Tanycytes present in the adult rat mediobasal hypothalamus support the regeneration of monoaminergic axons
Tanycytes present in the adult rat mediobasal hypothalamus support the regeneration of monoaminergic axons
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DOI：
10.1006/exnr.1998.6784
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发表时间：
1998-05-01
影响因子：
5.3
通讯作者：
Alonso, G
中科院分区：
文献类型：
--
作者：
Chauvet, N;Prieto, M;Alonso, G
我们最近发现，存在于正中隆起（RIE）的伸长细胞构成了一个优先支持受损的神经垂体催产素和加压素轴突的再生。然而，尽管延伸细胞在ME中特别丰富，但它们也沿着第三脑室壁存在。因此，本研究进行，以确定是否存在于下丘脑内侧基底部覆盖ME的伸长细胞也能够支持再生的许多monoaminergic轴突支配这一地区。使用激光共聚焦扫描显微镜结合双重或三重荧光免疫染色，我们已经比较了神经胶质细胞和受损的儿茶酚胺能和神经轴突之间发生的关系，在手术切口的水平放置在背内侧下丘脑没有tanycytes或在腹内侧下丘脑含有众多tanycytes过程。在背侧病变中，发现邻苯二酚胺能和多巴胺能横断纤维邻接沿着手术切口形成的瘢痕，并由对胶质细胞酸性蛋白（GFAP）和波形蛋白（Vim）具有强烈免疫反应性的紧密内指状星形胶质细胞突起组成。在腹侧病变中，病变瘢痕由GFAP免疫反应（IR）和VIM-IR星形胶质细胞突起和VIM-IR但GFAP阴性的被鉴定为tanycytic突起组成。在所有的腹侧病变检查，许多儿茶酚胺能和神经纤维被发现再生到手术切口与VIM-IR，GFAP阴性的伸展细胞过程。另一方面，在仅含有GFAP-IR星形胶质细胞结构的瘢痕部分中从未发现这种再生纤维。这些数据表明，像在ME中一样，存在于成年大鼠下丘脑中的延伸细胞提供了有利于受损轴突再生的基质。(C)北京：科学出版社.
We have recently shown that tanycytes present in the median eminence (RIE) constitute a preferential support for the regeneration of lesioned neurohypophysial oxytocinergic and vasopressinergic axons. However, although tanycytes are particularly abundant in the ME, they are also present along the third ventricle wall. This study was thus undertaken to determine whether tanycytes present in the mediobasal hypothalamus overlying the ME were also able to support the regeneration of the numerous monoaminergic axons innervating this region. Using confocal laser scanning microscopy combined with double or triple fluorescence immunostaining, we have compared the relationships occurring between glial cells and lesioned catecholaminergic and serotonergic axons at the levels of surgical cuts placed in the dorsomedial hypothalamus devoid of tanycytes or in the ventromedial hypothalamus containing numerous tanycyte processes. In dorsal lesions, catecholaminergic and serotonergic transected fibers were found to abut onto the scar formed along the surgical cut and composed of closely inderdigitating astrocyte processes strongly immunoreactive for both glial fibrillary acidic protein (GFAP) and vimentin (VIM). In ventral lesions, the lesional scar was composed of GFAP-immunoreactive (IR) and VIM-IR astrocyte processes and of VIM-IR but GFAP-negative processes that were identified as tanycytic processes. In all the ventral lesions examined, numerous catecholaminergic and serotonergic fibers were found to regenerate into the surgical cut in association with the VIM-IR, GFAP-negative tanycyte processes. On the other hand, such regenerating fibers were never found in scar portions containing only GFAP-IR astrocytic structures. These data indicate that, like in the ME, tanycytes present in the mediobasal hypothalamus of adult rat provide a substrate that favors the regeneration of lesioned axons. (C) 1998 Academic Press.