Relationship between tryptophan and serotonin concentrations in postmortem human brain.

Abstract

The present study was planned to test a recent observation of positive correlation between tryptophan and 5-hydroxyindole concentrations in postmortem human hypothalamic samples. Four other brain areas were studied, but no significant correlations were observed between tryptophan and serotonin or 5-hydroxyindoleacetic acid concentrations, except in the nucleus accumbens samples of a suicide victim group. A possible in vivo correlation may have been obscured by postmortem changes. The use of tryptophan concentrations as an index for normalising postmortem brain serotonin data is not supported by the present results.