LTP-like plasticity is impaired in amyloid-positive amnestic MCI but independent of PET-amyloid burden

• Published in: Neurobiology of aging Vol. 96; pp. 109 - 116
• Main Authors: Buss, Stephanie S., Press, Daniel Z., McDonald, Katherine, Kitchener, Erin, O'Connor, Margaret, Donohoe, Kevin, Shafi, Mouhsin M., Pascual-Leone, Alvaro, Fried, Peter J.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2020
• Subjects: Alzheimer's disease; Amyloid; Mild cognitive impairment; Plasticity; Transcranial magnetic stimulation; Amyloid; Transcranial magnetic stimulation; Mild cognitive impairment; Alzheimer's disease; Plasticity
• ISSN: 0197-4580; 1558-1497
• DOI: 10.1016/j.neurobiolaging.2020.08.021

Transcranial magnetic stimulation (TMS) reveals decreased efficacy of long-term potentiation-like (LTP-like) neuroplastic mechanisms in Alzheimer's disease (AD). However, it is not yet known whether LTP-like plasticity is also impaired in prodromal AD, or how abnormal TMS measures are related to established AD biomarkers. Here, we investigated the LTP-like response to intermittent theta-burst stimulation in 17 amyloid-positive participants with amnestic mild cognitive impairment (MCI) and 10 cognitively unimpaired controls. Our results showed a lack of LTP-like neuromodulation in MCI compared with controls that was unrelated to quantitative amyloid-beta burden on positron emission tomography. Surprisingly, greater LTP-like response was related to worse memory function in the MCI group, highlighting the complex role of neuroplasticity in the prodromal stages of AD. Overall, our results demonstrate abnormal LTP-like plasticity using intermittent theta-burst stimulation assessment in amyloid-positive participants with MCI. These findings support the potential for development of TMS measures as prognostic markers or therapeutic targets in early-stage symptomatic AD. •LTP-like plasticity is decreased in amnestic mild cognitive impairment (aMCI).•Amyloid burden on PET scan is not related to LTP-like plasticity in aMCI.•In amyloid-positive aMCI, the LTP-like response is inversely related to memory.