mitochondria, and scattered vesicles. These dendrites are postsynaptic to unlabeled axon terminals and show membrane specializations with other labeled dendrites and perikarya. In contrast to dendrites, peroxidase-labeled profiles clearly distinguished as axons or axon terminals are sparse and never show membrane specializations with other neuronal or nonneuronal structures within the area postrema. Numerous large processes which could be either axons or dendrites are associated with blood vessels and the ventricular surface of the area postrema. With respect to blood vessels, processes are located either in direct apposition to the external glial membrane, or less frequently, within the perivascular space. The ventricular processes are either associated with blood vessels in the subpial space or distributed among the cilia and villi at the anterior margins of the area postrema. The neuronal and nonneuronal associations of the tyrosine hydroxylase-labeled processes are consistent with a receptor or chemosensor function for catecholamines in this circumventricular organ.
在大鼠脑最后区，对酪氨酸羟化酶标记神经元的超微结构形态以及特殊的神经元、血管和脑室联系进行了研究。通过过氧化物酶-抗过氧化物酶技术，将针对纯化酶的特异性抗血清定位在最后区整个前后和背腹范围内。在所有区域，酪氨酸羟化酶的过氧化物酶免疫反应性分布在选择性标记的神经元胞体和突起的整个细胞质中。胞体含有一个大细胞核、内褶的核膜、众多的细胞质细胞器，并与未标记的终末形成轴体突触。大多数标记的突起是树突，其中含有核糖体、微管、线粒体和散在的囊泡。这些树突是未标记轴突终末的突触后成分，并与其他标记的树突和胞体表现出膜特化。与树突不同，过氧化物酶标记的明显区分为轴突或轴突终末的轮廓很少，且在最后区内从不与其他神经元或非神经元结构表现出膜特化。许多可能是轴突或树突的大突起与最后区的血管和脑室表面相关。关于血管，突起要么直接与外胶质膜相邻，要么较少见地位于血管周围间隙内。脑室突起要么与软膜下间隙的血管相关，要么分布在最后区前缘的纤毛和绒毛之间。酪氨酸羟化酶标记突起的神经元和非神经元联系与该室周器官中儿茶酚胺的受体或化学传感器功能一致。
