The birthdates of GABA-immunoreactive amacrine cells in the rat retina

The birthdates of GABAergic amacrine cells in the rat retina were investiga ted by immunocytochemistry using anti-GABA and anti-bromodeoxyuridine (BrdU ) antisera. The ratio of co-localization of GABA to BrdU increased graduall y from embryonic-day 13 (E13) and showed a peak value on E18 in the central retina and on E20 in the periphery. After birth, until postnatal-day 3 (P3 ), a few co-localized cells were observed in the inner nuclear layer (INL). However, in the peripheral retina, co-localized cells were observed in the INL and ganglion cell layer until P5. Our results suggest that the birthda tes of GABA-immunoreactive cells vary, depending on cell-type and that ther e is a temporal lag in the GABA-immunoreactive cell production in the perip heral retina relative to the central retina.