Abstract:
Tanycytes are specialized ependymal cells lining the ventricular spaces of the adult brain and thereby provide an interface between the cerebrospinal fluid (CSF) and brain parenchyma. They act as energy homeostasis, neuroendocrine regulation, and CSF-brain barrier; however, their functional significance in CSF-brain communication currently remains unknown. In the present study, we investigated the presence of tanycytic transcytosis using fluorescent tracers; a GM1 ligand, cholera toxin B (CTB), and a mannose-6-phosphate/insulin-like growth factor-Ⅱ receptor ligand, wheat germ agglutinin (WGA). Both CTB and WGA were incorporated by tanycytes and then released into brain parenchyma in the circumventricular organs such as the organum vasculosum laminae terminalis, subfornical organ, and median eminence, arcuate nucleus, and medullary central canal. Incorporated fluorescent CTB and WGA were released from tanycytes to distribute at neuronal somata. These results indicate that tanycytes of all examined brain regions possess the transport capability of macromolecules from CSF to brain neurons.
摘要:
Tanycytes是成年脑的心室间隙的特化室管膜细胞,从而在脑脊液(CSF)和脑实质之间提供界面。它们充当能量稳态,神经内分泌调节,和脑脊液脑屏障;然而,其在CSF-脑交流中的功能意义目前尚不清楚.在本研究中,我们使用荧光示踪剂研究了单核细胞胞吞的存在;GM1配体,霍乱毒素B(CTB),和甘露糖-6-磷酸/胰岛素样生长因子-Ⅱ受体配体,小麦胚芽凝集素(WGA)。CTB和WGA均由tanycytes掺入,然后释放到室外器官的脑实质中,例如终末血管层。穹窿下器官,和中位隆起,弓状核,和髓质中央运河。掺入的荧光CTB和WGA从腺体细胞释放以分布在神经元躯体处。这些结果表明,所有检查的大脑区域的tanycytes都具有大分子从CSF到脑神经元的转运能力。