Related Experiment Videos
Cholinergic modulation of preattentive auditory processing in aging.
Eero Pekkonen1, Iiro P Jääskeläinen, Seppo Kaakkola
1Department of Neurology, University of Helsinki, PO Box 340, FIN-00029 HUS, Finland. eero.pekkoen@hus.fi
Neuroimage
|June 1, 2005
Summary
The cholinergic system impacts auditory processing in aging, with scopolamine delaying early auditory evoked potentials (P50, N100) in elderly individuals. This suggests a role for cholinergic modulation in stimulus detection during aging.
Area of Science:
- Neuroscience
- Auditory Neuroscience
- Aging Research
Background:
- Preattentive auditory processing, indexed by P50 and N100 ERPs, is crucial for stimulus detection.
- Aging is associated with impaired auditory processing and declining cholinergic activity.
- Scopolamine, a muscarinic antagonist, affects auditory processing in young adults, but its effect in the elderly is unclear.
Purpose of the Study:
- To investigate the effect of scopolamine on preattentive auditory processing in non-demented elderly subjects.
- To determine if cholinergic modulation of auditory evoked responses differs with age.
Main Methods:
- Simultaneous electroencephalogram (EEG) and magnetoencephalogram (MEG) recordings were used.
- Nine non-demented elderly subjects received intravenous scopolamine or glycopyrrolate (placebo) in a double-blind protocol.
- Auditory event-related potentials (ERPs) including P50, N100, MMN, and P200 were analyzed.
Main Results:
- Scopolamine significantly delayed electric P50 and both electric and magnetic N100 responses.
- Subsequent components, mismatch negativity (MMN) and P200, were not affected by scopolamine.
- Auditory evoked responses showed age-related sensitivity to cholinergic modulation.
Conclusions:
- The cholinergic system modulates auditory processing related to stimulus detection in aging.
- Combined MEG/EEG measurement of auditory N100 may serve as an objective marker for cholinergic activity in aging and Alzheimer's disease (AD).