Determination of glutathione and ATP in ganglia and individual neurons of Aplysia californica.

The levels of two gamma-glutamyl cycle substrates, glutathione and ATP, were determined in single identified nerve cell bodies from the CNS of Aplysia californica. The glutathione content of single cells averaged 30 +/- 4.9 mumol/g protein. Glutathione levels were similar in identified cholinergic, serotonergic, and histaminergic cells, as well as in neurons whose transmitters are not yet identified. The abdominal rostral white cells, which are enriched in glycine, a component amino acid of glutathione, did not possess distinctively higher glutathione concentrations. The ATP content of single Aplysia nerve cell bodies averaged 15.0 +/- 1.5 mumol/g protein. Despite the vast chemical, anatomical, and functional heterogeneity between Aplysia central neurons, no cells were found that contained unusually high or low ATP levels.