Functional Connectivity Alterations in the Cholinergic Neural Circuits of Patients With Alzheimer’s Disease: A Donepezil Intervention Study Using Resting-State Functional Magnetic Resonance Imaging

BACKGROUND: Although donepezil alleviates Alzheimer's disease (AD) symptoms by raising acetylcholine levels, its impact on cholinergic pathways remains unclear. In this longitudinal, resting-state functional magnetic resonance imaging (rs-fMRI) study, we investigated donepezil-induced changes in cholinergic pathway networks in AD. METHODS: AD patients and healthy controls (HCs) were enrolled. AD patients received 24 weeks of donepezil treatment. Cognitive and emotional symptoms were assessed using the Mini-Mental State Examination (MMSE), Cornell Scale for Depression in Dementia (CSDD), and Neuropsychiatric Inventory (NPI) pre- and post-treatment. rs-fMRI was used to examine basal forebrain (BF) functional connectivity. RESULTS: Sixteen AD patients and 16 HCs completed the study. Post-treatment MMSE scores improved, and NPI and CSDD scores decreased. Reduced BF functional connectivity in the left cerebellar lobule VI, post-treatment, was revealed by rs-fMRI. Compared with HCs, post-treatment AD patients showed lower BF functional connectivity in the right postcentral gyrus (PoG); pre-treatment patients exhibited higher BF functional connectivity in the left cerebellar lobule VI. Right PoG functional connectivity was negatively correlated with disease duration pre-treatment and positively correlated with MMSE post-treatment. CONCLUSIONS: Donepezil improved clinical symptoms in AD by modulating the BF-PoG cholinergic pathway.