Developmental variations in CSF monoamine metabolites during childhood.

Cerebrospinal (CSF) fluid content of the stable metabolites homovanillic acid, 3-methoxy-4-hydroxyphenyl glycol and 5-hydroxyindoleacetic acid were measured in 19 children without neurological disease known to alter CSF monoamine metabolites. The CSF levels of all three metabolites were found to be up 6 times higher in early infancy compared to the values during adolescence. The levels decreased in a logarithmic fashion, and adult values (approx. 25-50 ng/ml) were reached at 3-5 years of age. Two different interpretations of the findings are discussed: (1) a higher release or turnover of central serotonin and catecholamine metabolites during early postnatal age, or (2) lower clearance of the stable acid metabolites from CSF during infancy due to relatively immature active transport mechanisms.