.OMEGA.-Aminosulfonic acids as depressant or excitant compounds: Their effect on the behavior and electroencephalogram of young chickens.

Abstract

Young chickens with inefficient blood-brain barrier were employed to study the effects of aliphatic omega-aminosulfonic acids with varying numbers of carbon chains on the central nervous system. Each of the amino acids was intraperitoneally administered to unrestrained and unanesthetized animals, to investigate its effects upon their behavior and electroencephalogram (EEG). omega-Amino acid with a short-chain structure (3-aminopropanesulfonic acid) had a depressing effect similar to that of gamma-aminobutyric acid which is known as a depressant amino acid. On the other hand, the omega-amino acids with long-chain structure (5-aminopentanesulfonic acid and 6-guanidinohexanesulfonic acid) acted as excitants, induced convulsions and developed typical biphasic spikes with high amplitudes in the EEG. The spikes appeared early, and could be detected at the excitant stage before convulsion. In contrast, with the administration of convulsant drugs, the spikes appeared only after the occurrence of convulsion. However, a high dose (1-9 g/kg) of the omega-amino acids was needed to develop their effects. These results suggest that young chickens are valuable in clarifying the characteristic behavior and the brain electrical activity of omega-amino acids. But the omega-amino acids cannot easily pass through the blood-brain barrier in young chicken.