AGE RELATED CHANGES OF BENZODIAZEPINE AND GAMMA AMINO BUTYRIC-ACID BINDING SITES IN THE RAT RETINA

The changes in the number and sensitivity of benzodiazepine and GABA binding sites in the rat retina during postnatal development, adulthood and aging and their functional relationship at different ages were studied. Data indicate an increase in the total number of both GABA and benzodiazepine binding sites with age. The activation of retinal benzodiazepine receptor binding by GABA is significantly reduced in aged rats with respect to young adult and newborn rats. The activation of retinal benzodiazepine receptor binding induced by dark exposure of the animals is present in young adult rats but is lost in aged rats. In the retina of aged rats there is an increase of GABA and benzodiazepine receptors which have lost their functional connection.