Mhw. Greenlee et al., TRANSIENT, HIGH-LEVELS OF SNAP-25 EXPRESSION IN CHOLINERGIC AMACRINE CELLS DURING POSTNATAL OF THE DEVELOPMENT OF THE MAMMALIAN RETINA, Journal of comparative neurology, 394(3), 1998, pp. 374-385
In the present study, we have examined the development of cholinergic
amacrine cells in the retina of the Brazilian opossum, Monodelphis dom
estica. An antibody directed against choline acetyltransferase (ChAT)
revealed that ChAT-like immunoreactivity (ChAT-IR) was first observed
at 15 days postnatal (15PN). By 25PN, ChAT-IR identified two matching
populations of amacrine cells in the inner nuclear and ganglion cell l
ayer. Bromodeoxyuridine birth-dating analysis coupled with immunolabel
ing with the anti-ChAT antibody revealed that the cholinergic amacrine
cells are born postnatally, between 2PN and 15PN. In addition, we hav
e examined the differentiation of the cholinergic amacrine cells by us
ing an antibody directed against a presynaptic terminal-associated pro
tein, synaptosomal-associated protein of 25 kDa (SNAP-25). Double-labe
ling analysis revealed that relatively high levels of SNAP-25-IR were
selectively present in cholinergic amacrine cells prior to eye opening
. However, in the mature retina, high levels of SNAP-BB-IR were no lon
ger observed in the ChAT-IR amacrine cells. These results reveal a dis
tinct period in development, prior to eye opening, when high levels of
SNAP-BB-IR are selectively expressed in cholinergic amacrine cells, T
he specificity and time course of the high levels of SNAP-25 in cholin
ergic amacrine cells may be critical in mediating the transient proper
ties of these calls during visual system development. (C) 1998 Wiley-L
iss, Inc.