移植的5—羟色胺能神经元跨软脊膜迁入大鼠脊髓的研究

本文对移植的5-HT神经元从蛛网膜下腔跨软脊膜迁移进入脊髓作了初步研究。将含有5-HT细胞的胚胎中缝核组织小块或神经细胞悬浮液作为移植物,以5-HT免疫组织化学方法跟踪移植细胞,结果如下:(1)在低胸水平横切脊髓,10d后,横断脊髓内的5-HT纤维消失。(2)横切脊髓(方法同上)后,立即将中缝核组织小块移植在胸腰段脊髓的蛛网膜下腔,一月后.在横断脊髓内出现5-HT阳性神经元和纤维。5-HT纤维能在灰白质内延伸。(3)脊髓横断后,若以中缝核的细胞悬浮液代替组织小块,作上述移植,则在移植区附近的灰质内出现大量的5-HT阳性神经元。这些神经元在灰质内的分布范围与神经细胞悬浮液在蛛网膜下腔的移植范围相一致。迁入神经元能在灰质内重新形成5-HT阳性纤维网。(4)经上述移植后,灰质内出现的5-HT阳性纤维随远离细胞体而变得稀疏。白质内的5-HT阳性纤维远比灰质内稀少。本实验结果表明:移植在脊髓蛛网膜下腔的脑干5-HT细胞能跨软脊膜迁移进入脊髓。

A STUDY OF TRANSPIAL MIGRATION OF IMPLANTED SEROTONERGIC NEURONS IN RAT SPINAL CORD

Transpial migration of implanted 5--HT neurons from the subarachnoid space intothe spinal cord was studied in adult Wistar rats. Embryonic raphe tissue or cell suspension containing 5--HT cells was used as grafts. The implanted 5--HT cells were monitored by 5--HT immunohistochemical method. The results are as follows:(1)10d after cutting the spinal cord at fower thoracic level, 5--HT fibers disappeared in the tran--sected spinal cord. (2) Raphe tissue was implanted into the subarachnold space of thethoracic lumbar segment after the spinal cord was cut.One month later,5--HT positive cells could be found in the transceted spinal cord with fibers extending into boththe grey and the white matters. (3) If the raphe cell suspension instead was implanted, a number of 5--HT positive cells appeared in the grey matter near the implanted region and the distribution of these cells in the grey matter was quite consistent with theimplanted range of the cell suspension in the subarachnoid space.The 5--HT positivecells which had entered into the spinal cord sent out fibers and reestablished a newfiber network in the grey matter. (4) After implantation, the number of the 5--HTpositive fibers in the transected grey matter became more and more sparsely distributedwith increasing distance from the cell bodies and the 5--HT positive fibers reappearedin the white matter were much less than in the grey matter. Present results show that the implanted 5--HT neurons are able to migrate transpi-ally from the subarachnoid space into the spinal cord.