Vasoactive intestinal polypeptide (VIP) immunohistochemistry in the rabbit retina

A commercially obtained antiserum to vasoactive intestinal polypeptide (VIP) was used with the avidin-biotin-peroxidase immunohistochemical method to localize VIP-like immunoreactivity in the adult rabbit retina. A population of cell bodies in the inner nuclear layer is specifically stained. The cells are most dense in the central retina (40-50 cells/mm2), and least numerous in the superior periphery (15-20 cells/mm2). The dendritic fields overlap extensively; cells in the periphery have dendritic fields up to 1 mm in diameter. The processes of the cells are in the inner plexiform layer, where they tend to form a tristratified pattern in sublayers 1, 3 and 5. This pattern of lamination is similar to that described by other laboratories for dopaminergic amacrine cells and provides further evidence for an interaction between these two neuromodulators.