부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.neuroimage.2005.11.024 Byline: Tali Gorfine (a), Yaniv Assaf (a)(c), Yonatan Goshen-Gottstein (b), Yaara Yeshurun (a), Nava Zisapel (a) Abstract: Melatonin, the hormone produced nocturnally by the pineal gland, is an endogenous regulator of the sleep-wake cycle. The effects of melatonin on brain activities and their relation to induction of sleepiness were studied in a randomized, double-blind, placebo controlled functional magnetic resonance imaging (fMRI) study. Melatonin, but not placebo, reduced task-related activity in the rostro-medial aspect of the occipital cortex during a visual-search task and in the auditory cortex during a music task. These effects correlated with subjective measurements of fatigue. In addition, melatonin enhanced the activation in the left parahippocampus in an autobiographic memory task. Results demonstrate that melatonin modulates brain activity in a manner resembling actual sleep although subjects are fully awake. Furthermore, the fatigue inducing effect of melatonin on brain activity is essentially different from that of sleep deprivation thus revealing differences between fatigues related to the circadian sleep regulation as opposed to increased homeostatic sleep need. Our findings highlight the role of melatonin in priming sleep-associated brain activation patterns in anticipation of sleep. Author Affiliation: (a) Department of Neurobiochemistry, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 69978, Israel (b) Department of Psychology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv 69978, Israel (c) Levie-Edersheim-Gitter Institute for Human Brain Mapping, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv 69978, Israel Article History: Received 4 July 2005; Revised 14 November 2005; Accepted 15 November 2005