RESUMO
BACKGROUND: Assessment of cerebrospinal (CSF) monoamine metabolites 5-hydroxyindoeacetic acid (5-HIAA) and homovanillic acid (HVA), and the serotonin precursor tryptophan (TRP), in chimpanzees may help in understanding the neurobiology underlying aggressive, impulsive behavior in humans and non-human primates. METHODS: Two CSF samples were obtained from 11 peripubertal chimpanzees 8 months apart and were assayed for monoamine metabolite and TRP concentrations. RESULTS: Substantial inter-individual stability was observed for 5-HIAA (n = 11; r = 0.83, P < 0.001) and HVA (r = 0.91, P < 0.001). Females had significantly higher concentrations of 5-HIAA compared to males (F(1,8) = 7.31; P < 0.05). Levels of 5-HIAA (r = -0.62, P < 0.05), HVA (r = -0.86, P < 0.001) and TRP levels (r = -0.67; P < 0.05) decreased with age. CONCLUSION: Close parallels were observed between chimpanzees and humans with respect to absolute levels, sex effects, ontogeny, and 5-HIAA-HVA correlations, supporting the potential utility of the measures in understanding relationships between monoamine functioning and behavior in chimpanzees and humans.