Methods
This noninvasive brain stimulation method was used to measure both LTP-like plasticity and cholinergic function.
What is TMS?
Compared to younger adults, this neurophysiological measure declined in both older groups.
What is LTP-like plasticity?
This type of memory declined across immediate recall, delayed recall, and recognition in older adults.
What is episodic memory?
This neurotransmitter system, probed by SAI, is essential for attention and memory.
What is the cholinergic system?
Participants were divided into three groups: younger (18–30), older (60–70), and this group.
Who are adults aged 70–80?
In the study, motor evoked potentials (MEPs) were recorded from this muscle using EMG.
What is the abductor pollicis brevis (APB)?
A decline in SAI was only observed in this age group.
Who are adults aged 70–80 (OG-II)?
Older adults scored lower on this language test, reflecting word retrieval difficulties.
What is the Animal Fluency Test?
Increased density of these channels disrupts homeostasis and impairs LTP with age.
What are Ca²⁺ channels?
The study used this type of design, comparing groups rather than following them over time.
What is a cross-sectional design?
Which two cognitive screening tools were used to assess global cognition?
What are the MMSE and MoCA?
Older adults showed slower reaction times and more errors on this inhibitory control task.
What is the Go/No-Go task?
Declines in executive function and processing speed were detected with these two cognitive assessments.
What are the SDMT and Shape Trail Test?
Reduction of these receptor subunits reduces Ca²⁺ influx and weakens plasticity.
What are NMDA receptor subunits?
Participants completed cognitive assessments on the first day and these assessments on the second day.
What are neurophysiological assessments (TMS/iTBS & SAI)?
This TMS protocol was used to induce LTP-like plasticity.
What is intermittent theta burst stimulation (iTBS)?
Older adults had significantly lower accuracy on this working memory task.
What is the 1-back task?
Lower MoCA scores in older groups reflected impairments in these cognitive domains.
What are executive control, attention, and higher-order thinking?
This enzyme breaks down acetylcholine in the synaptic cleft.
What is acetylcholinesterase?
The small sample size of older participants limited this important aspect of statistical power.
What is generalizability / ability to detect effects?
SAI was measured using electrical stimulation of this nerve at the wrist.
What is the median nerve?
The 70–80 group also had lower baseline excitability, measured by reduced amplitudes of these responses.
What are MEPs (motor evoked potentials)?
Sentence formation and word finding failures were evident on this task, in addition to fluency decline.
What is the Boston Naming Test?
SAI effects are mediated by these two receptor types: one fast ion channel and one slower G-protein coupled receptor.
What are nicotinic and muscarinic receptors?
Because the design was cross-sectional, it risked being confounded by these factors (e.g., social, educational, environmental).
What are cohort effects?