Cerebrospinal fluid-contacting neurons in the rat spinal cord, a γ-aminobutyric acidergic system expressing the P2X2 subunit of purinergic receptors, PSA-NCAM, and GAP-43 immunoreactivities:: Light and electron microscopic study
Cerebrospinal fluid-contacting neurons in the rat spinal cord, a γ-aminobutyric acidergic system expressing the P2X2 subunit of purinergic receptors, PSA-NCAM, and GAP-43 immunoreactivities:: Light and electron microscopic study
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DOI：
10.1002/cne.10565
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发表时间：
2003-03-03
影响因子：
2.5
通讯作者：
Schlichter, R
中科院分区：
文献类型：
--
作者：
Stoeckel, ME;Uhl-Bronner, S;Schlichter, R
脑脊液接触神经元（CSFcN）存在于低等脊椎动物的各种脑区域中。在哺乳动物中，它们仅限于脊髓区域，对其投射部位知之甚少。在本工作中，我们研究了一些形态功能的特点，这些神经元在大鼠脊髓的光镜和电镜免疫细胞化学。表达嘌呤能受体P2 X（2）亚单位的CSFcN存在于整个脊髓中，但在胸腰椎和骶骨较低水平更多。这些神经元共表达GAD和多聚唾液酸化神经细胞粘附分子（PSA-NCAM），这是细胞可塑性的标志物。从低胸水平向下，微小的无髓鞘轴突（直径小于200 nm）被紧密地包裹成束，这些轴突沿着室管膜并向腹侧延伸，最终集中在腹侧正中裂的壁上。除了P2 X（2），GAD，γ-氨基丁酸（GABA）和PSA，这些轴突表达GAP-43免疫反应性。此外，他们沿着他们的整个长度与突触结合蛋白和突触素的抗体标记，但这些未能揭示椎管内终末领域。综上所述，我们的观察结果表明，在大鼠脊髓中存在高度可塑性的GABA能CSFcN系统，该系统表达嘌呤能受体的P2 X（2）亚单位。这一原始制度的功能仍有待商榷。在这些神经元中，P2 X（2）受体可能赋予对存在于CSF中或由中央自主区的附近神经元释放的ATP的敏感性。(C)2003 Wiley-Liss，Inc.
Cerebrospinal fluid-contacting neurons (CSFcNs) occur in various brain regions of lower vertebrates. In mammals, they are restricted to medullospinal areas, and little is known about their projection sites. In the present work, we investigated some morphofunctional characteristics of such neurons in the rat spinal cord by light and electron microscopic immunocytochemistry. CSFcNs expressing the P2X(2) subunit of purinergic receptors were present throughout the spinal cord, though more numerous at lower thoracolumbar and sacral levels. These neurons coexpressed GAD and the polysialylated neural cell adhesion molecule (PSA-NCAM), a marker of cellular plasticity. From low thoracic levels downward, tiny amyelinic axons (less than 200 nm in diameter) were tightly packed in bundles, which ran along the ependyma and extended ventrally, eventually concentrating against the walls of the ventral median fissure. In addition to P2X(2), GAD, gamma-aminobutyric acid (GABA), and PSA, these axons expressed GAP-43 immunoreactivity. Moreover, they were labelled along their entire lengths with antibodies against synaptotagmin and synaptophysin, but these failed to reveal intraspinal terminal fields. Taken together, our observations indicate the presence in the rat spinal cord of a highly plastic system of GABAergic CSFcNs that express the P2X(2) subunit of purinergic receptors. The function of this original system remains open to question. In these neurons, the P2X(2) receptors may confer a sensitivity to ATP either present in the CSF or released by nearby neurons of the central autonomic area. (C) 2003 Wiley-Liss, Inc.