title: The impact of cognitive reserve on brain functional connectivity in Alzheimer's disease.
abstract: One factor believed to impact brain resilience to the pathological damage of Alzheimer's disease (AD) is the so-called "cognitive reserve" (CR). A critical issue that still needs to be fully understood is the mechanism by which environmental enrichment interacts with brain plasticity to determine resilience to AD pathology. Previous work using PET suggests that increased brain connectivity might be at the origin of the compensatory mechanisms implicated in this process. This study aims to further clarify this issue using resting-state functional MRI. Resting-state functional MRI was collected for 11 patients with AD, 18 with mild cognitive impairment (MCI), and 16 healthy controls, and analyzed to isolate the default mode network (DMN). A quantitative score of CR was obtained by combining information about number of years of education and type of schools attended. Consistent with previous reports, education was found to modulate functional connectivity in the posterior cingulate cortex, whose disconnection with the temporal lobes is known to be critical for the conversion from MCI to AD. This effect was highly significant in AD patients, less so in patients with MCI, and absent in healthy subjects. These findings show the potential neural mechanisms underlying the individual's ability to cope with brain damage, although they should be treated with some caution based on small numbers.
authors.affiliation: Neuroimaging Laboratory, IRCSS Santa Lucia, Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Bozzali
authors.affiliation: School of Life Sciences, University of Sussex, Brighton, United Kingdom.
authors.forename: Claire
authors.initials: C
authors.lastname: Dowling
authors.affiliation: Neuroimaging Laboratory, IRCSS Santa Lucia, Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Serra
authors.affiliation: Neuroimaging Laboratory, IRCSS Santa Lucia, Rome, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Spanò
authors.affiliation: Neuroimaging Laboratory, IRCSS Santa Lucia, Rome, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Torso
authors.affiliation: Institute of Neurology, Università Cattolica, Rome, Italy.
authors.forename: Camillo
authors.initials: C
authors.lastname: Marra
authors.affiliation: Neuroimaging Laboratory, IRCSS Santa Lucia, Rome, Italy Institute of Neurology, Università Cattolica, Rome, Italy.
authors.forename: Diana
authors.initials: D
authors.lastname: Castelli
authors.affiliation: Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Falmer, East Sussex, United Kingdom.
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Dowell
authors.affiliation: Department of Clinical Behavioural Neurology, IRCSS Santa Lucia Foundation, Rome, Italy Department of NeuroScience, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Koch
authors.affiliation: Department of Clinical Behavioural Neurology, IRCSS Santa Lucia Foundation, Rome, Italy Department of NeuroScience, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Caltagirone
authors.affiliation: Neuroimaging Laboratory, IRCSS Santa Lucia, Rome, Italy Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Falmer, East Sussex, United Kingdom.
authors.forename: Mara
authors.initials: M
authors.lastname: Cercignani
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications* / Q000473:pathology*; D001921:Brain / Q000098:blood supply / Q000473:pathology*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000209:etiology*; D058245:Cognitive Reserve / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008609:Mental Status Schedule; D009434:Neural Pathways / Q000098:blood supply / Q000473:pathology; D009483:Neuropsychological Tests
keywords: Alzheimer's disease; cognitive reserve; mild cognitive impairment; resting-state functional MRI