title: Memory encoding and dopamine in the aging brain: a psychopharmacological neuroimaging study.
abstract: Normal aging brings with it changes in dopaminergic and memory functions. However, little is known about how these 2 changes are related. In this study, we identify a link between dopamine, episodic memory networks, and aging, using pharmacological functional magnetic resonance imaging. Young and older adults received a D2-like agonist (Bromocriptine, 1.25 mg), a D2-like antagonist (Sulpiride, 400 mg), and Placebo, in a double-blind crossover procedure. We observed group differences, during memory encoding, in medial temporal, frontal, and striatal regions and moreover, these regions were differentially sensitive across groups to dopaminergic perturbation. These findings suggest that brain systems underlying memory show age-related changes and that dopaminergic function may be key in understanding these changes. That these changes have behavioral consequences was suggested by the observation that drug modulations were most pronounced in older subjects with poorer recognition memory. Our findings provide direct evidence linking ageing, memory, and dopaminergic change.
authors.affiliation: Department of Psychology and Centre for Cognitive and Neural Systems, University of Edinburgh, 1 George Square, Edinburgh EH8 9JZ, UK. alexa.morcom@ed.ac.uk
authors.forename: Alexa M
authors.initials: AM
authors.lastname: Morcom
authors.forename: Edward T
authors.initials: ET
authors.lastname: Bullmore
authors.forename: Felicia A
authors.initials: FA
authors.lastname: Huppert
authors.forename: Belinda
authors.initials: B
authors.lastname: Lennox
authors.forename: Asha
authors.initials: A
authors.lastname: Praseedom
authors.forename: Helen
authors.initials: H
authors.lastname: Linnington
authors.forename: Paul C
authors.initials: PC
authors.lastname: Fletcher
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000187:drug effects / Q000502:physiology*; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply / Q000187:drug effects / Q000502:physiology*; D001931:Brain Mapping; D018592:Cross-Over Studies; D004294:Domperidone / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000494:pharmacology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D008875:Middle Aged; D015233:Models, Statistical; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation / Q000379:methods; D011388:Prolactin / Q000097:blood; D055815:Young Adult
chemical_list: D018492:Dopamine Antagonists; D004294:Domperidone; D011388:Prolactin; D010100:Oxygen; D004298:Dopamine