The development of ocular dominance columns in normal and visually deprived monkeys.

The main purpose of this study was to examine the normal postnatal development of ocular dominance columns in the striate cortex of the macaque monkey and to determine how this developmental process is influenced by monocular lid-suture. The physiological pattern of ocular dominance was studied in long, tangential electrode penetrations. For anatomical demonstration of the distribution of afferents we relied principally on the transneuronal transport of [3H]proline injected into one eye, and to a lesser extent on the Liesegang silver method. The effects of deprivation on cell size in the lateral geniculate nucleus (LGN) were also studied. Twenty-six monkeys, divided into 5 groups (A-E), were used. A) The process of normal columnar development was examined in four monkeys aged from 1 t o 6 weeks. At one week, there was both an anatomical and a physiological mixing of leftand right-eye inputs to layer IVC, but the basic columnar pattern was evident, and some small regions were already monocular. At three weeks the columnar pattern resembled that seen in the adult, except for a suggestion that the borders between columns were not so sharply demarcated. By six weeks an adult degree of columnar segregation was