An adult-like pattern of ocular dominance columns in striate cortex of newborn monkeys prior to visual experience

Abstract

In macaque monkeys, the geniculocortical afferents serving each eye segregate in layer IVc of striate cortex during early life into a pattern of alternating inputs called ocular dominance columns. It has been disputed whether visual experience is necessary for the formation of ocular dominance columns. To settle this issue, fetal monkeys were delivered prematurely by Caesarean section at embryonic day 157 (E157), 8 d before the end of normal gestation. To avoid light exposure, the Caesarean section and all subsequent feedings and procedures were done in absolute darkness, using infrared night-vision goggles. Tritiated proline was injected into the right eye 1 d after delivery (E158). One week later at postnatal age 0 (P0), the equivalent of a full-term pregnancy (E165/P0), alternate sections of unfolded and flattened visual cortex were prepared for autoradiography or cytochrome oxidase (CO). All three newborns studied at E165/P0 had well segregated ocular dominance columns organized into the characteristic mosaic present in adults. In the upper layers, a mature pattern of CO patches (also known as blobs or puffs) was visible, aligned with the ocular dominance columns in layer IVc. Every other row of patches in layers II, III was labeled by [3H]proline. In V2, a distinct system of alternating thick-pale-thin-pale CO stripes was present. These findings indicate that stimulation of the retina by light is not necessary for the development of columnar systems in the visual cortex. Ocular dominance columns, patches, and V2 stripes all are well formed before visual experience. Even the thalamic input to the patches in the upper layers of striate cortex is segregated by eye in newborns.

Analysis of the postnatal growth of visual cortex

“…When this model is applied to the development of visual cortical columns, it predicts that where the shape of V1 is conserved and merely expands, the optimal patterns will be unchanged. This notion is supported by recent findings that the ocular dominance pattern in newborn macaques is already adult-like (Horton & Hocking, 1996a) and that the orientation map in young ferrets is also similar to those found in the adult (Chapman et al, 1996).…”

“…The brain was removed from the cranium and the cerebral hemispheres were resected and unfolded and flattened following procedures described previously (Olavarria & Van Sluyters, 1985a,b, Murphy et al, 1995 with the modification that paraformaldehyde was used for fixation. Subsequent to flattening, the cortex was placed between glass slides and postfixed with 2% paraformaldehyde and 30% sucrose in PBS (48C) for Horton and Hocking (1996a). b Horton and Hocking (1996b).…”

Modular organization of intrinsic connections associated with spectral tuning in cat auditory cortex

“…The 1.7-mm interval between NB subregions approximates the distance between the centers of matched ocular dominance columns in monkey (6,38) and cat (5, 37) VI. Horizontal projections in VI link columns with common ocular dominance and orientation selectivities (6) and different retinotopic centers for activation (4).…”

The role of nAChR‐mediated spontaneous retinal activity in visual system development

“…ODCs form long before there is sensory input and very soon after LGN neurons arrive at layer 4 of visual cortex (Horton and Hocking, 1996;Crowley and Katz, 2000;Crair et al, 2001). As a means of determining whether retinal activity is required for the early formation of ODCs, Crowley and Katz recently conducted binocular enucleations very early in development (Crowley and Katz, 1999).…”