Anticholinergic Amnesia is Mediated by Alterations in Human Network Connectivity Architecture

Area of Science:

• Neuroscience
• Pharmacology
• Cognitive Science

Background:

• Cholinergic neurotransmission is crucial for memory and implicated in Alzheimer's disease, delirium, and drug-induced memory deficits.
• Anticholinergic drugs may disrupt memory by altering neural network function.

Purpose of the Study:

• To investigate how anticholinergic drug administration affects episodic memory and functional brain network architecture.
• To explore the role of specific brain networks in scopolamine-induced memory impairment.

Main Methods:

• A double-blind, crossover study using functional connectivity magnetic resonance imaging (fcMRI).
• Clinically normal elderly participants received low-dose scopolamine (0.2 mg IV).
• Episodic memory performance and functional connectivity were assessed.

Main Results:

• Scopolamine decreased episodic memory performance.
• Connectivity strength was selectively reduced in 3 of 7 cortical networks.
• Disrupted connectivity within the Default and Salience networks mediated memory effects, independent of amyloid burden.

Conclusions:

• Scopolamine-induced amnesia is linked to disrupted functional connectivity within and between the Default and Salience networks.
• These findings highlight the importance of these networks for memory performance.
• Functional connectivity MRI is a valuable tool for studying the systems-level effects of psychoactive drugs.