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

Article type: Research Article

Authors: Yogev-Seligmann, Galit^{a; b; 1; 2; *} | Eisenstein, Tamir^{a; b; 2} | Ash, Elissa^{a; c} | Giladi, Nir^{a; c; d} | Sharon, Haggai^{a; b; e; f} | Nachman, Shikma^b | Bregman, Noa^{a; c} | Kodesh, Einat^g | Hendler, Talma^{a; b; d; h} | Lerner, Yulia^{a; b; d}

Affiliations: [a] Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel | [b] Sagol Brain Institute, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel | [c] Department of Neurology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel | [d] Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel | [e] Pain Management & Neuromodulation Centre, Guy’s & St Thomas’ NHS Foundation Trust, London, UK | [f] Institute of Pain Medicine, Department of Anesthesiology and Critical Care Medicine, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel | [g] Department of Physical Therapy Faculty of Social Welfare & Health Sciences, University of Haifa, Haifa, Israel | [h] School of Psychological Sciences, Tel Aviv University, Tel Aviv, Israel

Correspondence: [*] Correspondence to: Galit Yogev-Seligmann, Department of Occupational Therapy, Faculty of Social Welfare& Health Sciences, University of Haifa, Haifa 3498838, Israel. Tel.:+972 4 8288390; Fax:+972 4 8249753; E-mail: [email protected].

Note: [1] Current affiliation: Department of Occupational Therapy, Faculty of Social Welfare & Health Sciences, University of Haifa, Israel.

Note: [2] These authors contributed equally to this work.

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 activationin 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.

Keywords: Brain plasticity, cardiorespiratory fitness, cognition, functional MRI, mild cognitive impairment, physical exercise

DOI: 10.3233/JAD-201429

Journal: Journal of Alzheimer's Disease, vol. 81, no. 1, pp. 91-112, 2021