Postnatal development of the area centralis of the kitten retina: an electron microscopic study.

The postnatal development of the area centralis of the kitten retina was followed with the electron microscope. After birth, small but well developed photoreceptor outer segments were observed. Cone pedicles formed triads and bipolar cells formed dyads; so, potentially, cone pathways to the ganglion cell were present at this time. By the start of the second week, rod spherules formed shallow invaginations containing both central and lateral processes and rod bipolar cells formed dyads. Thus, potentially, rod pathways to the ganglion cell were present. By the end of the third week, the area centralis was sufficiently well developed to take advantage of the clearing of the optical media which occurs in postnatal development. Maturity was attained during the fifth week.