Stereospecific effects of the alpha-aminoadipic acid on the retina: a morphological and electrophysiological study.
In both frog and chicken an intravitreal injection of the dextrorotatory (D)-isomer of alpha-aminoadipic acid (alpha-aaa) leads to a progressive disappearance of the ERG b-wave without affecting a and c components. Tectal evoked potentials (TEP) are no longer recorded. These physiological effects are concomitant with a specific glial cell damage, without any apparent damage to neurons. The levorotatory (L)-isomer at low concentrations is more gliotoxic than the D-isomer, the ERG b-wave is suppressed, while the amplitude of both a and c components is increased. TEPs are always recorded, i.e., a visual message is still generated in the retina and transmitted to the optic tectum when the Müller cells have been damaged and the b-wave is abolished. At higher concentrations the L-isomer suppresses TEPs and damages both glial and neuronal cells. Thus alpha-aaa appears to be a good tool for analyzing ERG components, especially subcomponents of the c-wave.
D015074:2-Aminoadipic Acid / Q000494:pharmacology*; D000600:Amino Acids, Dicarboxylic / Q000494:pharmacology*; D000818:Animals; D001001:Anura; D002645:Chickens; D004594:Electrophysiology / Q000379:methods; D004596:Electroretinography; D005074:Evoked Potentials, Visual; D008854:Microscopy, Electron; D012160:Retina / Q000166:cytology / Q000187:drug effects* / Q000648:ultrastructure; D013477:Superior Colliculi / Q000502:physiology
D000600:Amino Acids, Dicarboxylic; D015074:2-Aminoadipic Acid