Lack of relation between dopaminergic and gabaergic mechanisms in chick retina.

The effects of apomorphine and bromocriptine on GABA content, GAD and GABA-T activities in the chick retina, both in conditions of a light cycle of 12 h/day and in conditions of light deprivation for 72 h, were studied. In addition, the effects of a treatment with 2 neuroleptics, having a different action on dopamine receptors, i.e. haloperidol and sulpiride, on the same biochemical parameters were examined. The present results show that all the pharmacological manipulations at the dopaminergic transmission by means of agonists and antagonists at dopamine receptors did not affect GABAergic mechanisms in the chick retina and seem to suggest a lack of relations between dopaminergic and GABAergic mechanisms at this level.