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Full-Text Articles in Medicine and Health Sciences
Cortical Iron Disrupts Functional Connectivity Networks Supporting Working Memory Performance In Older Adults, Valentinos Zachariou, Christopher E. Bauer, Elayna R. Seago, Flavius D. Raslau, David K. Powell, Brian T. Gold
Cortical Iron Disrupts Functional Connectivity Networks Supporting Working Memory Performance In Older Adults, Valentinos Zachariou, Christopher E. Bauer, Elayna R. Seago, Flavius D. Raslau, David K. Powell, Brian T. Gold
Neuroscience Faculty Publications
Excessive brain iron negatively affects working memory and related processes but the impact of cortical iron on task-relevant, cortical brain networks is unknown. We hypothesized that high cortical iron concentration may disrupt functional circuitry within cortical networks supporting working memory performance. Fifty-five healthy older adults completed an N-Back working memory paradigm while functional magnetic resonance imaging (fMRI) was performed. Participants also underwent quantitative susceptibility mapping (QSM) imaging for assessment of non-heme brain iron concentration. Additionally, pseudo continuous arterial spin labeling scans were obtained to control for potential contributions of cerebral blood volume and structural brain images were used to control …
Distinct Patterns Of Default Mode And Executive Control Network Circuitry Contribute To Present And Future Executive Function In Older Adults, Christopher A. Brown, Frederick A. Schmitt, Charles D. Smith, Brian T. Gold
Distinct Patterns Of Default Mode And Executive Control Network Circuitry Contribute To Present And Future Executive Function In Older Adults, Christopher A. Brown, Frederick A. Schmitt, Charles D. Smith, Brian T. Gold
Neuroscience Faculty Publications
Executive function (EF) performance in older adults has been linked with functional and structural profiles within the executive control network (ECN) and default mode network (DMN), white matter hyperintensities (WMH) burden and levels of Alzheimer's disease (AD) pathology. Here, we simultaneously explored the unique contributions of these factors to baseline and longitudinal EF performance in older adults. Thirty-two cognitively normal (CN) older adults underwent neuropsychological testing at baseline and annually for three years. Neuroimaging and AD pathology measures were collected at baseline. Separate linear regression models were used to determine which of these variables predicted composite EF scores at baseline …
Clinically Silent Alzheimer's And Vascular Pathologies Influence Brain Networks Supporting Executive Function In Healthy Older Adults, Brian T. Gold, Christopher A. Brown, Jonathan G. Hakun, Leslie M. Shaw, John Q. Trojanowski, Charles D. Smith
Clinically Silent Alzheimer's And Vascular Pathologies Influence Brain Networks Supporting Executive Function In Healthy Older Adults, Brian T. Gold, Christopher A. Brown, Jonathan G. Hakun, Leslie M. Shaw, John Q. Trojanowski, Charles D. Smith
Neuroscience Faculty Publications
Aging is associated with declines in executive function. We examined how executive functional brain systems are influenced by clinically silent Alzheimer’s disease (AD) pathology and cerebral white matter hyperintensities (WMHs). Twenty-nine younger adults and thirty-four cognitively normal older adults completed a working memory paradigm while functional magnetic resonance imaging (fMRI) was performed. Older adults further underwent lumbar cerebrospinal fluid (CSF) draw for assessment of AD pathology and FLAIR imaging for assessment of WMHs. Accurate working memory performance in both age groups was associated with high fronto-visual functional connectivity (fC). However, in older adults, higher expression of fronto-visual fC was linked …
Reduced Ability Of Calcitriol To Promote Augmented Dopamine Release In The Lesioned Striatum Of Aged Rats, Wayne A. Cass, Laura E. Peters
Reduced Ability Of Calcitriol To Promote Augmented Dopamine Release In The Lesioned Striatum Of Aged Rats, Wayne A. Cass, Laura E. Peters
Neuroscience Faculty Publications
Parkinson’s disease (PD) is a progressive and debilitating neurodegenerative disorder that affects over one million people in the United States. Previous studies, carried out in young adult rats, have shown that calcitriol, the active metabolite of vitamin D, can be neuroprotective in 6-hydroxydopamine (6-OHDA) models of PD. However, as PD usually affects older individuals, the ability of calcitriol to promote dopaminergic recovery was examined in lesioned young adult (4 month old), middle-aged (14 month old) and aged (22 month old) rats. Animals were given a single injection of 12 μg 6-OHDA into the right striatum. Four weeks later they were …
Age- And Sex-Related Changes In Fasting Plasma Glucose And Lipoprotein In Cynomolgus Monkeys, Feng Yue, Guodong Zhang, Rongping Tang, Zhouquan Zhang, Liqiong Teng, Zhiming Zhang
Age- And Sex-Related Changes In Fasting Plasma Glucose And Lipoprotein In Cynomolgus Monkeys, Feng Yue, Guodong Zhang, Rongping Tang, Zhouquan Zhang, Liqiong Teng, Zhiming Zhang
Neuroscience Faculty Publications
Background: The age-related dysfunction of glucose and lipid metabolism has a long-standing relationship with cardiovascular and neurodegenerative disease. However, the effects of metabolic dysfunction on men and women are different. Reasons for these sex differences remains unclear. Cynomolgus monkeys have been used, in the past, for the study of human metabolic diseases due to their biologically proximity to humans. Nevertheless, few studies to date have focused on both age- and sex-related differences in glucose and lipid metabolism. The present study was designed to specifically address these questions by using a large cohort of cynomolgus monkeys (N = 1,399) including …
White Matter Microstructure Contributes To Age-Related Declines In Task-Induced Deactivation Of The Default Mode Network, Christopher A. Brown, Jonathan G. Hakun, Zude Zhu, Nathan F. Johnson, Brian T. Gold
White Matter Microstructure Contributes To Age-Related Declines In Task-Induced Deactivation Of The Default Mode Network, Christopher A. Brown, Jonathan G. Hakun, Zude Zhu, Nathan F. Johnson, Brian T. Gold
Neuroscience Faculty Publications
Task-induced deactivations within the brain’s default mode network (DMN) are thought to reflect suppression of endogenous thought processes to support exogenous goal-directed task processes. Older adults are known to show reductions in deactivation of the DMN compared to younger adults. However, little is understood about the mechanisms contributing to functional dysregulation of the DMN in aging. Here, we explored the relationships between functional modulation of the DMN and age, task performance and white matter (WM) microstructure. Participants were 117 adults ranging from 25 to 83 years old who completed an fMRI task switching paradigm, including easy (single) and difficult (mixed) …
Lifelong Bilingualism Maintains Neural Efficiency For Cognitive Control In Aging, Brian T. Gold, Chobok Kim, Nathan F. Johnson, Richard J. Kryscio, Charles D. Smith
Lifelong Bilingualism Maintains Neural Efficiency For Cognitive Control In Aging, Brian T. Gold, Chobok Kim, Nathan F. Johnson, Richard J. Kryscio, Charles D. Smith
Neuroscience Faculty Publications
Recent behavioral data have shown that lifelong bilingualism can maintain youthful cognitive control abilities in aging. Here, we provide the first direct evidence of a neural basis for the bilingual cognitive control boost in aging. Two experiments were conducted, using a perceptual task-switching paradigm, including a total of 110 participants. In Experiment 1, older adult bilinguals showed better perceptual switching performance than their monolingual peers. In Experiment 2, younger and older adult monolinguals and bilinguals completed the same perceptual task-switching experiment while functional magnetic resonance imaging (fMRI) was performed. Typical age-related performance reductions and fMRI activation increases were observed. However, …