Fetal tissue allografts in the damaged adult visual cortex: physiology and connectivity.

During the past three decades, many studies have examined the capacity of embryonic neural grafts (dissociated cells or tissue blocks) to restore lost functions following various damages to the adult mammalian brain. Only very few focused on the visual system even if it is the optimal system to examine the potential of embryonic neural grafts in repairing point-to-point networks. Collectively, these studies show that, within limits, homologous sheets of fetal tissue grafted in the occipital cortex of adult rodents integrate into the host visual circuitry and are physiologically active.