Cortisol Secretion Is Related to Electroencephalographic Alertness in Human Subjects during Daytime Wakefulness1

Florian Chapotot, Claude Gronfier, Christophe Jouny, Alain Muzet, Gabrielle Brandenberger
1998 Journal of Clinical Endocrinology and Metabolism  
To determine whether human hypothalamo-pituitary-adrenal axis activity is related to the alertness level during wakefulness, 10 healthy young men were studied under resting conditions in the daytime (0900 -1800 h) after an 8-h nighttime sleep (2300 -0700 h). A serial 70-sec gaze fixation task was required every 10 min throughout the daytime experimental session. The corresponding waking electroencephalographic (EEG) segments were submitted to quantitative spectral analysis, from which EEG ␤
more » ... rom which EEG ␤ activity (absolute power density in the 13-35 Hz frequency band), an index of central alertness, was computed. Blood was collected continuously through an indwelling venous catheter and sampled at 10-min intervals. Plasma cortisol concentrations were measured by RIA, and the corresponding secretory rates were determined by a deconvolution procedure. Analysis of individual profiles demonstrated a declining tendency for EEG ␤ activity and cortisol secretory rate, with an overall temporal relationship indicated by positive and significant cross-correlation coefficients between the two variables in all subjects (average r ϭ 0.565, P Ͻ 0.001). Changes in cortisol secretion lagged behind
doi:10.1210/jcem.83.12.5326 pmid:9851761 fatcat:ban7m6tysnhhzc5wwsubzytlju