“…Because of its amenability to embryonic microsurgery and electrophysiological and neuropharmacological experiments, the chick embryo is a particularly useful subject for studies concerning embryogenesis. Many of the aforementioned experiments attesting to the fundamental role of GABA in early neurogenesis, especially those that focused on embryonic motility, have also been performed on chick embryos (Renaud et al, 1978;Pittman and Oppenheim, 1979;Reitzel et al, 1979;Toutant et al, 1979;Reitzel and Oppenheim, 1980;McLennan, 1983;Maderdrut et al, 1986;O'Donovan and Landmesser, 1987;O'Donovan, 1987O'Donovan, , 1989O'Donovan et al, 1992;Ho and O'Donovan, 1993). Despite many physiological, pharmacological, and behavioral experiments concerning GABA-mediated events in neural development, the neurochemical localization of GABA in the central nervous system of chick embryos has received little attention.…”