Callosal projections of the striate cortex in the neonatal rabbit

Callosal fiber projections of the striate cortex were studied in newborn rabbits using the methods of 1) retrograde transport of horseradish peroxidase (HRP) and 2) orthograde transport of tritiated leucine. Data collected from 6-8 day old animals revealed not only the existence of adult-like commissural fibers in the lateral striate cortex bordering the occipital area, but also an aberrant callosal projection from the medial striate cortex, an area not known to have any commissural fibers in the adult brain of those mammalian species studied.