SLEEP-DEPRIVATION INCREASES BRAIN-SEROTONIN TURNOVER IN THE DJUNGARIAN HAMSTER

Djungarian hamsters well adapted to a short photoperiod were subjected to 4 h of total sleep deprivation (SD) by gentle handling. Tissue con centrations of monoamines and of their metabolites were measured from several brain areas using HPLC with electrochemical detection. The 5-h ydroxyindoleacetic acid/5-hydroxytryptamine (5-HIAA/5-HT) ratio was si gnificantly increased after SD in the hippocampus, hypothalamus and br ain stem, indicating increased serotonin (5-HT) turnover in those area s, while no changes were found in the frontal cortex and olfactory bul b. Dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) concentrations were elevated in the hypothalamus, while the noradrenaline concentrati ons did not change in any of the measured areas. We conclude that a sh ort SD, which has been shown to elevate EEG slow-wave activity during recovery sleep, specifically increases 5-HT turnover in the brain.