title: Sleep is related to neuron numbers in the ventrolateral preoptic/intermediate nucleus in older adults with and without Alzheimer's disease.
abstract: Fragmented sleep is a common and troubling symptom in ageing and Alzheimer's disease; however, its neurobiological basis in many patients is unknown. In rodents, lesions of the hypothalamic ventrolateral preoptic nucleus cause fragmented sleep. We previously proposed that the intermediate nucleus in the human hypothalamus, which has a similar location and neurotransmitter profile, is the homologue of the ventrolateral preoptic nucleus, but physiological data in humans were lacking. We hypothesized that if the intermediate nucleus is important for human sleep, then intermediate nucleus cell loss may contribute to fragmentation and loss of sleep in ageing and Alzheimer's disease. We studied 45 older adults (mean age at death 89.2 years; 71% female; 12 with Alzheimer's disease) from the Rush Memory and Aging Project, a community-based study of ageing and dementia, who had at least 1 week of wrist actigraphy proximate to death. Upon death a median of 15.5 months later, we used immunohistochemistry and stereology to quantify the number of galanin-immunoreactive intermediate nucleus neurons in each individual, and related this to ante-mortem sleep fragmentation. Individuals with Alzheimer's disease had fewer galaninergic intermediate nucleus neurons than those without (estimate -2872, standard error = 829, P = 0.001). Individuals with more galanin-immunoreactive intermediate nucleus neurons had less fragmented sleep, after adjusting for age and sex, and this association was strongest in those for whom the lag between actigraphy and death was <1 year (estimate -0.0013, standard error = 0.0005, P = 0.023). This association did not differ between individuals with and without Alzheimer's disease, and similar associations were not seen for two other cell populations near the intermediate nucleus. These data are consistent with the intermediate nucleus being the human homologue of the ventrolateral preoptic nucleus. Moreover, they demonstrate that a paucity of galanin-immunoreactive intermediate nucleus neurons is accompanied by sleep fragmentation in older adults with and without Alzheimer's disease.
authors.affiliation: 1 Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada 2 Department of Neurology, Beth Israel Deaconess Medical Centre, Boston, MA, USA 3 Department of Neurology, Harvard Medical School, Boston, MA, USA.
authors.forename: Andrew S P
authors.initials: AS
authors.lastname: Lim
authors.affiliation: 2 Department of Neurology, Beth Israel Deaconess Medical Centre, Boston, MA, USA 3 Department of Neurology, Harvard Medical School, Boston, MA, USA.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Ellison
authors.affiliation: 2 Department of Neurology, Beth Israel Deaconess Medical Centre, Boston, MA, USA 3 Department of Neurology, Harvard Medical School, Boston, MA, USA.
authors.forename: Joshua L
authors.initials: JL
authors.lastname: Wang
authors.affiliation: 4 Rush Alzheimer's Disease Centre, Rush University, Chicago, IL, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
authors.affiliation: 4 Rush Alzheimer's Disease Centre, Rush University, Chicago, IL, USA.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Schneider
authors.affiliation: 4 Rush Alzheimer's Disease Centre, Rush University, Chicago, IL, USA.
authors.forename: Aron S
authors.initials: AS
authors.lastname: Buchman
authors.affiliation: 4 Rush Alzheimer's Disease Centre, Rush University, Chicago, IL, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Bennett
authors.affiliation: 2 Department of Neurology, Beth Israel Deaconess Medical Centre, Boston, MA, USA 3 Department of Neurology, Harvard Medical School, Boston, MA, USA csaper@bidmc.harvard.edu.
authors.forename: Clifford B
authors.initials: CB
authors.lastname: Saper
mesh_terms: D056044:Actigraphy; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D000544:Alzheimer Disease / Q000473:pathology* / Q000503:physiopathology; D002452:Cell Count; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D005260:Female; D019004:Galanin / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000473:pathology*; D011301:Preoptic Area / Q000473:pathology* / Q000503:physiopathology; D012146:Rest / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000473:pathology / Q000503:physiopathology; D012893:Sleep Wake Disorders / Q000473:pathology* / Q000503:physiopathology; D013493:Suprachiasmatic Nucleus / Q000254:growth & development / Q000473:pathology
chemical_list: D019004:Galanin
keywords: Alzheimer’s disease; human; hypothalamus; intermediate nucleus; sleep