Older adults’ episodic memory is related to a neurophysiological marker of brain cholinergic activity

• Published in: Experimental brain research Vol. 240; no. 9; pp. 2269 - 2276
• Main Authors: Davidson, Patrick S. R., Karpov, Galit, Giguère, Lauriane, Castro, Alex W., Tremblay, François
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2022; Springer; Springer Nature B.V
• Subjects: Acetylcholine; Aging; Biomedical and Life Sciences; Biomedicine; Brain research; Cholinergic mechanisms; Cognitive ability; Episodic memory; Executive function; Latency; Magnetic fields; Measuring techniques; Medical imaging; Memory; Memory in old age; Neuroimaging; Neurology; Neurosciences; Older people; Physiological aspects; Psychological aspects; Psychological research; Psychology; Research Article; Sensory neurons; Transcranial magnetic stimulation; Canada; Aging; Acetylcholine; Transcranial magnetic stimulation; Short-latency afferent inhibition; Episodic memory
• ISSN: 0014-4819; 1432-1106
• DOI: 10.1007/s00221-022-06420-9

Episodic memory is vulnerable to aging and may be influenced by age-related decline in the neurotransmitter acetylcholine. We probed this relation using a novel, minimally invasive transcranial magnetic stimulation marker of brain acetylcholine: short-latency afferent inhibition (SAI). We used neuropsychological testing to construct a composite score of episodic memory in N  = 19 community-dwelling older adults, and stratified older adults into Higher- ( N  = 9) versus Lower-memory ( N  = 10) groups before SAI. The Higher-memory group showed significantly stronger SAI than the Lower-memory group, indicating an association between higher brain acetylcholine levels and better episodic memory. The two memory groups were equivalent in the potential confounds of age, education, mood, subjective sleep quality, and executive function. These data converge with others to suggest that episodic memory is related to acetylcholine in older adults. This relation should be further investigated, especially with pharmacology and neuroimaging.