LAUSR

One of the pivotal events in neurogenesis is compartmentalization where neural tissue is divided into domains and undergoes functional differentiation. A prominent example is cerebellar development which tructural and functional compartmentalization. Although the general anatomical organization of the cerebellar neural circuit is well defined, its functional organization and development are still unresolved. To address this issue, focusing especially on the compartmentalization, we have applied several optical approaches including optogenetics in zebrafish, which has similar cerebellar circuitries to mammalian ones. In the present study to observe structural compartmentalization, we first performed confocal time-lapse imaging of the neural tube to track cell populations via 4D analysi. We used gbx2:EGPF midbrain hindbrain boundary (MHB). 4D-imaging of five to 24 hours revealed novel types of cell migration, among which is periodic migration from MHB toward the hindbrain including cerebellum, followed by neuronal differentiation. The cell populations with these distinct behaviors might contribute to the heterogeneity of the hindbrain and cerebellar neuronal circuitries. Next, to examine functional the cerebellum, we conducted in vivo calcium imaging of neural activities cerebellar Purkinje cells. With optokinetic response test, Purkinje cells acti Furthermore, optogenetic stimulation the repressed.We will also discuss the recent progress in neural activity voltage sensor ASAP1, whose response was confirmed by tetrodotoxin treatment.