Relationship between natural variations in motoneuron number and body size in Xenopus laevis: a test for size matching.
Relationship between natural variations in motoneuron number and body size in Xenopus laevis: a test for size matching.
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非洲爪蟾运动神经元数量自然变化与体型之间的关系：尺寸匹配测试。
DOI：
10.1002/cne.902640209
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Sperry,DG
中科院分区：
文献类型：
--
作者：
Sperry,DG
在正常的发育过程中，非洲爪蟾蝌蚪在变态过程中表现出巨大的体型变化。这种大小的变化存在于产生腰椎外侧运动柱（L-LMC）运动神经元和该神经元群体中发生神经元细胞死亡的阶段。身体大小、后肢大小、运动神经元数量和运动神经元大小（即，在三个发育阶段的动物中测量神经元核横截面积）：一个在显著量的细胞死亡之前，一个在细胞死亡的峰值速率，一个在细胞死亡之后。神经元群体大小与外周大小相匹配的假设通过使用在这些阶段中的每个阶段发现的自然大小变化来检验。细胞死亡后，运动神经元数目和肌纤维数目与个体大小呈显著正相关。由于这些相关性是随着细胞死亡减少神经元数量而出现的，因此可能发生了大小匹配，并且细胞死亡可能调整了L-LMC运动神经元群体的大小以适应身体大小的变化。除了身体大小和运动神经元数量之间的相关性，在细胞死亡结束时，神经元数量之前和之后的细胞死亡组之间的兄弟姐妹显着相关。讨论了细胞死亡后神经元数量也受到L-LMC祖细胞数量差异影响的可能性。
During normal development, tadpoles ofXenopus laevisdemonstrate large variations in body size that are carried through metamorphosis. This variation in size exists at the stages when lumbar lateral motor column (L‐LMC) motoneurons are produced and when neuronal cell death in this neuron population occurs. Body size, hindlimb size, motoneuron number, and motoneuron size (i.e., neuron nuclear cross‐sectional area) were measured in animals from three developmental stages: one prior to significant amounts of cell death, one at the peak rate of cell death, and one after cell death. The hypothesis that neuron population size is matched to peripheral size was tested by using the natural size variation found at each of these stages.The ranges of values for the measurements at the three stages were large. Significant correlations between body size and motoneuron number, as well as between motoneuron number and muscle fiber number, were present after cell death. Since these correlations emerged as cell death reduced neuron numbers, size matching may have occurred and cell death may have adjusted the L‐LMC motoneuron population's size to variation in body size. In addition to the correlations between body size and motoneuron number at the end of cell death, neuron numbers before and after cell death were significantly correlated among groups of siblings. The possibility that the number of neurons after cell death was also influenced by differences in the number of L‐LMC progenitors is discussed.