Monitoring of gamma-aminobutyric acid in human cerebrospinal fluid: downward revision of previous control values.

gamma-Aminobutyric acid (GABA) levels were measured by a radioreceptor assay in cerebrospinal fluid (CSF) specimens from two groups of subjects, one without evidence of neurological or psychiatric disease and one with a variety of neurological disorders for which GABA involvement is not known. Mean GABA concentrations in CSF for the two groups were 117 +/- 10 and 127 +/- 7.4 pmol/ml (means +/- SE for 17 and 41 individuals, respectively). These values were about half of most previously reported mean CSF GABA control values, a fact which may be attributed, at least in part, to a reduction of artifactual increase in GABA levels during sampling, storing, and thawing of CSF samples and GABA analysis. Age and sex had no significant influence on CSF GABA concentration.