title: Alterations in dorsal and ventral posterior cingulate connectivity in APOEε4 carriers at risk of Alzheimer's disease.
abstract: BACKGROUND
  Recent evidence suggests that exercise plays a role in cognition and that the posterior cingulate cortex (PCC) can be divided into dorsal and ventral subregions based on distinct connectivity patterns.
  
  
  OBJECTIVE
  To examine the effect of physical activity and division of the PCC on brain functional connectivity measures in subjective memory complainers (SMC) carrying the epsilon 4 allele of apolipoprotein E (APOEε4) allele.
  
  
  METHODS
  Participants were 22 SMC carrying the APOEε4 allele (ε4+; mean age 72.18 years) and 58 SMC non-carriers (ε4-; mean age 72.79 years). Connectivity of four dorsal and ventral seeds was examined. Relationships between PCC connectivity and physical activity measures were explored.
  
  
  RESULTS
  ε4+ individuals showed increased connectivity between the dorsal PCC and dorsolateral prefrontal cortex, and the ventral PCC and supplementary motor area (SMA). Greater levels of physical activity correlated with the magnitude of ventral PCC-SMA connectivity.
  
  
  CONCLUSIONS
  The results provide the first evidence thatε4+ individuals at increased risk of cognitive decline show distinct alterations in dorsal and ventral PCC functional connectivity.
  
  
  BACKGROUND
  D.A. has served on scientific advisory boards for Novartis, Eli Lilly, Janssen, Prana and Pfizer, and as Editor-in-Chief forInternational Psychogeriatrics;received speaker honoraria from Pfizer and Lundbeck, and research support from Eli Lilly, GlaxoSmithKline, Forest Laboratories, Novartis, and CSIRO. C.L.M. has received consulting fees from Eli Lilly and Prana Biotechnology, and has stock ownership in Prana Biotechnology. C.C.R. has received consultancy payments from Roche and Piramal, and research support from Avid Radiopharmaceuticals, Eli Lilly, GE Healthcare, Piramal and Navidea for amyloid imaging. C.S. has provided clinical consultancy and been on scientific advisory committees for the Australian CSIRO, Alzheimer's Australia, University of Melbourne and other relationships, which are subject to confidentiality clauses; she has been a named Chief Investigator on investigator-driven collaborative research projects in partnership with Pfizer, Merck, Piramal, Bayer and GE Healthcare. Her research programme has received support from the National Health and Medical Research Council Alzheimer's Association, Collier Trust, Scobie and Claire McKinnon Foundation, JO and JR Wicking Trust, Shepherd Foundation, Brain Foundation, Mason Foundation, Ramaciotti Foundation, Alzheimer's Australia and the Royal Australian College of Physicians.
  © The Royal College of Psychiatrists 2015. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence.
authors.affiliation: , PhD, Department of Radiology, The Royal Melbourne Hospital, University of Melbourne, Parkville, Australia and Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Kerestes
authors.affiliation: , MBBS, FRANZCR.
authors.forename: Pramit M
authors.initials: PM
authors.lastname: Phal
authors.affiliation: , PhD.
authors.forename: Chris
authors.initials: C
authors.lastname: Steward
authors.affiliation: , PhD.
authors.forename: Bradford A
authors.initials: BA
authors.lastname: Moffat
authors.affiliation: , MSc (Eng), all at Department of Radiology, The Royal Melbourne Hospital, University of Melbourne, Parkville, Australia.
authors.forename: Simon
authors.initials: S
authors.lastname: Salinas
authors.affiliation: , PhD, School of Medicine and Pharmacology, University of Western Australia, Perth, Australia.
authors.forename: Kay L
authors.initials: KL
authors.lastname: Cox
authors.affiliation: , PhD, Academic Unit for Psychiatry of Old Age, St. Vincent's Health, Department of Psychiatry, University of Melbourne, Melbourne, Australia.
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Ellis
authors.affiliation: , PhD, National Ageing Research Institute, University of Melbourne, Parkville, Australia.
authors.forename: Elizabeth V
authors.initials: EV
authors.lastname: Cyarto
authors.affiliation: , MBBS, FRANZC, FRCPsych, Academic Unit for Psychiatry of Old Age, St Vincent's Health, Department of Psychiatry, University of Melbourne, Melbourne, Australia and National Ageing Research Institute, University of Melbourne, Parkville, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Ames
authors.affiliation: , PhD, School of Medical Sciences, Edith Cowan University, Perth, Australia.
authors.forename: Ralph N
authors.initials: RN
authors.lastname: Martins
authors.affiliation: , MD, The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia.
authors.forename: Colin L
authors.initials: CL
authors.lastname: Masters
authors.affiliation: , MD, FRACP, Department of Nuclear Medicine and Centre for PET, Austin Health, Heidelberg, Australia.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Rowe
authors.affiliation: , PhD, School of Health Sciences, University of Tasmania, Hobart, Australia.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Sharman
authors.affiliation: , PhD, Commonwealth Scientific Industrial Research Organization Preventative Health National Research Flagship, Australian e-Health Research Centre, Brisbane, Australia.
authors.forename: Olivier
authors.initials: O
authors.lastname: Salvado
authors.affiliation: , MBBS, FRACP, PhD.
authors.forename: Cassandra
authors.initials: C
authors.lastname: Szoeke
authors.affiliation: , MBBS, MPH, Mmed, National Ageing Research Institute, University of Melbourne, Parkville, Australia.
authors.forename: Michelle
authors.initials: M
authors.lastname: Lai
authors.affiliation: , MD, Academic Unit for Psychiatry of Old Age, St. Vincent's Health, Department of Psychiatry, University of Melbourne, Melbourne, Australia and North Western Mental Health, Melbourne Health, Melbourne, Australia.
authors.forename: Nicola T
authors.initials: NT
authors.lastname: Lautenschlager
authors.affiliation: , MD, Department of Radiology, The Royal Melbourne Hospital, University of Melbourne, Parkville, Australia.
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Desmond