EXTENT AND TIME-COURSE OF RESTORATION OF DESCENDING BRAIN-STEM PROJECTIONS IN SPINAL-CORD TRANSECTED LAMPREY
EXTENT AND TIME-COURSE OF RESTORATION OF DESCENDING BRAIN-STEM PROJECTIONS IN SPINAL-CORD TRANSECTED LAMPREY
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DOI：
10.1002/cne.903440106
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发表时间：
1994-06-01
影响因子：
2.5
通讯作者：
MCCLELLAN, AD
中科院分区：
文献类型：
--
作者：
DAVIS, GR;MCCLELLAN, AD
本研究的目的是确定的数量下降脑干的预测不同水平的脊髓在正常的幼体海七鳃鳗（Petromyzon marinus），并检查恢复这些预测的动物3-32周后横断的头侧脊髓（类似于10%的身体长度）。在正常动物中，大约1，250，900和825个脑干神经元分别投射到体长的20%，40%和60%。脊髓投射来源于间脑、中脑、三个菱脑网状核、Muller神经元和Mauthner神经元以及尾侧菱脑的四个细胞群。在脊髓横断动物的脑干神经元投射到20%的身体长度的数量随着恢复时间的增加，并在32周后横断的脑干神经元的总数和分布与正常动物没有显着差异。脑干投射在横断后8周首次出现在体长的40%处，并且在横断后32周出现在体长的60%处。脑干投射基本恢复到体长的40%，但恢复有限，仅恢复到体长的60%。近似50个脑干神经元，包括一些Muller细胞，在横断后32周投射到体长的60%，表明在这种脊椎动物的中枢神经系统内可以发生超过50 mm的下行投射的恢复。这些解剖结果进行了讨论，在脊髓横断七鳃鳗运动功能恢复的时间过程。(C)1994 Wiley-Liss，Inc.
The purpose of the present study was to determine the numbers of descending brainstem projections to different levels of the spinal cord in normal larval sea lamprey (Petromyzon marinus) and to examine the restoration of these projections in animals 3-32 weeks after transection of the rostral spinal cord (similar to 10% of body length). In normal animals approximately 1,250, 900, and 825 brainstem neurons projected to 20%, 40%, and 60% of body length, respectively. Spinal projections originated from the diencephalon, mesencephalon, three rhombencephalic reticular nuclei, Muller and Mauthner neurons, and four cell groups in the caudal rhombencephalon. In spinal cord-transected animals the number of brainstem neurons projecting to 20% of body length increased with recovery time, and at 32 weeks post-transection the total number and distribution of brainstem neurons was not significantly different from normal animals. Brainstem projections first appeared at 40% of body length by 8 weeks post-transection, and were present at 60% of body length by 32 weeks post-transection. There was substantial restoration of brainstem projections to 40% of body length but limited restoration to 60% of body length. The similar to 50 brainstem neurons, including some Muller cells, that projected to 60% of body length at 32 weeks post-transection indicate that restoration of descending projections in excess of 50 mm can occur within the central nervous system of this vertebrate. These anatomical results are discussed in relation to the time course of recovery of locomotor function in spinal cord-transected lampreys. (C) 1994 Wiley-Liss, Inc.