Morphology and Distribution of the Vasoactive Intestinal Polypeptide (VIP)-Immunoreactive Amacrine Cells in the Mouse Retina / 대한해부학회지

ABSTRACT

Vasoactive intestinal polypeptide (VIP) is a neuroactive substance that is widely expressed in both non-mammalian and mammalian retinas. In this study, we immunocytochemically identified and investigated the VIP-containing neurons in the mouse retina, which has become an important model for the study of the structure and function of the mammalian retina, mainly because of the wide availability of transgenic animals. VIP immunoreactivity was observed in the somata of the amacrine cells in the inner nuclear layer (INL) and their varicose processes ramifying in strata 1 and 3 of the inner plexifrom layer (IPL). The distribution of VIP-immunoreactive (IR) amacrine cells showed a peak of 430 cells/mm2 in the central retina and minimum values of 50 cells/mm2 in the peripheral one. Double-label experiments demonstrated that all VIP-IR amacrine cells possessed GABA immunoreactivity. These results demonstrate that VIP-IR amacrine cells of the mouse retina make up a neurochemically and morphologically distinct subpopulation of the GABAergic amacrine cell population.