White-matter degradation and dynamical compensation support age-related functional alterations in human brain

Structural connectivity of the brain at different ages is analyzed using diffusion-weighted Magnetic Resonance Imaging (MRI) data. The largest decrease of the number and average length of stream- lines is found for the long inter-hemispheric links, with the strongest impact for frontal regions. From the BOLD functional MRI (fMRI) time series we identify age-related changes of dynamic functional connectivity (dFC) and spatial covariation features of the FC links captured by meta- connectivity (MC). They indicate more constant dFC, but wider range and variance of MC. Finally we applied computational whole-brain network model based on oscillators, which mechanistically expresses the impact of the spatio-temporal structure of the brain (weights and the delays) to the dynamics. With this we tested several hypothesis, which revealed that the spatio-temporal reorga- nization of the brain with ageing, supports the observed functional fingerprints only if the model accounts for: (i) compensation of the individual brains for the overall loss of structural connectivity, and (ii) decrease of propagation velocity due to the loss of myelination. We also show that having these two conditions, it is sufficient to decompose the time-delays as bimodal distribution that only distinguishes between intra- and inter-hemispheric delays, and that the same working point also captures the static FC the best.

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Mapping individual differences across brain network structure to function and behavior with connectome embedding

10.1101/2021.01.13.426513 ◽

2021 ◽

Author(s):

Gidon Levakov ◽

Joshua Faskowitz ◽

Galia Avidan ◽

Olaf Sporns

Keyword(s):

Individual Differences ◽

Functional Connectivity ◽

Predictive Accuracy ◽

Structural Connectivity ◽

Brain Regions ◽

Brain Network ◽

Global Network ◽

Age Related ◽

And Behavior ◽

The Brain

AbstractThe connectome, a comprehensive map of the brain’s anatomical connections, is often summarized as a matrix comprising all dyadic connections among pairs of brain regions. This representation cannot capture higher-order relations within the brain graph. Connectome embedding (CE) addresses this limitation by creating compact vectorized representations of brain nodes capturing their context in the global network topology. Here, nodes “context” is defined as random walks on the brain graph and as such, represents a generative model of diffusive communication around nodes. Applied to group-averaged structural connectivity, CE was previously shown to capture relations between inter-hemispheric homologous brain regions and uncover putative missing edges from the network reconstruction. Here we extend this framework to explore individual differences with a novel embedding alignment approach. We test this approach in two lifespan datasets (NKI: n=542; Cam-CAN: n=601) that include diffusion-weighted imaging, resting-state fMRI, demographics and behavioral measures. We demonstrate that modeling functional connectivity with CE substantially improves structural to functional connectivity mapping both at the group and subject level. Furthermore, age-related differences in this structure-function mapping are preserved and enhanced. Importantly, CE captures individual differences by out-of-sample prediction of age and intelligence. The resulting predictive accuracy was higher compared to using structural connectivity and functional connectivity. We attribute these findings to the capacity of the CE to incorporate aspects of both anatomy (the structural graph) and function (diffusive communication). Our novel approach allows mapping individual differences in the connectome through structure to function and behavior.

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The Impact of Bone on the Biology of Aging

Innovation in Aging ◽

10.1093/geroni/igaa057.2643 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

pp. 740-740

Author(s):

Gerard Karsenty

Keyword(s):

Muscle Function ◽

Male Fertility ◽

Leydig Cells ◽

Memory Loss ◽

Age Related ◽

Systematic Exploration ◽

Biology Of Aging ◽

The Impact ◽

The Brain ◽

Regulate Energy Metabolism

Abstract We hypothesized that bone may secrete hormones that regulate energy metabolism and reproduction. Testing this hypothesis revealed that the osteoblast-specific secreted protein osteocalcin is a hormone regulating glucose homeostasis and male fertility by signaling through a GPCR, Gprc6a, expressed in pancreatic β bells and Leydig cells of the testes. The systematic exploration of osteocalcin biology, revealed that it regulates an unexpectedly large spectrum of physiological functions in the brain and peripheral organs and that it has most features of an antigeromic molecule. As will be presented at the meeting, this body of work suggests that harnessing osteocalcin for therapeutic purposes may be beneficial in the treatment of age-related diseases such as depression, age-related memory loss and the decline in muscle function seen in sarcopenia.

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Coaching skills for recovery a decade of providing coaching skills for recovery training at a healthcare NHS foundation trust

Mental Health and Social Inclusion ◽

10.1108/mhsi-11-2020-0076 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Helen Kathryn Cyrus

Keyword(s):

Work Practice ◽

Clinical Approach ◽

Personal Recovery ◽

Content Type ◽

Coaching Skills ◽

The Difference ◽

To Come ◽

The Individual ◽

The Impact ◽

The Brain

Purpose Overview of coaching for recovery. The paper aims to show an overview of work that was carried out over 11 years with groups of mental health and physical staff. As the facilitator who had run this course for the duration in Nottingham, this was an excellent opportunity to be at the forefront of a brand new project. Design/methodology/approach The introduction of the skills are taught over two consecutive days followed by a further day a month later. The idea of coaching is to be enabled to find the answers in themselves by the use of powerful questions and using the technique of the grow model, combined with practice enables the brain to come up with its own answers. Using rapport and enabling effective communication to deliver the outcome. Findings Evidence from staff/clients and the purpose of the paper shows that when you step back it allows the individual patients/staff to allow the brain to process to create to come up with their solutions, which then helps them to buy into the process and creates ownership. Research limitations/implications The evidence suggests that the approach that was there prior to the course was very much a clinical approach to working with clients and treating the person, administering medication and not focussing on the inner person or personal recovery. The staff review has shown that in the clinical context change is happening from the inside out. Practical implications “Helps change culture”; “change of work practice”; “it changed staff focus – not so prescriptive”; “powerful questions let clients come to their own conclusions”; “coaching gives the ability to find half full. Helps to offer reassurance and to find one spark of hope”. Social implications This has shown that the approach is now person-centred/holistic. This has been the “difference that has made the difference”. When this paper looks at the issues from a different angle in this case a coaching approach, applying technique, knowledge and powerful questions the results have changed. The same clients, same staff and same problems but with the use of a different approach, there is the evidence of a different outcome, which speaks for itself. The coaching method is more facilitative, therefore it illicit’s a different response, and therefore, result. Originality/value The results/evidence starts with the individual attending and their commitment to the process over the two-day course. Then going away for the four weeks/six for managers and a commitment again to practice. Returning to share the impact if any with the group. This, in turn, helps to inspire and gain motivation from the feedback to go back to work invigorated to keep going.

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Dynamic Properties of Simulated Brain Network Models and Empirical Resting State Data

10.1101/344473 ◽

2018 ◽

Author(s):

Amrit Kashyap ◽

Shella Keilholz

Keyword(s):

Resting State ◽

Dynamic Properties ◽

Brain Activity ◽

Temporal Structure ◽

Structural Connectivity ◽

Network Models ◽

Resting State Fmri ◽

Brain Network ◽

Dynamical Analysis ◽

Whole Brain

AbstractBrain Network Models have become a promising theoretical framework in simulating signals that are representative of whole brain activity such as resting state fMRI. However, it has been difficult to compare the complex brain activity between simulated and empirical data. Previous studies have used simple metrics that surmise coordination between regions such as functional connectivity, and we extend on this by using various different dynamical analysis tools that are currently used to understand resting state fMRI. We show that certain properties correspond to the structural connectivity input that is shared between the models, and certain dynamic properties relate more to the mathematical description of the Brain Network Model. We conclude that the dynamic properties that gauge more temporal structure rather than spatial coordination in the rs-fMRI signal seem to provide the largest contrasts between different BNMs and the unknown empirical dynamical system. Our results will be useful in constraining and developing more realistic simulations of whole brain activity.

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A three-step model of stress management for health leaders

Healthcare Management Forum ◽

10.1177/0840470417751157 ◽

2018 ◽

Vol 31 (3) ◽

pp. 81-86

Author(s):

Elizabeth Hartney

Keyword(s):

Nervous System ◽

Stress Management ◽

Healthcare System ◽

Stressful Environment ◽

Step Model ◽

System Functioning ◽

Managing Stress ◽

The Individual ◽

The Impact ◽

The Brain

The current healthcare system is often as highly stressful environment for patients, their families, and for the employees of the system. Health leaders also experience stress, which can have profound repercussions if not well managed. This article describes the impact of stress on the brain and nervous system functioning of health leaders, then, drawing on evidence from the literature, presents a three-step model for managing stress at the individual, team/organizational, and system levels.

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Examining the nervous system of an older patient

Oxford Textbook of Geriatric Medicine ◽

10.1093/med/9780198701590.003.0111_update_001 ◽

2017 ◽

pp. 865-870

Author(s):

Henry J. Woodford ◽

James George

Keyword(s):

Nervous System ◽

White Matter Lesions ◽

Clinical Situation ◽

Neurological Assessment ◽

Risk Of Death ◽

Age Related ◽

Power Testing ◽

The Individual ◽

The Brain ◽

Age Related Changes

Ageing is associated with changes in the nervous system, especially the accumulation of neurodegenerative and white matter lesions within the brain. Abnormalities are commonly found when examining older people and some of these are associated with functional impairment and a higher risk of death. In order to reliably interpret examination findings it is important to assess cognition, hearing, vision, and speech first. Clarity of instruction is key. Interpretation of findings must take into account common age-related changes. For example, genuine increased tone should be distinguished from paratonia. Power testing should look for asymmetry within the individual, rather than compare to the strength of the examiner. Parkinsonism should be looked for and gait should be observed. Neurological assessment can incorporate a range of cortical abilities and tests of autonomic function, but the extent of these assessments is likely to be determined by the clinical situation and time available.

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Prediction of motor recovery using indirect connectivity in a lesion network after ischemic stroke

Therapeutic Advances in Neurological Disorders ◽

10.1177/1756286420925679 ◽

2020 ◽

Vol 13 ◽

pp. 175628642092567

Author(s):

Jungsoo Lee ◽

Eunhee Park ◽

Ahee Lee ◽

Won Hyuk Chang ◽

Dae-Shik Kim ◽

...

Keyword(s):

Prediction Model ◽

Motor Function ◽

Brain Network ◽

Reference Network ◽

Lesion Volume ◽

Motor Impairments ◽

Rehabilitation Programs ◽

Time Courses ◽

The Impact ◽

The Brain

Background: Recovery prediction can assist in the planning for impairment-focused rehabilitation after a stroke. This study investigated a new prediction model based on a lesion network analysis. To predict the potential for recovery, we focused on the next link-step connectivity of the direct neighbors of a lesion. Methods: We hypothesized that this connectivity would contribute to recovery after stroke onset. Each lesion in a patient who had suffered a stroke was transferred to a healthy subject. First link-step connectivity was identified by observing voxels functionally connected to each lesion. Next (second) link-step connectivity of the first link-step connectivity was extracted by calculating statistical dependencies between time courses of regions not directly connected to a lesion and regions identified as first link-step connectivity. Lesion impact on second link-step connectivity was quantified by comparing the lesion network and reference network. Results: The lower the impact of a lesion was on second link-step connectivity in the brain network, the better the improvement in motor function during recovery. A prediction model containing a proposed predictor, initial motor function, age, and lesion volume was established. A multivariate analysis revealed that this model accurately predicted recovery at 3 months poststroke ( R 2 = 0.788; cross-validation, R 2 = 0.746, RMSE = 13.15). Conclusion: This model can potentially be used in clinical practice to develop individually tailored rehabilitation programs for patients suffering from motor impairments after stroke.

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Mindfulness Meditation Is Related to Long-Lasting Changes in Hippocampal Functional Topology during Resting State: A Magnetoencephalography Study

Neural Plasticity ◽

10.1155/2018/5340717 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 9

Author(s):

Anna Lardone ◽

Marianna Liparoti ◽

Pierpaolo Sorrentino ◽

Rosaria Rucco ◽

Francesca Jacini ◽

...

Keyword(s):

Resting State ◽

Mindfulness Meditation ◽

Brain Connectivity ◽

Brain Networks ◽

Brain Network ◽

Long Term Effects ◽

Age Related ◽

Functional Topology ◽

The Right ◽

The Brain

It has been suggested that the practice of meditation is associated to neuroplasticity phenomena, reducing age-related brain degeneration and improving cognitive functions. Neuroimaging studies have shown that the brain connectivity changes in meditators. In the present work, we aim to describe the possible long-term effects of meditation on the brain networks. To this aim, we used magnetoencephalography to study functional resting-state brain networks in Vipassana meditators. We observed topological modifications in the brain network in meditators compared to controls. More specifically, in the theta band, the meditators showed statistically significant (p corrected = 0.009) higher degree (a centrality index that represents the number of connections incident upon a given node) in the right hippocampus as compared to controls. Taking into account the role of the hippocampus in memory processes, and in the pathophysiology of Alzheimer’s disease, meditation might have a potential role in a panel of preventive strategies.

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Approximate Entropy of Brain Network in the Study of Hemispheric Differences

Entropy ◽

10.3390/e22111220 ◽

2020 ◽

Vol 22 (11) ◽

pp. 1220

Author(s):

Francesca Alù ◽

Francesca Miraglia ◽

Alessandro Orticoni ◽

Elda Judica ◽

Maria Cotelli ◽

...

Keyword(s):

Brain Networks ◽

Approximate Entropy ◽

Brain Network ◽

Hemispheric Differences ◽

Eyes Closed ◽

Age Related ◽

Eeg Recordings ◽

The Right ◽

The Impact ◽

Adult Volunteers

Human brain, a dynamic complex system, can be studied with different approaches, including linear and nonlinear ones. One of the nonlinear approaches widely used in electroencephalographic (EEG) analyses is the entropy, the measurement of disorder in a system. The present study investigates brain networks applying approximate entropy (ApEn) measure for assessing the hemispheric EEG differences; reproducibility and stability of ApEn data across separate recording sessions were evaluated. Twenty healthy adult volunteers were submitted to eyes-closed resting EEG recordings, for 80 recordings. Significant differences in the occipital region, with higher values of entropy in the left hemisphere than in the right one, show that the hemispheres become active with different intensities according to the performed function. Besides, the present methodology proved to be reproducible and stable, when carried out on relatively brief EEG epochs but also at a 1-week distance in a group of 36 subjects. Nonlinear approaches represent an interesting probe to study the dynamics of brain networks. ApEn technique might provide more insight into the pathophysiological processes underlying age-related brain disconnection as well as for monitoring the impact of pharmacological and rehabilitation treatments.

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