Research Project
Grant-in-Aid for Scientific Research (C)
The inhibitory neurons in the mammalian cerebral cortex are born in the basal ganglia in the fetal period. We previously found that the inhibitory neurons in naonatal rat cerebral cortex have higher migratory activity when compared with excitatory neurons. In this research, we investigated when and how these neurons acquire the migratory nature.(1)During the development of brain, neurons at the basal ganglia possessed high migratory activity at embryonic 15 day. We found some cells dividing during the observation and these cells are highly migrative even before the final division, indicating that cells in the basal ganglia are migrative before neuronal differentiation.(2)As microtubules are responsible for the pulling force of cell nucleus during cell migration, we investigated the role of katanin, microtubule severing protein, in the neuronal development. When we introduced siRNA for katanin into cerebral cortical neurons to inhibit katanin expression, axon elongation but not dendrite elongation was impared. This indicate that fragmented microtubules produced by katanin is important for migration of growth cones.(3)Next we investigated the role of ninein, which is a microtubule-minus end binding protein. In the radial cells at the ventricular zone of cerebral cortex, ninein is localized at the centrosome. In differentiated neuron at the cortical plate layer, however, ninein was not localized at the centrosome and was diffusely detected in cytoplasm. This suggest that microtubules are released from centrosome after differentiation of neurons and that the released microtubules are important for the migration and axon elongation of neurons.
All 2007 2006 2005
All Journal Article (12 results)
Cell Motility and Cytoskeleton 64
Pages: 347-359
Cell Motil.Cytoskel 64
Mol Cell Neurosci. 31
Pages: 493-504
Sophia Life Science Bulletin 23
Pages: 39-47
J. Neurochem. 92
Pages: 904-914
J.Neurochem 92
J.Neurochem. 92
40007021860
Journal of Neurochemistry 92
Sophia Life Science Bulletin 22(in press)