Do columns shrink after monocular enucleation in adults?
In young macaques, monocular enucleation during the critical period of cortical plasticity causes shrinkage of the eye’s ocular dominance columns (Hubel et al., 1977). By contrast, no shrinkage of ocular dominance columns is thought to occur after monocular enucleation in adults. This conclusion is based on a single adult macaque studied by LeVay et al. (1980). Four months after monocular enucleation, this animal received an injection of [3H]proline into the remaining eye. The ratio of column areas serving the normal and missing eye was 1.0:1 in each hemisphere. However, using CO histochemistry, subsequent investigators have obtained conflicting results. Hess and Edwards (1987) reported a dark/light ratio in column widths of 60:40 in opercular cortex 8.5 months after monocular enucleation in adult Cebus apella. In the same species, 4-7 months after monocular enucleation, Rosa et al. (1992) found a “close to 50%” ratio of dark and light stripes in opercular cortex. In the macaque, Tru
