Brain Health Across the Life Span Proceedings of a Workshop (2020) / Chapter Skim
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7 Brain Health Across the Life Span
7 Brain Health Across the Life Span
Pages 107-138
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From page 107... ...
• Electronic health records are already capturing important biologically based measures that could be easily scaled -- through mobile platforms or otherwise -- and then linked to meaningful health outcomes. Currently, differential treatment response to measures of brain health is a major gap in the lit erature that will need to be addressed to make this research clinically actionable.
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From page 108... ...
Ted Satterthwaite, assistant professor in the Department of Psychiatry at the University of Pennsylvania School of Medicine, examined how the integration of complex and personalized data can be used to understand normal and abnormal brain network development. Brain network aging and health across the adult life span was described by Gagan Wig, associate professor of behavioral and brain sciences at the Center for Vital Longevity at the University of Texas at Dallas.
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From page 109... ...
Carrying out similar research in humans is challenging, because the factors that drive the presence or absence of maternal support could also be contributing to brain development in children through genetic processes or other factors that are difficult to tease apart. However, available data in humans are consistent with the animal study data in suggesting that early experiences of maternal support -- or conversely, of abuse, neglect, or adversity -- also affect human hippocampal development (Bremner et al., 1997; Driessen et al., 2000; Stein et al., 1997)
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From page 110... ...
The findings for the longitudinal preschool study are consistent with the animal literature suggesting that early maternal support has a positive effect on hippocampal structure and function.2 The importance of larger hippocampal volume to emotional regulation was demonstrated when 2 Barch noted that animal models typically do not measure hippocampal volume; they tend to measure more molecular and cellular processes related to hippocampal development -- so the human and animal study results do not mirror each other exactly, but they are consistent.
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From page 111... ...
Steeper hippocampal volume growth was also associated with better episodic memory function in later adolescence. Adverse Childhood Experiences and Interactions with Maternal Support The outcome of the trajectory of hippocampal growth on later behaviors can be tied to early maternal support effects, said Barch.
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From page 112... ...
The estimated trajectories of hippocampal volume by preschool ACEs and school-age maternal support show that those two factors interact. For 3 Barch, D
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From page 113... ...
The largest amygdala volumes were associated with low preschool ACEs and high school-age maternal support, suggesting that both factors need to be present to optimize brain development. Not every brain region shows the same effect, however.
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From page 114... ...
Next, the investigators looked across the entire circuit of brain regions thought to be important for reward processing (including the dorsal and the ventral striatum, and the dorsal and rostral anterior cingulate versus specific brain regions) to see if it was related to a child's current depression versus cumulative level of depression.
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From page 115... ...
NOTE: ACE = adverse childhood experience. SOURCE: As presented by Deanna Barch at the workshop Brain Health Across the Life Span on September 25, 2019.
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From page 116... ...
The stronger effect is driven by the positive slope of having low ACEs and high maternal support. This was not exactly the pattern Barch's group predicted.
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From page 117... ...
This tends to happen in the absence of the more mature connections among amygdala, prefrontal cortex, and hippocampus that are seen later in adolescence and adulthood. This points to an early period when the nature of the neurobiology may be such that it is highly amenable to influences like individual variations in caregiving (Gabard-Durnam et al., 2014, 2016; Gee et al., 2013b; Silvers et al., 2016; Tottenham and Galván, 2016)
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From page 118... ...
It is a failure to receive needed parent–child intimacy, support, and serve–return dynamic, as well as being a significant stressor during brain development. When considering the role of stress during development, it
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From page 119... ...
. Amygdala Hyperactivity Reduces Developmental Plasticity Functional connectivity between the amygdala and medial prefrontal cortex reveals age-by-caregiving group interactions.
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From page 120... ...
NOTE: mPFC = medial prefrontal cortex. SOURCE: As presented by Nim Tottenham at the workshop Brain Health Across the Life Span on September 25, 2019.
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From page 121... ...
. Similarly, typically raised children showed a decrease in amygdala reactivity to their parents versus strangers that was not seen in children following institutional care.
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From page 122... ...
INTEGRATING COMPLEX AND PERSONALIZED DATA TO UNDERSTAND NORMAL AND ABNORMAL BRAIN NETWORK DEVELOPMENT Satterthwaite described two studies that integrate complex and personalized measures of network development throughout youth and adolescence with a focus on brain health. He explained that the rationale for studying brain development is increasingly clear.
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From page 123... ...
. Network Modularity as a Key Measure of Brain Health Satterthwaite used selection neuroimaging data from the PNC to focus on structural and functional brain networks.
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From page 124... ...
Instead, this project takes a discovery science approach using machine learning to define data-driven links between functional brain networks and psychiatric symptoms. He said that in essence, this "lets the brain teach us what the dimensions should be." He explained that typical functional networks use atlases with hundreds of nodes that cover the entire brain; when this is taken to a connectivity matrix, connections between each of these nodes can create a common network with tens of thousands of edges (Xia et al., 2018)
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From page 125... ...
Investigators found that the clinical item loadings accord with clinical experience, but they also cross diagnostic boundaries (Xia et al., 2018)
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From page 126... ...
SOURCES: As presented by Ted Satterthwaite at the workshop Brain Health Across the Life Span on September 25, 2019; Xia et al., 2018. genetic overlap between bipolar disorder and psychotic disorders.
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From page 127... ...
However, it is not yet understood how this individualized functional topography evolves in development or how it associates with important domains of healthy behavior, such as executive function. Nonnegative matrix factorization is a machine-learning technique that can be used for identifying brain networks in individuals (Li et al., 2018)
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From page 128... ...
. Children and adolescents who perform better in executive tasks have more total network representation allotted to systems that are important for executive function, like the frontoparietal control network and the ventral attention network.
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From page 129... ...
BRAIN NETWORK AGING AND HEALTH ACROSS THE ADULT LIFE SPAN Gagan Wig, associate professor of behavioral and brain sciences at the Center for Vital Longevity at the University of Texas at Dallas, presented on brain network aging and health across the adult life span, with a focus on novel measures of brain health. Even in the absence of disease, aging is associated with progressive changes in cognition (Park and ReuterLorenz, 2009)
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From page 130... ...
Differences in Brain Network Organization Across the Adult Life Span Evidence is emerging that resting-state brain networks in young adults are organized into communities -- described by Satterthwaite in terms of modularity -- that correspond to functionally distinct brain systems (Power et al., 2011)
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From page 131... ...
Additionally, his group has looked at whether system segregation is a reliable measure of an individual's brain network organization by using resting-state data from young adults collected on two different days, finding the measure to be strong enough that there is reason to believe it might be a useful way of thinking about individual-level network organization.
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From page 132... ...
132 FIGURE 7-5 Effect of aging on network segregation. SOURCES: As presented by Gagan Wig at the workshop Brain Health Across the Life Span on September 25, 2019; Chan et al., 2014.
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From page 133... ...
Modifiers of System Segregation Across the Adult Life Span Wig's group has also looked for other modifiers of system segregation across the adult life span, such as the role of the individual's environment, by using a bigger sample from the Dallas Lifespan Brain Study (Chan et al., 2018) .11 In adults, lower socioeconomic status (SES)
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From page 134... ...
SOURCES: As presented by Gagan Wig at the workshop Brain Health Across the Life Span on September 25, 2019; Chan et al., 2018. Future Research Directions Wig concluded by outlining a set of his group's future research directions.
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From page 135... ...
PANEL DISCUSSION ON THE WAY FORWARD IN MEASUREMENT AND RESEARCH Damien Fair, associate professor of behavioral neuroscience, associate professor of psychiatry, and associate scientist at the Advanced Imaging Research Center at the Oregon Health & Science University, asked the panelists to comment on the types of research needed to make the leap from the conceptual to the actionable in long-term brain health. Brain Health Growth Charts Barch highlighted a challenge in measuring the development and decline of brain health throughout the life span.
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From page 136... ...
Currently, differential treatment response to measures of brain health is a major gap in the literature that will need to be addressed to make this research clinically actionable. Building systems of informatics could also help to link biological measures to health outcomes.
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From page 137... ...
. Research on the biological bases of brain development and developing measures of brain health outcomes would be helpful in many ways, but there will always be individual variation, and this work should not preclude efforts to intervene on environmental factors that are known to influence brain development.
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From page 138... ...
Barch commented that there is a range of commonsense good practices that can improve brain health, such as exercise and sleep. However, she warned against framing that kind of information to imply incorrectly that it will prevent the occurrence of Alzheimer's disease or other brain disorders with underlying genetic factors.
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