title: Tacrine improves reversal learning in older rats.
abstract: Age-related decline has been reported in most cognitive domains, including executive function: in particular, attentional set-shifting and reversal learning, as measures of executive control, are impaired in aged populations of both humans and rats. Despite the importance of the cholinergic system in age-related cognitive decline, no data are available on the effects of cholinergic enhancement on age-related performance deficits in tests of attentional set-shifting. We investigated the effects of the cholinesterase inhibitor tetrahydroacridin-9-amine (tacrine) on reversal learning and attentional set-shifting in older rats (aged 16-21 months) using the rodent version of the intradimensional/extradimensional attentional set-shifting task in a repeated-measures design. Discrimination acquisition was not impaired, but age-related impairments in reversal learning were persistent between tests, and ameliorated by the 3 mg/kg dose of tacrine. No age-related impairments in set-shifting were seen, but there was a tendency for tacrine to reduce the cost of shifting set. Given the lack of previous evidence for a role of cortical acetylcholine in attentional set-shifting tasks, it is likely that altered neurotransmitter interactions in striatum underlie this improvement.
authors.affiliation: School of Psychology and Neuroscience, University of St Andrews, St Mary's College, South Street, St Andrews, Fife, Scotland KY16 9JP, UK.
authors.forename: David S
authors.initials: DS
authors.lastname: Tait
authors.forename: E Alexander
authors.initials: EA
authors.lastname: Chase
authors.forename: Verity J
authors.initials: VJ
authors.lastname: Brown
mesh_terms: D000375:Aging / Q000187:drug effects*; D000818:Animals; D001288:Attention / Q000187:drug effects; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D008297:Male; D051381:Rats; D012193:Reversal Learning / Q000187:drug effects*; D013619:Tacrine / Q000494:pharmacology*
chemical_list: D002800:Cholinesterase Inhibitors; D013619:Tacrine
keywords: Acetylcholine; Aging; Attentional set-shifting; Reversal learning; Tacrine