title: Midlife managerial experience is linked to late life hippocampal morphology and function.
abstract: An active cognitive lifestyle has been suggested to have a protective role in the long-term maintenance of cognition. Amongst healthy older adults, more managerial or supervisory experiences in midlife are linked to a slower hippocampal atrophy rate in late life. Yet whether similar links exist in individuals with Mild Cognitive Impairment (MCI) is not known, nor whether these differences have any functional implications. 68 volunteers from the Sydney SMART Trial, diagnosed with non-amnestic MCI, were divided into high and low managerial experience (HME/LME) during their working life. All participants underwent neuropsychological testing, structural and resting-state functional MRI. Group comparisons were performed on hippocampal volume, morphology, hippocampal seed-based functional connectivity, memory and executive function and self-ratings of memory proficiency. HME was linked to better memory function (p = 0.024), mediated by larger hippocampal volume (p = 0.025). More specifically, deformation analysis found HME had relatively more volume in the CA1 sub-region of the hippocampus (p < 0.05). Paradoxically, this group rated their memory proficiency worse (p = 0.004), a result correlated with diminished functional connectivity between the right hippocampus and right prefrontal cortex (p < 0.001). Finally, hierarchical regression modelling substantiated this double dissociation.
authors.affiliation: School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Regenerative Neuroscience Group, Brain and Mind Research Institute, University of Sydney, Sydney, NSW, Australia.|Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Brain and Mental Health Laboratory, Monash Institute of Cognitive and Clinical Neurosciences, School of Psychological Science, Monash University, Clayton, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Suo
authors.affiliation: School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Regenerative Neuroscience Group, Brain and Mind Research Institute, University of Sydney, Sydney, NSW, Australia.|Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.
authors.forename: N
authors.initials: N
authors.lastname: Gates
authors.affiliation: Exercise Health and Performance Faculty Research Group, Faculty of Health Sciences and Sydney Medical School, The University of Sydney, Lidcombe, Australia.|Hebrew SeniorLife, Boston, MA, USA.|Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Fiatarone Singh
authors.affiliation: Exercise Health and Performance Faculty Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, Australia.
authors.forename: N
authors.initials: N
authors.lastname: Saigal
authors.affiliation: Exercise Health and Performance Faculty Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, Australia.
authors.forename: G C
authors.initials: GC
authors.lastname: Wilson
authors.affiliation: Exercise Health and Performance Faculty Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Meiklejohn
authors.affiliation: Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, NSW, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Sachdev
authors.affiliation: School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Dementia Collaborative Research Centre, University of New South Wales, Sydney, NSW, Australia.
authors.forename: H
authors.initials: H
authors.lastname: Brodaty
authors.affiliation: Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, NSW, Australia.
authors.forename: W
authors.initials: W
authors.lastname: Wen
authors.affiliation: Exercise Health and Performance Faculty Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, Australia.
authors.forename: N
authors.initials: N
authors.lastname: Singh
authors.affiliation: Department of Psychiatry, School of Medicine, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: B T
authors.initials: BT
authors.lastname: Baune
authors.affiliation: Exercise Health and Performance Faculty Research Group, Faculty of Health Sciences and Sydney Medical School, The University of Sydney, Lidcombe, Australia.|School of Exercise Science, Australian Catholic University, Strathfield, NSW, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Baker
authors.affiliation: Clinical and Rehabilitation Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, Australia.
authors.forename: N
authors.initials: N
authors.lastname: Foroughi
authors.affiliation: Hebrew SeniorLife, Boston, MA, USA.|Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA.|Department of Medicine and the Diabetes Center, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Psychiatry, University of New South Wales, Sydney, NSW, Australia. Michael.valenzuela@sydney.edu.au.|Regenerative Neuroscience Group, Brain and Mind Research Institute, University of Sydney, Sydney, NSW, Australia. Michael.valenzuela@sydney.edu.au.|Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, University of New South Wales, Sydney, NSW, Australia. Michael.valenzuela@sydney.edu.au.|Brain and Mind Centre, 100 Mallett St Camperdown, Sydney, NSW, 2050, Australia. Michael.valenzuela@sydney.edu.au.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Valenzuela
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology* / Q000502:physiology*; D001931:Brain Mapping; D004651:Employment; D056344:Executive Function / Q000502:physiology*; D005260:Female; D000070497:Healthy Lifestyle / Q000502:physiology; D006624:Hippocampus / Q000473:pathology* / Q000502:physiology*; D006801:Humans; D007857:Leadership; D008297:Male; D008875:Middle Aged; D009929:Organ Size / Q000502:physiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Cognitive lifestyle; Hippocampal functional connectivity; Hippocampal morphometry; Hippocampal volume; Managerial experience; Memory