ABSTRACT
INTRODUCTION: Aging is associated with cholinergic hypofunction and memory decline. Cholinergic activity also plays a crucial role in sleep-dependent memory consolidation. The acetylcholinesterase inhibitor (AChE-I) donepezil has been found to increase sleep-related procedural memory consolidation in healthy older adults in a previous study. METHODS: Data of the former study were reanalyzed with regard to the effects of donepezil on the sleep EEG of healthy older adults. This analysis was conducted with a special focus on spectral parameters of sleep, which have previously been linked to plasticity-related processes during sleep, i.e., sigma and delta activity. Forty-two participants (aged: 60-77 years) received 5 mg of the AChE-I donepezil orally 30 min before bedtime in a placebo-controlled, double-blind design. Power values for EEG delta, theta, alpha1, alpha 2, sigma, beta and gamma frequency bands were calculated for stage 2 NREM sleep, SWS and REM sleep. RESULTS: In line with our hypotheses, the AChE-I donepezil led to an increase in sigma activity during stage 2 NREM sleep and delta activity during slow wave sleep. CONCLUSION: These results suggest that an AChE-I facilitates processes of sleep-dependent memory consolidation in older adults.
Subject(s)
Cholinesterase Inhibitors/administration & dosage , Electroencephalography , Geriatric Assessment , Indans/administration & dosage , Piperidines/administration & dosage , Sleep/drug effects , Administration, Oral , Aged , Aged, 80 and over , Donepezil , Double-Blind Method , Electroencephalography/classification , Electroencephalography/drug effects , Female , Humans , Male , Middle Aged , Sleep/physiology , Sleep Stages/drug effects , Spectrum AnalysisABSTRACT
INTRODUCTION: Previous research in younger individuals has shown that acetylcholinesterase inhibitors tend to enhance REM sleep. METHODS: Forty-two healthy elderly persons participated in a double-blind placebo-controlled polysomnographic study (parallel group design). RESULTS: The present study indicates that in the elderly persons, donepezil, an acetylcholinesterase inhibitor also exerts a marked effect on REM sleep parameters: REM density was increased whereas REM latency was reduced, thus, confirming the findings of our pilot study described earlier. CONCLUSION: Whether the cholinergic stimulation measured by polysomnography is related to treatment efficacy is a very interesting but an open question. Based on the findings that REM sleep is associated with memory consolidation, the question whether REM sleep augmentation enhances memory performance-as suggested by the findings of the pilot study-seems to be an interesting topic for future research.
