摘要
本文应用电镜免疫细胞化学方法,研究了大鼠下丘脑室旁核胆囊收缩素(CCK)神经元的超微结构分布和突触联系。结果表明:CCK样免疫反应产物定位于大颗粒囊泡、胞浆基质、小透亮囊泡周围、粗面内质网及线粒体膜上。CCK阳性神经元为大细胞或小细胞,主要分布于室旁核的内侧部、室管膜下区和毛细血管周围。某些阳性胞体作为突触后成分与CCK阴性的轴突末梢形成轴体突触。CCK阳性树突和轴突分布于整个室旁核内。某些阳性树突和轴突作为突触后成分,与CCK阴性结构形成轴树和轴轴突触。某些CCK阳性轴突末梢围绕毛细血管。另一些CCK轴突末梢作为突触前成分分别与CCK阴性细胞形成轴体、轴树和轴轴突触。此外,作者首次发现CCK阳性树突穿过室管膜直接与第三脑室的脑脊液接触,CCK阳性轴突末梢走行于靠近室管膜的第三脑室腔内。上述结果提示:1.室旁按内CCK神经元的胞体、树突和轴突与非CCK神经元可能形成局部神经回路;2.室旁核内CCK神经元与血管之间可能存在神经-血管回路;3.室旁核内接触脑脊液的神经元,可参与形成脑-脑脊液神经体液回路,并通过脑脊液影响和调节远位靶区的机能活动。
Using electron immunocytochemical method, the ultrastructural distribution and the synaptic connections of CCK-containing neurons in the paraventricular nucleus (PVN) of the rat were studied. The results showed that the CCK-like immunoreactive products located in farge granular vesicles, cytoplasmic matrix, at the periphery of small clear vesicles, rough endoplasmic reticulum and the membrane of mitochondria. The CCK-positive nerve cell bodies were large or small in size and distributed mainly in the medial part of the PVN, subependymal region and the vicinity of capillaries. Some of them as postsynaptic elements formed axosomatic synapses with CCK-negative axonal terminals. The CCK-positive dendrites and axons situated everywhere in the PVN. Some of them as postsynaptic elements formed axodendritic and axoaxonic synapses with CCK-negative structures. Some CCK-positive axonal endings surrounded the capillaries. Other CCK axonal terminals as presynaptic elements formed axosomatic, axondendritic and axo-axonic synapses with CCK-negative structures, respectively. In addition, we have first found that the CCK-positive dendrites penetrated ependyma and contacted directly with the cerebrospinal fluid in third ventricle, the CCK-positive axons traveled in the cavity of third ventricle near the ependyma. The above mentioned results suggested: (1) the soma, dendrite and axon of the CCK-containing neurons and CCK-negetive neurons in the PVN might form local neuronal circuit; (2) the neuron vessel circuit might be established between CCK-containing neurons and the blood vessels in the PVN; (3) the CSFcontacting neurons in the PVN may participate in forming brain-cerebrospinal fluid neurohumoral circuit and regulate functional activity of distal target area through the CSF pathway.
出处
《解剖学报》
CAS
CSCD
北大核心
1990年第3期248-252,共5页
Acta Anatomica Sinica
基金
卫生部科学基金
关键词
室旁核
胆囊收缩素
免疫细胞化学
Hypothalamic paraventricular nucleus
Cholecystokinin
Cerebrospinal fluid-contacting neurons
Electron immunocytochemistry
Synapse
