Donepezil improves episodic memory in young individuals vulnerable to the effects of sleep deprivation.
OBJECTIVE
We investigated if donepezil, a long-acting orally administered cholinesterase inhibitor, would reduce episodic memory deficits associated with 24 h of sleep deprivation.


METHODS
Double-blind, placebo-controlled, crossover study involving 7 laboratory visits over 2 months. Participants underwent 4 functional MRI scans; 2 sessions (donepezil or placebo) followed a normal night's sleep, and 2 sessions followed a night of sleep deprivation.


METHODS
The study took place in a research laboratory.


METHODS
26 young, healthy volunteers with no history of any sleep, psychiatric, or neurologic disorders.


METHODS
5 mg of donepezil was taken once daily for approximately 17 days.


RESULTS
Subjects were scanned while performing a semantic judgment task and tested for word recognition outside the scanner 45 minutes later. Sleep deprivation increased the frequency of non-responses at encoding and impaired delayed recognition. No benefit of donepezil was evident when participants were well rested. When sleep deprived, individuals who showed greater performance decline improved with donepezil, whereas more resistant individuals did not benefit. Accompanying these behavioral effects, there was corresponding modulation of task-related activation in functionally relevant brain regions. Brain regions identified in relation to donepezil-induced alteration in non-response rates could be distinguished from regions relating to improved recognition memory. This suggests that donepezil can improve delayed recognition in sleep-deprived persons by improving attention as well as enhancing memory encoding.


CONCLUSIONS
Donepezil reduced decline in recognition performance in individuals vulnerable to the effects of sleep deprivation. Additionally, our findings demonstrate the utility of combined fMRI-behavior evaluation in psychopharmacological studies.
Chuah
Lisa Y M
LY
Cognitive Neuroscience Laboratory, Duke-NUS Graduate Medical School, Singapore.
Chong
Delise L
DL
Chen
Annette K
AK
Rekshan
William R
WR
Tan
Jiat-Chow
JC
Zheng
Hui
H
Chee
Michael W L
MW
D000284:Administration, Oral; D000328:Adult; D001143:Arousal / Q000187:drug effects; D001921:Brain / Q000187:drug effects*; D001931:Brain Mapping; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D018592:Cross-Over Studies; D004292:Dominance, Cerebral / Q000187:drug effects; D000077265:Donepezil; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007189:Indans / Q000494:pharmacology*; D008279:Magnetic Resonance Imaging; D008297:Male; D011939:Mental Recall / Q000187:drug effects*; D018697:Nootropic Agents / Q000494:pharmacology*; D010880:Piperidines / Q000494:pharmacology*; D011292:Premedication; D021641:Recognition, Psychology / Q000187:drug effects; D012892:Sleep Deprivation / Q000188:drug therapy* / Q000523:psychology; D014706:Verbal Learning / Q000187:drug effects; D055815:Young Adult
D002800:Cholinesterase Inhibitors; D007189:Indans; D018697:Nootropic Agents; D010880:Piperidines; D000077265:Donepezil