CALBINDIN AND PARVALBUMIN IMMUNOREACTIVITY IN THE DEVELOPING AND ADULT HUMAN RETINA

We report the expression and pattern of two calcium-binding proteins ( CBPs), calbindin (CALB) and parvalbumin (PV), in the fetal (13-25 week s of gestation), postnatal (5 months) and adult human retina, as studi ed by immunohistochemistry. Both CBPs appear prenatally in different n eurones as well as in the nerve fibre, inner and outer plexiform layer s. The cones do not show immunoreactivity for both CBPs up to 25 weeks , the last fetal stage studied; however, they are immunopositive in th e postnatal and adult retina. Of the two CBPs, CALB appears first, fol lowed by PV. The immunoreactivity for both CALB and PV in the fetal re tina follows a centroperipheral gradient and vitreal to scleral patter n of retinal differentiation. The CALB immunoreactivity shows a gradua l increase in intensity with age. A spurt in intensity of PV immunorea ctivity in the 24-25 week fetal retina and increased intensity in the 60 year normal adult retina when compared to the light-deprived retina of a 34-year-old staphyloma patient suggests an activity-dependent fu nctional role for PV.