RESUMEN
gamma-Aminobutyric acid (GABA), a major inhibitory amino acid, has a central role in cardiorespiratory regulation. Its measurement in the cerebrospinal fluid (CSF) complements the study of neurotransmission systems. Forty-one children were studied (postnatal age < 1 year). For each child, date of birth, date of sampling and current treatments were collated and their postnatal (days) and postconception (weeks) ages were calculated. CSF samples were studied using reverse phase high performance liquid chromatography (HPLC) with o-phthaldialdehyde derivation and spectro-fluorimetric measurement. A clear increase in levels of GABA was observed around 41 weeks postconception, followed by a progressive decrease, with levels stabilizing after 57 weeks postconception. GABA-regulated neuromodulation therefore appears to be mature at 41 weeks postconception and not at birth. The data could be used in further studies investigating amino acid metabolism in relation to brain function in various neurological disorders.