Development of chloride homeostasis in albino and pigmented rat visual cortex neurons

Albinism has a profound effect on visual development and visual function. Pharmacologically significant alterations of the two most important chloride-transporters--KCC2 (outward transporter) and NKCC1 (inward transporter)--functions were found in albino visual cortex neurons, comprising a higher NKCC1 and a lower KCC2 action. In this study, we compare the early postnatal development of the reversal potential of gamma-aminobutyric acidAR-mediated currents in visual cortex neurons of albino and pigmented rats. At birth we found no differences. At the time of eye opening (second week postnatally) the reversal potential of gamma-aminobutyric acidAR-mediated currents is 15 mV more positive and intracellular Cl- concentration is higher in visual cortex neurons of albinos than of pigmented rats.