Visual field representation in the newborn rabbit's cortex.

The representation of the visual field in the newborn rabbit's visual cortex appears on about the 10th day after the animal's birth coinciding with the time of its eye opening. Initially the visual response is obtained from a small anterolateral segment of the visual area of the cortex representing a few degrees of the extreme nasal vision of the animal. Even at this early stage, the visually responsive area of the rabbit's cortex seems to organize into V1 and V2 with the binocular response confined to V1 only. By the 15th day after the animal's birth, the visually responsive area in the newborn rabbit extends medially and posteriorly over the cortex, representing more of the animal's temporal and superior visual fields. By this time the binocular response is established over a narrow zone of the animal's visual cortex, representing a few degrees of the nasal visual field, on either side of the boundary between V1 and V2. Between the 16th and 17th day after the rabbit's birth, the cortical representation of the animal's visual field extends medially to the margin of the fissura sagittalis lateralis and caudally to the posterior pole of the hemisphere. In this visually responsive area of the cortex, the band-shaped visual field of the newborn rabbit is asymmetrically represented.