Journal of pineal research
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Early investigations of the effect of sleep deprivation on plasma melatonin reported no major changes. Recently, 36 hrs of sleep deprivation was reported to elevate melatonin levels on the post-sleep deprivation night. Given these contradictions melatonin, cortisol, prolactin, and thyroid stimulating hormone before, during, and, after sleep deprivation were examined in nine healthy young males following one night of sleep deprivation. ⋯ TSH levels showed a similar rise during the control and sleep deprivation nights, but remained flat on the post-sleep deprivation night. It appears that the pineal is insulated against feedback from changes to the level of arousal accompanying sleep and wakefulness. In comparison, cortisol, prolactin, and TSH levels vary with these states and are, therefore, useful indices of arousal and sleep-wake.