抄録
During development of cerebral cortex the two major types of neurons, pyramidal and GABAergic neurons, migrate to their destination through different routes and extend their dendrites at different timing. Questions arise whether neuronal activity gives any influence on these processes of neuronal development, and if so, whether its influence differs between the two types of neurons. To address these questions, we used neuron culture preparations of the visual cortex of GAD67-GFP knock-in mice, in which GABAergic neurons can be identified by GFP. With time-lapse imaging analysis we observed effects of drugs, which block or enhance neural activity, on the motility and dendritic development of GABAergic and pyramidal neurons. Until 7 days in vitro (DIV) GABAergic neurons moved very quickly, although the movement was not smooth, while pyramidal neurons did not show such high motility. After their motility diminished, GABAergic neurons started to develop their dendrites. An application of tetrodotoxin (TTX) increased the motility of GABAergic neurons and extended the period when such high motility is maintained. The application of TTX and antagonists for ionotropic glutamate receptors until 7 DIV retarded the dendritic development of GABAergic neurons, while did not significantly affect that of pyramidal neurons. These results suggest that GABAergic neurons are more susceptible to neuronal activity than pyramidal neurons and activity may be a factor to stop migration of GABAergic neurons and to start development of their dendrites. [J Physiol Sci. 2006;56 Suppl:S171]
