ORCID Profile
0000-0002-8627-6192
Current Organisation
University College Cork APC Microbiome Institute
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Publisher: Elsevier BV
Date: 07-2020
Publisher: Wiley
Date: 27-09-2021
DOI: 10.1111/EJN.15467
Abstract: Neuroplasticity underpins motor learning, with abnormal neuroplasticity related to age‐associated motor declines. Bilateral transfer of motor learning, through rehabilitation, may mitigate these declines however, the magnitude of transfer may be reduced in older populations. This study investigated excitatory and inhibitory pathways in the trained and untrained hemispheres following unilateral training of a complex finger‐tapping task across ageing. Fifteen young (26.2 ± 3.8 years) and 11 older adults (63.7 ± 15.4 years) received transcranial magnetic stimulation, although surface electromyography was recorded from the extensor digitorum communis (EDC) and abductor pollicis brevis (APB), before and after practicing a complex finger‐tapping task with the dominant hand. Excitability, inhibition (expressed as percent change scores from pre‐ to post‐training), motor task performance and bilateral transfer were assessed between groups. Investigation of hemispheric differences within each group was completed for measures that significantly differed between groups. There were no between‐group differences in task performance or bilateral transfer, with task performance improving post‐training irrespective of group for both hands ( p 0.05). Pre‐ to post‐inhibition change scores of the untrained EDC muscle increased ( p = 0.034) in older compared with younger adults, indicating reduced inhibition in older adults. Inhibition change scores significantly differed between hemispheres for the young group only ( p = 0.037). Only the younger group presented with hemispheric lateralisation, providing some support for the Hemispheric Asymmetry Reduction in OLDer adults (HAROLD) hypothesis. Whether this reduction is evidence of de‐differentiation or compensation will need to be confirmed with additional measures.
Publisher: Frontiers Media SA
Date: 06-10-2016
Publisher: Informa UK Limited
Date: 18-11-2021
Publisher: Frontiers Media SA
Date: 30-03-2022
DOI: 10.3389/FMICB.2022.791213
Abstract: There is continued debate regarding Parkinson’s disease etiology and whether it originates in the brain or begins in the gut. Recently, evidence has been provided for both, with Parkinson’s disease onset presenting as either a “body-first” or “brain-first” progression. Most research indicates those with Parkinson’s disease have an altered gut microbiome compared to controls. However, some studies do not report gut microbiome differences, potentially due to the brain or body-first progression type. Based on the etiology of each proposed progression, in iduals with the body-first progression may exhibit altered gut microbiomes, i.e., where short-chain fatty acid producing bacteria are reduced, while the brain-first progression may not. Future microbiome research should consider this hypothesis and investigate whether gut microbiome differences exist between each type of progression. This may further elucidate the impact of the gut microbiome in Parkinson’s disease and show how it may not be homogenous across in iduals with Parkinson’s disease.
Publisher: MDPI AG
Date: 23-07-2022
Abstract: Poor motor function or physical performance is a predictor of cognitive decline. Additionally, slow gait speed is associated with poor cognitive performance, with gait disturbances being a risk factor for dementia. Parallel declines in muscular and cognitive performance (resulting in cognitive frailty) might be driven primarily by muscle deterioration, but bidirectional pathways involving muscle–brain crosstalk through the central and peripheral nervous systems are likely to exist. Following screening, early-stage parallel declines may be manageable and modifiable through simple interventions. Gait–brain relationships in dementia and the underlying mechanisms are not fully understood therefore, the current authors critically reviewed the literature on the gait–brain relationship and the underlying mechanisms and the feasibility/accuracy of assessment tools in order to identify research gaps. The authors suggest that dual-task gait is involved in concurrent cognitive and motor activities, reflecting how the brain allocates resources when gait is challenged by an additional task and that poor performance on dual-task gait is a predictor of dementia onset. Thus, tools or protocols that allow the identification of subtle disease- or disorder-related changes in gait are highly desirable to improve diagnosis. Functional near-infrared spectroscopy (fNIRS) is a non-invasive, cost-effective, safe, simple, portable, and non-motion-sensitive neuroimaging technique, widely used in studies of clinical populations such as people suffering from Alzheimer’s disease, depression, and other chronic neurological disorders. If fNIRS can help researchers to better understand gait disturbance, then fNIRS could form the basis of a cost-effective means of identifying people at risk of cognitive dysfunction and dementia. The major research gap identified in this review relates to the role of the central eripheral nervous system when performing dual tasks.
Publisher: Elsevier BV
Date: 05-2020
Publisher: Center for Open Science
Date: 09-06-2019
Abstract: The ability to supress inappropriate or unwanted behaviour, known as inhibition, can be indexed using a variety of task paradigms, one of the more common being the Go/No-go task. Studies in which popular neuroimaging methods such as functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) were used to measure neural activity during participant performance of the Go/No-go task have often identified ‘inhibitory-related’ activity in the right prefrontal cortex (PFC). While studies using functional near-infrared spectroscopy (fNIRS) have also identified changes in activity in the right PFC, the variants of the Go/No-go tasks previously employed in those studies have made it difficult to be confident that those changes measured using fNIRS were specifically related to inhibition. To determine whether the change in activity identified in the right PFC with fNIRS by previous studies using the Go/No-go task were indeed related to inhibition, we had participants complete three conditions of the Go/No-go task, each with varying levels of inhibitory demand (manipulated by the relative frequency of Go to No-go trials). We found that as Go-trial frequency increased, participants performed faster on Go-trials and less accurately on No-go trials. More importantly, as inhibitory-demand increased, activity in the right but not left PFC increased. When taken together, these findings are in support of the idea that the changes measured in the right PFC in earlier studies using fNIRS during the Go/No-go task were indeed related to inhibition.
Publisher: Elsevier BV
Date: 09-2023
Publisher: Elsevier BV
Date: 07-2019
No related grants have been discovered for Nathan Nuzum.