Comparison of the actions of glycine and related amino acids on isolated third order neurons from the tiger salamander retina

摘要: Abstract Whole cell voltage and current clamp recordings were obtained from third order neurons isolated the salamander retina. Using cross desensitization, structure-function relationship of short chain amino acids on glycine receptor examined. l -Serine, -alanine, β-alanine taurine all desensitized with glycine, but did not show significant desensitization GABA. This indicates that these act at receptor. The potency was ≫ > -alanine -serine. TAG, a reputed selective antagonist, equally effective in blocking currents. There is no evidence for distinct taurine. Amino larger moieties alpha carbon, such as threonine valine, produced inactive ligands. Placing methyl group amine or esterification carboxyl also greatly reduced activity. Based modifications molecule, it appears selectivity results part steric restrictions three sites chain. interference most critical ends, less limiting carbon. Doses -serine had only slight effects experiments, nevertheless large experiments. several endogenous can have membrane voltage, even when their shunting activity may be small. High concentrations agonists records, there little These indicate activate receptor, discrete taurine, β-alanine, Since similar acid terminals, reduction around graded functional significance mediating inhibition.