Neurocognitive Plasticity Is Associated with Cardiorespiratory Fitness Following Physical Exercise in Older Adults with Amnestic Mild Cognitive Impairment

Abstract

Background: Aerobic training has been shown to promote structural and functional neurocognitive plasticity in cognitively intact older adults. However, little is known about the neuroplastic potential of aerobic exercise in individuals at risk of Alzheimer’s disease (AD) and dementia. Objective: We aimed to explore the effect of aerobic exercise intervention and cardiorespiratory fitness improvement on brain and cognitive functions in older adults with amnestic mild cognitive impairment (aMCI). Methods: 27 participants with aMCI were randomized to either aerobic training (n = 13) or balance and toning (BAT) control group (n = 14) for a 16-week intervention. Pre- and post-assessments included functional MRI experiments of brain activation during associative memory encoding and neural synchronization during complex information processing, cognitive evaluation using neuropsychological tests, and cardiorespiratory fitness assessment. Results: The aerobic group demonstrated increased frontal activity during memory encoding and increased neural synchronization in higher-order cognitive regions such as the frontal cortex and temporo-parietal junction (TPJ) following the intervention. In contrast, the BAT control group demonstrated decreased brain activity during memory encoding, primarily in occipital, temporal, and parietal areas. Increases in cardiorespiratory fitness were associated with increases in brain activation in both the left inferior frontal and precentral gyri. Furthermore, changes in cardiorespiratory fitness were also correlated with changes in performance on several neuropsychological tests. Conclusion: Aerobic exercise training may result in functional plasticity of high-order cognitive areas, especially, frontal regions, among older adults at risk of AD and dementia. Furthermore, cardiorespiratory fitness may be an important mediating factor of the observed changes in neurocognitive functions.

Neural Synchrony During Naturalistic Information Processing Is Associated With Aerobically Active Lifestyle and Cardiorespiratory Fitness in Cognitively Intact Older Adults

“…It was found that cognitively intact older adults demonstrate higher neural synchrony in higher order cognitive and linguistic regions compared to the aMCI patients. In addition, we have recently demonstrated the potential of aerobic exercise intervention in modifying inter-subject neural synchrony in these patients (Yogev-Seligmann et al, 2021 ). Interestingly, increases in inter-SC following the aerobic training intervention were demonstrated mainly in brain regions that were previously shown to exhibit compromised inter-subject neural synchrony compared to cognitively healthy older adults (Yogev-Seligmann et al, 2016 ).…”

“…Interestingly, the findings arising from these studies have suggested that aerobic exercise may be more beneficial to brain regions that are more affected during the aging process such as the prefrontal cortex (Raz et al, 2005 ; Raz and Rodrigue, 2006 ), the default mode network (DMN; Salami et al, 2014 ; Palmqvist et al, 2017 ), and the hippocampus (Raz et al, 2004 ; Langnes et al, 2020 ). For example, aerobic exercise has been associated with greater volume of the prefrontal cortex in cognitively intact older adults (Colcombe et al, 2006 ), and the preservation of higher-order functions that are mediated by this region such as executive and control abilities (Colcombe and Kramer, 2003 ; Yogev-Seligmann et al, 2021 ). Furthermore, aerobically active lifestyle and aerobic exercise interventions in this age group have also been linked to higher micro- and macro-structural integrity of the hippocampus and preserved episodic memory performance (Erickson et al, 2011 ; Eisenstein et al, 2021a ; Wilckens et al, 2021 ), although the effect of exercise on this region in humans is less consistent compared to that observed in animals (Wilckens et al, 2021 ).…”

Protocol for SYNchronising Exercises, Remedies in GaIt and Cognition at Home (SYNERGIC@Home): feasibility of a home-based double-blind randomised controlled trial to improve gait and cognition in individuals at risk for dementia

“…The control exercise will include balance and toning (BAT) exercises with equivalent time exposure but no progression. While evidence exists that BAT exercises can improve gait stability29 and strength,30 their effect on cognition is not demonstrated 31…”

“…While evidence exists that BAT exercises can improve gait stability 29 and strength, 30 their effect on cognition is not demonstrated. 31 …”

Staving Off Our Cognitive Decline: Another Benefit of All Those Hours in the Gym

“…FNBC, but improvement in cognitive performance was harder to determine. In a smaller study, Yogev-Seligmann et al 4 performed a study to prospectively evaluate neurocognitive plasticity. They randomized 27 patients with mild cognitive impairment to aerobic training or a balance and toning control intervention for 16 weeks and performed memory and neuropsychological testing.…”