Comment on

• Sleep drives metabolite clearance from the adult brain.

  Xie L, Kang H, Xu Q, Chen MJ, Liao Y, Thiyagarajan M, O'Donnell J, Christensen DJ, Nicholson C, Iliff JJ, Takano T, Deane R, Nedergaard M. Xie L, et al. Science. 2013 Oct 18;342(6156):373-7. doi: 10.1126/science.1241224. Science. 2013. PMID: 24136970 Free PMC article.
• Modification of the relationship of the apolipoprotein E ε4 allele to the risk of Alzheimer disease and neurofibrillary tangle density by sleep.

  Lim AS, Yu L, Kowgier M, Schneider JA, Buchman AS, Bennett DA. Lim AS, et al. JAMA Neurol. 2013 Dec;70(12):1544-51. doi: 10.1001/jamaneurol.2013.4215. JAMA Neurol. 2013. PMID: 24145819 Free PMC article.
• Self-reported sleep and β-amyloid deposition in community-dwelling older adults.

  Spira AP, Gamaldo AA, An Y, Wu MN, Simonsick EM, Bilgel M, Zhou Y, Wong DF, Ferrucci L, Resnick SM. Spira AP, et al. JAMA Neurol. 2013 Dec;70(12):1537-43. doi: 10.1001/jamaneurol.2013.4258. JAMA Neurol. 2013. PMID: 24145859 Free PMC article.