Biological Psychology Commons^™

The Effect Of Increased Sleep On The Circadian Rhythm Of Salivary Cortisol Concentrations, Mariah Jacqueline Scott

Seton Hall University Dissertations and Theses (ETDs)

Cortisol is a salivary marker for the hypothalamic-pituitary-adrenal axis (HPA) component of the stress response. The activity of the HPA demonstrates a circadian rhythm. It is well known that sleep deprivation increases cortisol concentrations. In this study, we looked at the effect of an increase of one-hour sleep for one month on the circadian rhythm of the HPA.

Eight college subjects (n=8) collected saliva during their normal sleep wake cycle every 4 hours for 24 hours. Saliva collections were repeated after a month of increase of sleep by 1-hour. The subjects also completed demographic forms that asked for age, sex, …

The Contribution Of The Pineal Gland On Daily Rhythms And Masking In Diurnal Grass Rats, Arvicanthis Niloticus, Dorela D. Shuboni, Amna A. Agha, Thomas K. H. Groves, Andrew J. Gall

Faculty Publications

Melatonin is a hormone rhythmically secreted at night by the pineal gland in vertebrates. In diurnal mammals, melatonin is present during the inactive phase of the rest/activity cycle, and in primates it directly facilitates sleep and decreases body temperature. However, the role of the pineal gland for the promotion of sleep at night has not yet been studied in non-primate diurnal mammalian species. Here, the authors directly examined the hypothesis that the pineal gland contributes to diurnality in Nile grass rats by decreasing activity and increasing sleep at night, and that this could occur via effects on circadian mechanisms or …