title: Multi-modal characterization of rapid anterior hippocampal volume increase associated with aerobic exercise.
abstract: The hippocampus has been shown to demonstrate a remarkable degree of plasticity in response to a variety of tasks and experiences. For example, the size of the human hippocampus has been shown to increase in response to aerobic exercise. However, it is currently unknown what underlies these changes. Here we scanned sedentary, young to middle-aged human adults before and after a six-week exercise intervention using nine different neuroimaging measures of brain structure, vasculature, and diffusion. We then tested two different hypotheses regarding the nature of the underlying changes in the tissue. Surprisingly, we found no evidence of a vascular change as has been previously reported. Rather, the pattern of changes is better explained by an increase in myelination. Finally, we show that hippocampal volume increase is temporary, returning to baseline after an additional six weeks without aerobic exercise. This is the first demonstration of a change in hippocampal volume in early to middle adulthood suggesting that hippocampal volume is modulated by aerobic exercise throughout the lifespan rather than only in the presence of age related atrophy. It is also the first demonstration of hippocampal volume change over a period of only six weeks, suggesting that gross morphometric hippocampal plasticity occurs faster than previously thought.
authors.affiliation: Section on Functional Imaging Methods, NIMH, NIH, DHHS, Bethesda, MD, USA; FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom. Electronic address: adamt@nih.gov.
authors.forename: Adam G
authors.initials: AG
authors.lastname: Thomas
authors.affiliation: FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Andrea
authors.initials: A
authors.lastname: Dennis
authors.affiliation: FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Nancy B
authors.initials: NB
authors.lastname: Rawlings
authors.affiliation: FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Charlotte J
authors.initials: CJ
authors.lastname: Stagg
authors.affiliation: FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Lucy
authors.initials: L
authors.lastname: Matthews
authors.affiliation: Movement Sciences Group, Oxford Brookes University, Oxford, United Kingdom.
authors.forename: Martyn
authors.initials: M
authors.lastname: Morris
authors.affiliation: Center for Neuroimaging Sciences, King's College London, London, ON, Canada.
authors.forename: Shannon H
authors.initials: SH
authors.lastname: Kolind
authors.affiliation: FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Sean
authors.initials: S
authors.lastname: Foxley
authors.affiliation: FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Jenkinson
authors.affiliation: Department of Statistics, University of Warwick, Coventry, United Kingdom.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Nichols
authors.affiliation: Department of Statistics, University of Warwick, Coventry, United Kingdom.
authors.forename: Helen
authors.initials: H
authors.lastname: Dawes
authors.affiliation: Section on Functional Imaging Methods, NIMH, NIH, DHHS, Bethesda, MD, USA.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Bandettini
authors.affiliation: FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Heidi
authors.initials: H
authors.lastname: Johansen-Berg
mesh_terms: D000328:Adult; D000375:Aging / Q000473:pathology / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006624:Hippocampus / Q000033:anatomy & histology / Q000502:physiology*; D006801:Humans; D008297:Male; D064847:Multimodal Imaging / Q000379:methods; D059906:Neuroimaging / Q000379:methods*; D009473:Neuronal Plasticity / Q000502:physiology*; D009929:Organ Size / Q000502:physiology; D064797:Physical Conditioning, Human / Q000379:methods
keywords: Aging; Angiogenesis; Dentate gyrus; Environmental enrichment; Exercise; Fitness; Hippocampus; Myelin; Neurogenesis; Plasticity