Objective: To test the hypothesis that physical activity modifies the association between white matter hyperintensity (WMH) burden and motor function in healthy older persons without dementia.
Methods: Total daily activity (exercise and nonexercise physical activity) was measured for up to 11 days with actigraphy (Actical; Philips Respironics, Bend, OR) in 167 older adults without dementia participating in the Rush Memory and Aging Project. Eleven motor performances were summarized into a previously described global motor score. WMH volume was expressed as percent of intracranial volume. Linear regression models, adjusted for age, education, and sex, were performed with total WMH volume as the predictor and global motor score as the outcome. Terms for total daily physical activity and its interaction with WMH volume were then added to the model.
Results: Higher WMH burden was associated with lower motor function (p = 0.006), and total daily activity was positively associated with motor function (p = 0.002). Total daily activity modified the association between WMH and motor function (p = 0.007). WMH burden was not associated with motor function in persons with high activity (90th percentile). By contrast, higher WMH burden remained associated with lower motor function in persons with average (50th percentile; estimate = -0.304, slope = -0.133) and low (10th percentile; estimate = -1.793, slope = -0.241) activity.
Conclusions: Higher levels of physical activity may reduce the effect of WMH burden on motor function in healthy older adults.
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http://dx.doi.org/10.1212/WNL.0000000000001417 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720.
Norepinephrine in vertebrates and its invertebrate analog, octopamine, regulate the activity of neural circuits. We find that, when hungry, larvae switch activity in type II octopaminergic motor neurons (MNs) to high-frequency bursts, which coincide with locomotion-driving bursts in type I glutamatergic MNs that converge on the same muscles. Optical quantal analysis across hundreds of synapses simultaneously reveals that octopamine potentiates glutamate release by tonic type Ib MNs, but not phasic type Is MNs, and occurs via the G-coupled octopamine receptor (OAMB).
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January 2025
Chinese Academy of Sciences Key Laboratory of Tropical Marine Bio Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Innovation Academy of South China Sea Ecology and Environmental Engineering, Guangdong Provincial Observation and Research Station for Coastal Upwelling Ecosystem, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 511458, China.
Rotation of the bacterial flagellum, the first identified biological rotary machine, is driven by its stator units. Knowledge gained about the function of stator units has increasingly led to studies of rotary complexes in different cellular pathways. Here, we report that a tetrameric PilZ family protein, FlgX, is a structural component underneath the stator units in the flagellar motor of .
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405.
Dysregulation of GABAergic inhibition is associated with pathological pain. Consequently, enhancement of GABAergic transmission represents a potential analgesic strategy. However, therapeutic potential of current GABA agonists and modulators is limited by unwanted side effects.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan.
Many bacteria swim in liquid or swarm on surface using the flagellum rotated by a motor driven by specific ion flow. The motor consists of the rotor and stator, and the stator converts the energy of ion flow to mechanical rotation. However, the ion pathway and the mechanism of stator rotation coupled with specific ion flow are still obscure.
View Article and Find Full Text PDFPLoS Pathog
January 2025
Department of Microbiology, University of Georgia, Athens, Georgia, United States of America.
The Helicobacter pylori flagellar motor contains several accessory structures that are not found in the archetypal Escherichia coli and Salmonella enterica motors. H. pylori hp0838 encodes a previously uncharacterized lipoprotein and is in an operon with flgP, which encodes a motor accessory protein.
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