PT  - JOURNAL ARTICLE
AU  - Vandewalle, Gilles
AU  - Archer, Simon N.
AU  - Wuillaume, Catherine
AU  - Balteau, Evelyne
AU  - Degueldre, Christian
AU  - Luxen, André
AU  - Maquet, Pierre
AU  - Dijk, Derk-Jan
TI  - Functional Magnetic Resonance Imaging-Assessed Brain Responses during an Executive Task Depend on Interaction of Sleep Homeostasis, Circadian Phase, and <em>PER3</em> Genotype
AID  - 10.1523/JNEUROSCI.0229-09.2009
DP  - 2009 Jun 24
TA  - The Journal of Neuroscience
PG  - 7948--7956
VI  - 29
IP  - 25
4099  - http://www.jneurosci.org/content/29/25/7948.short
4100  - http://www.jneurosci.org/content/29/25/7948.full
SO  - J. Neurosci.2009 Jun 24; 29
AB  - Cognition is regulated across the 24 h sleep-wake cycle by circadian rhythmicity and sleep homeostasis through unknown brain mechanisms. We investigated these mechanisms in a functional magnetic resonance imaging study of executive function using a working memory 3-back task during a normal sleep-wake cycle and during sleep loss. The study population was stratified according to homozygosity for a variable-number (4 or 5) tandem-repeat polymorphism in the coding region of the clock gene PERIOD3. This polymorphism confers vulnerability to sleep loss and circadian misalignment through its effects on sleep homeostasis. In the less-vulnerable genotype, no changes were observed in brain responses during the normal-sleep wake cycle. During sleep loss, these individuals recruited supplemental anterior frontal, temporal and subcortical regions, while executive function was maintained. In contrast, in the vulnerable genotype, activation in a posterior prefrontal area was already reduced when comparing the evening to the morning during a normal sleep-wake cycle. Furthermore, in the morning after a night of sleep loss, widespread reductions in activation in prefrontal, temporal, parietal and occipital areas were observed in this genotype. These differences occurred in the absence of genotype-dependent differences in circadian phase. The data show that dynamic changes in brain responses to an executive task evolve across the sleep-wake and circadian cycles in a regionally specific manner that is determined by a polymorphism which affects sleep homeostasis. The findings support a model of individual differences in executive control, in which the allocation of prefrontal resources is constrained by sleep pressure and circadian phase.