Tanaka S, Sekino Y, Shirao T
Department of Neurobiology and Behavior, Gunma University School of Medicine, 3-39-22, Showa-machi, Maebashi, 371-8511, Gunma, Japan.
Neuroscience. 2000;97(4):727-34. doi: 10.1016/s0306-4522(00)00049-x.
Migration of the granule cells is a major stage of cerebellar maturation. Granule cells express neurotrophins and their receptors; however, their role in cell migration has not been defined. In this study we investigated the effects of exogenous neurotrophins on the movement and neurite extension of granule cells from glial-free cerebellar cell reaggregates in vitro. Our results provide direct evidence that neurotrophin-3 and brain-derived neurotrophic factor differentially affect the granule cells. Neurotrophin-3 significantly affected granule cell movements by decreasing the migration index (the ratio of the number of cells that moved further than half the neurite length) and the speed of cell soma movement, but did not affect neurite length or growth cone migration. In contrast, brain-derived neurotrophic factor and neurotrophin-4 acted on growing neurites and growth cones by significantly increasing neurite length and the speed of growth cone migration, but had no effect either on the migration index or on the speed of the cell soma movement. The results suggest that neurotrophins differentially affect neurite extension and the movements of cerebellar granule cells.
颗粒细胞的迁移是小脑成熟的一个主要阶段。颗粒细胞表达神经营养因子及其受体；然而，它们在细胞迁移中的作用尚未明确。在本研究中，我们在体外研究了外源性神经营养因子对无胶质小脑细胞重聚体中颗粒细胞运动和神经突延伸的影响。我们的结果提供了直接证据，表明神经营养因子-3和脑源性神经营养因子对颗粒细胞有不同的影响。神经营养因子-3通过降低迁移指数（移动超过神经突长度一半的细胞数量的比率）和细胞体移动速度，显著影响颗粒细胞的运动，但不影响神经突长度或生长锥迁移。相比之下，脑源性神经营养因子和神经营养因子-4通过显著增加神经突长度和生长锥迁移速度，作用于生长中的神经突和生长锥，但对迁移指数或细胞体移动速度均无影响。结果表明，神经营养因子对神经突延伸和小脑颗粒细胞的运动有不同的影响。
