Alterations in retinal neurotransmitter receptors and neuropeptides of the chick by kainic acid and acrylamide.

The effects of intraocular injection of kainic acid and acrylamide upon retinal neuropeptides and high affinity binding sites have been determined in the chick. Kainic acid causes a sharp reduction in Met-enkephalin and somatostatin while neurotensin levels are unchanged. This treatment also lowers the extent of cholinergic muscarinic but not of [3H]naloxone or [3H]spiroperidol binding. In contrast, acrylamide treatment causes major increases of retinal Met-enkephalin and neurotensin concentrations. The binding of [3H]naloxone is also increased, and no reductions of any peptide or binding intensity were observed. The results indicate the plasticity of retinal neuropeptide levels and the selectivity with which these can be modulated.