Early visual deafferentation of the cortex results in an asymmetry of somatostatin labelled cells.

Biologically active peptides are distributed widely throughout the nervous system. The distribution of each is not random, but follows a relatively specific pattern. Although the time course of development of a number of peptides has been traced, the factors which determine their distribution and function remain unknown. In this study we report changes which occur preferentially in the distribution of one peptide, somatostatin, in the visual cortex of the rat, as a consequence of early unilateral eye removal. Because the uncrossed retinal projection is so small in the rodent, this manipulation substantially reduces the visual innervation of the cortex ipsilateral to the remaining eye, and is correlated here with an asymmetry in the number of somatostatin positive cells.