Phylogenetical development of somatostatin-containing cells in the retina from teleosts to mammals: immunohistochemical analysis.

The distribution of somatostatin (SRIF) in the retina of various vertebrates (from teleosts to mammals) was investigated by means of indirect immunohistochemical technique. The present study revealed that there exists marked differences in topography of SRIF-containing cell systems between higher vertebrates (birds and rats) and lower vertebrates (amphibian and teleosts). The retinas of the higher vertebrates contain abundant SRIF-positive structures, while those of the lower vertebrates contain a few. Phylogenetical development of retinal SRIF-system was briefly discussed in this study.