Griffioen H A, Duindam H, Van der Woude T P, Rietveld W J, Boer G J
Netherlands Institute for Brain Research, Amsterdam.
Brain Res Bull. 1993;31(1-2):145-60. doi: 10.1016/0361-9230(93)90021-3.
Recovery of circadian drinking rhythms in suprachiasmatic nucleus (SCN)-lesioned rats after fetal SCN grafting was related to the immunocytochemical appearance and fiber outgrowth of vasopressin (VP)-, vasoactive intestinal polypeptide (VIP)-, and somatostatin (SOM)-containing neurons in the implants. At 4 weeks postgrafting, the first recovered animal was found. After longer survival times, 38% of the animals showed recovery. Immunocytochemical evaluation indicated that full maturation of the SCN grafts was not reached until 4 weeks postgrafting. Grafted VP and VIP cells were always located together, whereas SOM cells were clustered nearby but separate. Neuropeptide Y fibers were observed with an increasing fiber density between 2 and 5 weeks posttransplantation and were clustered particularly at the level of the SOM cells. In all rhythm-recovered animals transplants of VP and VIP fibers had grown laterally into the hypothalamus. A few nonrecovered animals also showed ingrowth of such fibers, though more caudally to the lesioned SCN. Many of the nonrecovered rats showed similar stainings but without these efferent outgrowth to the host. We conclude that neither a humoral factor nor the presence of VP and VIP efferents in the host brain alone are enough for the restoration of circadian drinking rhythms.
胎儿视交叉上核（SCN）移植后，SCN损伤大鼠昼夜饮水节律的恢复与植入物中含血管加压素（VP）、血管活性肠肽（VIP）和生长抑素（SOM）的神经元的免疫细胞化学表现及纤维长出有关。移植后4周，发现了第一只恢复的动物。存活时间更长后，38%的动物出现了恢复。免疫细胞化学评估表明，直到移植后4周，SCN移植物才完全成熟。移植的VP和VIP细胞总是位于一起，而SOM细胞聚集在附近但相互分开。在移植后2至5周观察到神经肽Y纤维，其纤维密度不断增加，尤其聚集在SOM细胞水平。在所有节律恢复的动物中，VP和VIP纤维的移植物已横向生长到下丘脑。一些未恢复的动物也显示出此类纤维的长入，尽管其位置更靠尾侧，靠近受损的SCN。许多未恢复的大鼠显示出类似的染色，但没有这些向宿主的传出纤维长出。我们得出结论，单独的体液因子或宿主脑中VP和VIP传出纤维的存在都不足以恢复昼夜饮水节律。
