Distribution of GABA-immunolabeling in the early zebrafish (Danio rerio) brain

The spatial and temporal pattern of GABA-expression in the brains of zebraf ish (Danio rerio) embryos was studied by means of immunohistochemical techn iques. GABA is said to exert neurotrophic actions in the early regulation o f the differentiation of the central nervous system. In early stages GABAer gic cells form distinct clusters throughout the CNS. As development progres ses, more GABAergic clusters appear, and a pattern of GABAergic axonal proj ections is well defined. Although there is a corresponding pattern of distr ibution and appearance of GABA-expression in the brain of different teleost s, further studies are needed to establish its role during early morphogene sis of the CNS of vertebrates.