Fetal brain tissue transplants reduce visual deficits in adult rats with bilateral lesions of the occipital cortex.

Fetal brain tissue from the occipital or the frontal cortex was implanted into the damaged occipital cortex of adult rats. The animals receiving grafts of embryonic frontal cortex showed partial restoration of brightness discrimination while recipients given homologous implants of occipital cortex were as impaired as those animals with lesions alone. Neither frontal nor occipital grafts aided in the performance of a pattern discrimination problem; both groups of brain-damaged animals were unable to learn the task. Nonetheless, both groups of animals had viable and enlarged grafts with similar neuronal and glial profiles.