title: Transient anhedonia phenotype and altered circadian timing of behaviour during night-time dim light exposure in Per3-/-mice, but not wildtype mice.
abstract: Industrialisation greatly increased human night-time exposure to artificial light, which in animal models is a known cause of depressive phenotypes. Whilst many of these phenotypes are 'direct' effects of light on affect, an 'indirect' pathway via altered sleep-wake timing has been suggested. We have previously shown that the Period3 gene, which forms part of the biological clock, is associated with altered sleep-wake patterns in response to light. Here, we show that both wild-type and Per3-/-mice showed elevated levels of circulating corticosterone and increased hippocampal Bdnf expression after 3 weeks of exposure to dim light at night, but only mice deficient for the PERIOD3 protein (Per3-/-) exhibited a transient anhedonia-like phenotype, observed as reduced sucrose preference, in weeks 2-3 of dim light at night, whereas WT mice did not. Per3-/-mice also exhibited a significantly smaller delay in behavioural timing than WT mice during weeks 1, 2 and 4 of dim light at night exposure. When treated with imipramine, neither Per3-/-nor WT mice exhibited an anhedonia-like phenotype, and neither genotypes exhibited a delay in behavioural timing in responses to dLAN. While the association between both Per3-/-phenotypes remains unclear, both are alleviated by imipramine treatment during dim night-time light.
authors.affiliation: Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.|Department of Physiology, Federal University of Paraná, Curitiba, Paraná, Brazil.
authors.forename: Bruno Jacson
authors.initials: BJ
authors.lastname: Martynhak
authors.affiliation: Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.
authors.forename: Alexandra L
authors.initials: AL
authors.lastname: Hogben
authors.affiliation: Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.
authors.forename: Panos
authors.initials: P
authors.lastname: Zanos
authors.affiliation: Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.
authors.forename: Polymnia
authors.initials: P
authors.lastname: Georgiou
authors.affiliation: Department of Pharmacology, Federal University of Paraná, Curitiba, Paraná, Brazil.
authors.forename: Roberto
authors.initials: R
authors.lastname: Andreatini
authors.affiliation: Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.
authors.forename: Ian
authors.initials: I
authors.lastname: Kitchen
authors.affiliation: Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.
authors.forename: Simon N
authors.initials: SN
authors.lastname: Archer
authors.affiliation: Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.
authors.forename: Malcolm
authors.initials: M
authors.lastname: von Schantz
authors.affiliation: Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.|Institute of Medical and Biomedical Education, St George's University of London, UK.
authors.forename: Alexis
authors.initials: A
authors.lastname: Bailey
authors.affiliation: Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.
authors.forename: Daan R
authors.initials: DR
authors.lastname: van der Veen
mesh_terms: D059445:Anhedonia / Q000187:drug effects; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics; D057906:Circadian Clocks / Q000235:genetics*; D002940:Circadian Rhythm / Q000235:genetics* / Q000502:physiology; D005786:Gene Expression Regulation / Q000187:drug effects; D006624:Hippocampus / Q000378:metabolism / Q000502:physiology; D006801:Humans; D007099:Imipramine / Q000008:administration & dosage; D051379:Mice; D018345:Mice, Knockout; D009043:Motor Activity / Q000235:genetics / Q000502:physiology; D056950:Period Circadian Proteins / Q000235:genetics*; D017440:Photoperiod; D012890:Sleep / Q000235:genetics / Q000502:physiology; D012893:Sleep Wake Disorders / Q000188:drug therapy* / Q000235:genetics / Q000503:physiopathology
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C512645:Per3 protein, mouse; D056950:Period Circadian Proteins; D007099:Imipramine