Somatostatin-like immunoreactivity in the central visual pathway of the prenatal rat.

Somatostatin (SRIF)-like immunoreactivity was localized in the central visual pathway of near-term prenatal rats using light-microscopic immunocytochemistry and a highly specific antibody to the peptide. SRIF was demonstrable in neuronal perikarya and fibers of the lateral geniculate nucleus, superior colliculus and visual cortex. At this stage the distribution of these elements had not attained the pattern seen in the adult. The presence of SRIF in the central visual pathway prior to maturation suggests a role for this peptide in the development of visual function.