title: Possible overlapping time frames of acquisition and consolidation phases in object memory processes: a pharmacological approach.
abstract: In previous studies, we have shown that acetylcholinesterase inhibitors and phosphodiesterase inhibitors (PDE-Is) are able to improve object memory by enhancing acquisition processes. On the other hand, only PDE-Is improve consolidation processes. Here we show that the cholinesterase inhibitor donepezil also improves memory performance when administered within 2 min after the acquisition trial. Likewise, both PDE5-I and PDE4-I reversed the scopolamine deficit model when administered within 2 min after the learning trial. PDE5-I was effective up to 45 min after the acquisition trial and PDE4-I was effective when administered between 3 and 5.5 h after the acquisition trial. Taken together, our study suggests that acetylcholine, cGMP, and cAMP are all involved in acquisition processes and that cGMP and cAMP are also involved in early and late consolidation processes, respectively. Most important, these pharmacological studies suggest that acquisition processes continue for some time after the learning trial where they share a short common time frame with early consolidation processes. Additional brain concentration measurements of the drugs suggest that these acquisition processes can continue up to 4-6 min after learning.
authors.affiliation: Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European Graduate School of Neuroscience.
authors.forename: Sven
authors.initials: S
authors.lastname: Akkerman
authors.affiliation: Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, European Graduate School of Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands.
authors.forename: Arjan
authors.initials: A
authors.lastname: Blokland
authors.affiliation: Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European Graduate School of Neuroscience jos.prickaerts@maastrichtuniversity.nl.
authors.forename: Jos
authors.initials: J
authors.lastname: Prickaerts
mesh_terms: D000818:Animals; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D004192:Discrimination, Psychological / Q000187:drug effects; D000077265:Donepezil; D007189:Indans / Q000494:pharmacology; D007858:Learning / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008568:Memory / Q000187:drug effects* / Q000502:physiology; D058986:Phosphodiesterase 5 Inhibitors / Q000494:pharmacology*; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D021641:Recognition, Psychology; D020889:Rolipram / Q000494:pharmacology; D012601:Scopolamine / Q000494:pharmacology; D000069058:Vardenafil Dihydrochloride / Q000494:pharmacology
chemical_list: D002800:Cholinesterase Inhibitors; D007189:Indans; D058986:Phosphodiesterase 5 Inhibitors; D010880:Piperidines; D000069058:Vardenafil Dihydrochloride; D000077265:Donepezil; D012601:Scopolamine; D020889:Rolipram