Functional Plasticity in the Immature Striate Cortex of the Monkey Shown by the [ ¹⁴ C]Deoxyglucose Method

Abstract

Autoradiographic representation of the local rates of cerebral glucose utilization and local cerebral functional activity by means of the [14C]deoxyglucose technique reveals the existence of the ocular dominance columns in the striate cortex of the monkey in the first day of life. In contrast to the stability of these columns in more mature brain, monocular deprivation for 3 months from the first day of life results in their complete disappearance and a reversion of the autoradiographic pattern to that seen in animals with normal binocular vision. These results are consistent with a reorganization of the representation of the visual fields of the two eyes in the striate cortex and provide additional evidence of the plasticity of the striate cortex of the monkey in early life.

Postnatal development of the visual cortex and the influence of environment

“…In the newborn monkey we were able to show by eye injection of 3 H-proline that the inputs from the two eyes are strongly overlapping with only a mild fluctuation in eye dominance in a bandlike pattern. 13 Sokoloff and his colleagues 69 confirmed this observation using the 2-deoxyglucose method. In the monkey foetus Rakic showed that initially the left and right-eye afferents overlap completely, and not until a few days before birth do they begin to sort out into ocular dominance columns.…”

Functional and Anatomic Recovery in the Monkey Brain following Excision of Fetal Encephalocele

“…Recent interest in the practical and theoretical aspects of the transplantation of highly vascular em bryonic or fetal neural tissue into brains [19][20][21][22], and the search for new neuronal growth factors [23] should pro vide a better understanding of CNS response to injury, particularly to development of connectivity in the CNS and its potential for rapid self repair and regrowth in utero. Many recent studies carried out on a cellular and molecular level will provide better understanding of fe tal neural tissue plasticity and regeneration [24][25][26][27], The latter is particularly poorly understood and probably greatly undervalued. There is a strong indication that the ability for rapid growth and regeneration processes, as well as cytoarchitectural reorganization of neural tis sue, is very high in the fetal and neonatal stage [28] ex tended by neuron migration, and probably decreases with postnatal axonal maturation [18].…”

Changes in protein synthesis underlying functional plasticity in immature monkey visual system.

“…The ocular dominance columns are present, but they are less discretely defined, and there is some overlapping of representation of the two eyes in 'adjacent columns (2,3). The system also' exhibits a considerable degree of plasticity.…”

“…The system also' exhibits a considerable degree of plasticity. If, in a young monkey, binocular visual balance is chronically impaired-for example, by unilateral enucleation, insertion ofan opaque lens, orlid suture-then the ocular dominance columns representing the functioning eye extend their boundaries and broaden at the expense ofthe adjacent columns representing the deprived eye; eventually, most of the striate cortex may be incorporated into a monocular visual system that serves onlythe undeprived eye (3,4). The organization of the geniculate body, however, remains normal (2).…”