title: Sex chromosomes regulate nighttime sleep propensity during recovery from sleep loss in mice.
abstract: Sex differences in spontaneous sleep amount are largely dependent on reproductive hormones; however, in mice some sex differences in sleep amount during the active phase are preserved after gonadectomy and may be driven by non-hormonal factors. In this study, we sought to determine whether or not these sex differences are driven by sex chromosome complement. Mice from the four core genotype (FCG) mouse model, whose sex chromosome complement (XY, XX) is independent of phenotype (male or female), were implanted with electroencephalographic (EEG) and electromyographic (EMG) electrodes for the recording of sleep-wake states and underwent a 24-hr baseline recording followed by six hours of forced wakefulness. During baseline conditions in mice whose gonads remained intact, males had more total sleep and non-rapid eye movement sleep than females during the active phase. Gonadectomized FCG mice exhibited no sex differences in rest-phase sleep amount; however, during the mid-active-phase (nighttime), XX males had more spontaneous non-rapid eye movement (NREM) sleep than XX females. The XY mice did not exhibit sex differences in sleep amount. Following forced wakefulness there was a change in the factors regulating sleep. XY females slept more during their mid-active phase siestas than XX females and had higher NREM slow wave activity, a measure of sleep propensity. These findings suggest that the process that regulates sleep propensity is sex-linked, and that sleep amount and sleep propensity are regulated differently in males and females following sleep loss.
authors: Neuroscience Institute, Morehouse School of Medicine, Atlanta, Georgia, USA.
authors: J Christopher
authors: JC
authors: Ehlen
authors: September
authors: S
authors: Hesse
authors: Lennisha
authors: L
authors: Pinckney
authors: Ketema N
authors: KN
authors: Paul
mesh_terms: D000818:Animals; D003700:Delta Rhythm; D005260:Female; D005838:Genotype; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D012727:Sex Characteristics; D012892:Sleep Deprivation; D012895:Sleep, REM / Q000235:genetics*; D014851:Wakefulness; D014960:X Chromosome / Q000502:physiology*; D014998:Y Chromosome / Q000502:physiology*
references: Sleep. 2001 Sep 15;24(6):680-7
references: 11560181
references: Exp Neurol. 1969 Dec;25(4):616-25
references: 5391423
references: Brain Res. 1996 Sep 23;734(1-2):275-85
references: 8896835
references: Horm Behav. 2008 Jan;53(1):217-24
references: 17976600
references: Brain Res. 1980 Mar 10;185(2):385-98
references: 6101987
references: Physiol Behav. 1971 Jun;6(6):743-6
references: 4337177
references: Front Neuroendocrinol. 2009 Jan;30(1):1-9
references: 19028515
references: Nat Neurosci. 2002 Oct;5(10):933-4
references: 12244322
references: Sleep. 2006 Sep;29(9):1211-23
references: 17040009
references: Neuron. 2008 Dec 26;60(6):943-6
references: 19109901
references: Acta Psychiatr Scand Suppl. 2007;(433):104-15
references: 17280576
references: Sleep Med. 2011 Mar;12(3):215-21
references: 21317033
references: Horm Behav. 2008 Sep;54(4):565-70
references: 18590732
references: J Neurosci. 2010 Jul 7;30(27):9140-4
references: 20610747
references: Am J Physiol. 1995 Jul;269(1 Pt 2):R208-14
references: 7631895
references: Sleep. 2009 Jul;32(7):857-64
references: 19639748
references: J Appl Physiol (1985). 2007 Oct;103(4):1332-8
references: 17641220
references: Sleep. 2010 Jul;33(7):956-61
references: 20614855
references: Hum Mol Genet. 1998 Apr;7(4):715-27
references: 9499427
references: J Sleep Res. 2011 Jun;20(2):298-302
references: 21199039
references: Hypertension. 2007 Oct;50(4):693-700
references: 17785629
references: Arq Neuropsiquiatr. 2000 Mar;58(1):39-44
references: 10770864
references: Arch Intern Med. 2007 Feb 12;167(3):296-301
references: 17296887
references: J Neurosci. 2002 Oct 15;22(20):9005-14
references: 12388607
references: Physiol Behav. 2011 Oct 24;104(5):962-71
references: 21722658