scholarly journals Stimulus transformation into motor action: dynamic graph analysis reveals a posterior-to-anterior shift in brain network communication of older subjects

2020 ◽  
Author(s):  
Nils Rosjat ◽  
Bin A. Wang ◽  
Liqing Liu ◽  
Gereon R. Fink ◽  
Silvia Daun
Keyword(s):  
Age Groups ◽  
Brain Network ◽  
Hemispheric Lateralization ◽  
Dynamic Graph ◽  
Movement Initiation ◽  
Motor Action ◽  
Low Frequencies ◽  
Functional Changes ◽  
Age Related ◽  
Older Subjects

AbstractCognitive performance slows down with increasing age. This includes cognitive processes that are essential for the performance of a motor act, such as the slowing down in response to an external stimulus. The objective of this study was to identify aging-associated functional changes in the brain networks that are involved in the transformation of external stimuli into motor action. To investigate this topic, we employed dynamic graphs based on phase-locking of Electroencephalography signals recorded from healthy younger and older subjects while performing a simple visually-cued finger-tapping task. The network analysis yielded specific age-related network structures varying in time in the low frequencies (2-7 Hz), which are closely connected to stimulus processing, movement initiation and execution in both age groups. The networks in older subjects, however, contained several additional, particularly interhemispheric, connections and showed an overall increased coupling density. Cluster analyses revealed reduced variability of the subnetworks in older subjects, particularly during movement preparation. In younger subjects, occipital, parietal, sensorimotor and central regions were - temporally arranged in this order - heavily involved in hub nodes. Whereas in older subjects, a hub in frontal regions preceded the noticeably delayed occurrence of sensorimotor hubs, indicating different neural information processing in older subjects.All observed changes in brain network organization, which are based on neural synchronization in the low frequencies, provide a possible neural mechanism underlying previous fMRI data, which report an overactivation, especially in the prefrontal and pre-motor areas, associated with a loss of hemispheric lateralization in older subjects.

Age Differences in Using Precued Information to Preprogram Interception of a Ball

1997 ◽  
Vol 85 (1) ◽  
pp. 123-127 ◽  
Author(s):  
Isabelle Olivier ◽  
Hubert Ripoll ◽  
Michel Audiffren
Keyword(s):  
Age Differences ◽  
Present Experiment ◽  
Critical Period ◽  
Age Groups ◽  
Movement Initiation ◽  
Older Subjects ◽  
Errors Analysis ◽  
Response Errors

The present experiment examined the development of programming interception of a ball's movement across three groups of children ages 6, 8, and 10 years, who were compared with adults. In an interception task we manipulated the subjects' preparation by using Rosenbaum's 1980 precuing procedure. Two levels of precued information were used concerning the effector specified (right or left arm) and the direction of the arm projection (outside or inside). We focused particularly on RT and response errors. Analysis indicated RT decreased across the age groups and errors decreased mainly in the nonprecued condition. A critical period in improvement might be at age 8 as children use precue information to program their movements as efficiently as adults. The duration of effector programming was similar for children and adults but was more precise for the older subjects. For children as well as for adults, the specification of direction occurs after movement initiation and not before.

scholarly journals Age-related changes in spatial and temporal features of resting state fMRI

2017 ◽  
Author(s):  
Shruti G. Vij ◽  
Jason S. Nomi ◽  
Dina R. Dajani ◽  
Lucina Q. Uddin
Keyword(s):  
Resting State ◽  
Large Scale ◽  
Spectral Composition ◽  
Brain Network ◽  
Functional Networks ◽  
Functional Changes ◽  
Age Related ◽  
Temporal Features ◽  
Functional Brain Network ◽  
Age Related Changes

AbstractDevelopment and aging are associated with functional changes in the brain across the lifespan. These changes can be detected in spatial and temporal features of resting state functional MRI (rs-fMRI) data. Independent vector analysis (IVA) is a whole-brain multivariate approach that can be used to comprehensively assess these changes in spatial and temporal features. We present a multi-dimensional approach to assessing age-related changes in spatial and temporal features of statistically independent components identified by IVA in a cross-sectional lifespan sample (ages 6-85 years). We show that while large-scale brain network configurations remain consistent throughout the lifespan, changes continue to occur in both local organization and in the spectral composition of these functional networks. We show that the spatial extent of functional networks decreases with age, but with no significant change in the peak functional loci of these networks. Additionally, we show differential age-related patterns across the frequency spectrum; lower frequency correlations decrease across the lifespan whereas higher-frequency correlations increase. These changes indicate an increasing stability of networks with age. In addition to replicating results from previous studies, the current results uncover new aspects of functional brain network changes across the lifespan that are frequency band-dependent.

Age effects on interrelationships between lung volume and heart rate during standing

1997 ◽  
Vol 273 (5) ◽  
pp. H2128-H2134 ◽  
Author(s):  
Garrett Stanley ◽  
Davide Verotta ◽  
Noah Craft ◽  
Ronald A. Siegel ◽  
Janice B. Schwartz
Keyword(s):  
Heart Rate ◽  
Phase Angle ◽  
Lung Volume ◽  
Repeated Measures ◽  
Transfer Functions ◽  
Age Groups ◽  
Position Effects ◽  
Healthy Humans ◽  
Age Related ◽  
Older Subjects

To determine the effects of aging and posture on the relationship between respiration and heart rate (HR), we collected 5 min of lung volume and R-R interval data from 7 young (27 ± 3 yr, mean ± SD) and 10 old (69 ± 6 yr) healthy humans during spontaneous breathing while they were supine (SU) and standing (ST). Lung volume and HR power spectra and transfer functions between lung volume and HR were estimated. Age and position effects and age-position interactions were determined by analysis of variance for repeated measures. Older subjects had a lower and more variable respiration rate ( P < 0.03, P < 0.04), but both age groups exhibited decreased rate of respiration and increased tidal volume with ST ( P < 0.05, P < 0.005). ST decreased lung volume-to-HR transfer function magnitude in both groups ( P < 0.07). The more marked age-related differences were in phase angle. Both SU and ST phase angles were greater in older subjects ( P < 0.003). ST decreased phase angle in young but increased phase angle in older subjects ( P < 0.001). In conclusion, respiration, and respiration-HR interrelationships are altered by aging, with increased time delays between lung volume and HR and altered relationships with ST.

Age and autonomic effects on interrelationships between lung volume and heart rate

1996 ◽  
Vol 270 (5) ◽  
pp. H1833-H1840 ◽  
Author(s):  
G. Stanley ◽  
D. Verotta ◽  
N. Craft ◽  
R. A. Siegel ◽  
J. B. Schwartz
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Drug Interactions ◽  
Lung Volume ◽  
Repeated Measures ◽  
Transfer Functions ◽  
Age Groups ◽  
Power Spectra ◽  
Age Related ◽  
Older Subjects

To determine effects of aging and autonomic input on interrelationships between respiratory and heart rate variability, we collected 5 min of lung volume of R-R interval data from 7 young [27 +/- 3(SD) yr] and 10 older (69 +/- 6 yr) healthy supine humans before and after double pharmacological autonomic blockade with propranolol (0.2 mg/kg iv) and atropine (0.04 mg/kg iv). Estimates of respiratory and heart rate power spectra and linear transfer functions between the two groups were generated by Fourier analysis. Age, double blockade effects, the age-drug interactions were determined by analysis of variance for repeated measures. Basal R-R intervals were unaffected by age. Double blockade decreased R-R intervals and variability in both age groups (P < 0.0001), but R-R intervals decreased less in older than in young subjects (P < 0.0001). In contrast, basal respiratory intervals and standard deviation were greater in older subjects (P = 0.05) and were unaffected by double blockade in young and older subjects. Lung volume-to-heart rate spectral coherence was highest at frequencies associated with respiration and greater in young than in older subjects (P < 0.07). Double blockade decreased lung volume-to-heart rate variability transfer function magnitude (P < 0.007) and increased phase angle (P < 0.02) without age effects or age-drug interactions. In conclusion, heart rate, respiration, and respiration-heart rate interrelations are altered by aging, and double autonomic pharmacological blockade does not eliminate all age-related differences.

scholarly journals CARDIAC MYBP-C IN C57BL/6 MICE: THE EFFECTS OF AGE

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S904-S904
Author(s):  
Amanda Pinheiro ◽  
Ted G Graber ◽  
LaDora V Thompson
Keyword(s):  
Western Blot ◽  
Cardiac Tissue ◽  
Structural Integrity ◽  
Critical Role ◽  
Age Groups ◽  
Functional Changes ◽  
Age Related ◽  
Significant Difference ◽  
Heart Mass ◽  
Effects Of Aging

Abstract Aging is a known contributor to cardiovascular dysfunction. It is well-established that with age there are functional changes in the heart; yet, the proteins responsible for maintaining sarcomere integrity are not well understood during the aging process. A key protein, cardiac myosin binding protein C (cMyBP-C), contributes to the structural integrity and the regulation of actomyosin interactions. To date, little is known about the effects of aging on cMyBP-C. Therefore, the first step in evaluating this sarcomere protein was to determine the expression of cMyBP-C in cardiac tissue across the lifespan. Using ten C57BL/6 male mice per age group (adult (6-7 months), old (22-25 months), and very old (≥29 months)), body and heart mass were determined. Next a portion of the cardiac tissue was homogenized, and protein concentration was determined (BCA assay). The protein samples were probed for cMyBP-C with MYBPC3 (Abcam, #ab133499) by Western Blot. One-way ANOVA was performed to evaluate differences between groups. Results indicated there was an increase in heart mass with age, but relative to body weight there was no significant difference between the three age groups. Western blot analysis revealed no significant age-related difference in the expression of cMyBP-C. Although there was no change in expression levels, it is not possible to rule out cMyBP-C as a contributor to age-related cardiac dysfunction because phosphorylation is known to play a critical role in the function of cMyBP-C. Thus, further investigation of the phosphorylation status of cMyBP-C is needed and is ongoing.

scholarly journals Impact of interhemispheric inhibition on bimanual movement control in young and old

2022 ◽  
Author(s):  
Takuya Morishita ◽  
Jan E. Timmermann ◽  
Robert Schulz ◽  
Friedhelm C. Hummel
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Age Groups ◽  
Movement Control ◽  
Short Latency ◽  
Bimanual Movement ◽  
Interhemispheric Inhibition ◽  
Functional Changes ◽  
Age Related ◽  
Underlying Mechanisms

AbstractInterhemispheric interactions demonstrate a crucial role for directing bimanual movement control. In humans, a well-established paired-pulse transcranial magnetic stimulation paradigm enables to assess these interactions by means of interhemispheric inhibition (IHI). Previous studies have examined changes in IHI from the active to the resting primary motor cortex during unilateral muscle contractions; however, behavioral relevance of such changes is still inconclusive. In the present study, we evaluated two bimanual tasks, i.e., mirror activity and bimanual anti-phase tapping, to examine behavioral relevance of IHI for bimanual movement control within this behavioral framework. Two age groups (young and older) were evaluated as bimanual movement control demonstrates evident behavioral decline in older adults. Two types of IHI with differential underlying mechanisms were measured; IHI was tested at rest and during a motor task from the active to the resting primary motor cortex. Results demonstrate an association between behavior and short-latency IHI in the young group: larger short-latency IHI correlated with better bimanual movement control (i.e., less mirror activity and better bimanual anti-phase tapping). These results support the view that short-latency IHI represents a neurophysiological marker for the ability to suppress activity of the contralateral side, likely contributing to efficient bimanual movement control. This association was not observed in the older group, suggesting age-related functional changes of IHI. To determine underlying mechanisms of impaired bimanual movement control due to neurological disorders, it is crucial to have an in-depth understanding of age-related mechanisms to disentangle disorder-related mechanisms of impaired bimanual movement control from age-related ones.

Age-related changes in the twitch contractile properties of human thenar motor units

1997 ◽  
Vol 82 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Timothy J. Doherty ◽  
William F. Brown
Keyword(s):  
Relaxation Times ◽  
Age Groups ◽  
Motor Units ◽  
Contractile Properties ◽  
Electrophysiological Properties ◽  
Age Related ◽  
Wide Range ◽  
Older Subjects ◽  
Effects Of Aging ◽  
Age Related Changes

Doherty, Timothy J., and William F. Brown. Age-related changes in the twitch contractile properties of human thenar motor units. J. Appl. Physiol. 82(1): 93–101, 1997.—The purpose of this study was to examine the effects of aging on the contractile and electrophysiological properties of human thenar motor units (MUs). Percutaneous electrical stimulation of single motor axons within the median nerve was used to isolate and examine the twitch tensions, contractile speeds, and surface-detected MU action potential (S-MUAP) sizes of 48 thenar MUs in 17 younger subjects (25–53 yr) and 44 thenar MUs in 9 older subjects (64–77 yr). A wide range of twitch tensions, contractile speeds, and S-MUAP sizes was observed in both age groups. However, older subjects had significantly larger MU twitch tensions and slower MU twitch contraction and half-relaxation times. These changes were accompanied by increased S-MUAP sizes. These findings suggest that the human thenar MU pool undergoes significant age-related increase in MU size and slowing of contractile speed. Such adaptation may help to overcome previously reported age-related losses of thenar MUs.

Differences in Trunk Kinematics and Ground Reaction Forces Between Older and Younger Adults during Lifting

2005 ◽  
Vol 49 (2) ◽  
pp. 177-181
Author(s):  
Gwanseob Shin ◽  
Mack L. Nance ◽  
Gary A. Mirka
Keyword(s):  
Center Of Pressure ◽  
Age Groups ◽  
Force Plate ◽  
Ground Reaction Forces ◽  
Younger Adults ◽  
Age Related ◽  
Reaction Forces ◽  
Older Subjects ◽  
Trunk Kinematics ◽  
Two Age Groups

Trunk kinematics, ground reaction forces, and the motion of the center of pressure (COP) of older and younger subjects were compared in lifting to study age-related differences between the two age groups. Ten older (55 ∼ 63 years old) and ten younger (19 ∼ 29 years old) adults performed lifting tasks under six different conditions; three destination heights and two asymmetry angles of origin. Subjects' trunk kinematics, ground reaction forces and COP motions were measured by the Lumbar Motion Monitor (LMM) and a force plate. Older subjects showed significantly less trunk kinematics, peak ground reaction forces, and COP motions than younger subjects, indicating older subjects chose more stable lifting strategy and it might compensate for the decreased ability of postural control over age. Less ground reaction forces and motion of COP suggested that risks of falls and slips of older subjects were less than younger subjects.

scholarly journals THE MORPHOLOGY OF THE PINEAL GLAND OF THE INDIGENOUS POPULATION OF THE YAKUTIA IN THE AGE ASPECT

2019 ◽  
Vol 27 (3) ◽  
pp. 51-55
Author(s):  
A. Y. Sleptsov ◽  
D. K. Garmaeva ◽  
D. S. Belolyubskaya
Keyword(s):  
Pineal Gland ◽  
Functional Activity ◽  
Indigenous Population ◽  
Age Groups ◽  
Sharp Decrease ◽  
Age Group ◽  
Dark Cell ◽  
Functional Changes ◽  
Age Related ◽  
Younger Age

The pineal gland is a functionally light-dependent organ located in different conditions depending on living in different latitudes. Insufficient data on the morphological and functional state of the human pineal gland under various living conditions constitute a significant gap in the study of the pineal gland. A morphological study of the epiphysis of the indigenous population of different age groups was carried out, obtained during of autopsies on in the pathology department of the National Center of Medicine of Yakutsk (Republic of Sakha). The methods of morphometric analysis with the calculation of indicators of the area of pinealocyte karyons and the quantitative assessment of pineal gland parenchyma cells were used. The data obtained show age-related changes in morphological and functional activity, including changes in the size of light and dark cell karyons in the oldest age group. The largest deviations were observed among dark cells, probably indicating their transition and replenishment of active secreting pinealocytes against the background of a general decrease in the number of cells associated with fibrosis and organ calcification. In the group of 6069 years old, there is an increase in the number of gliocytes, significant compared with the younger age group. In the group of the oldest age, a sharp decrease in their number is noted. Age-related morphological and functional changes in the pineal gland in the indigenous population of Yakutia are most evident at the age of 60-69 and include signs of a decrease in the functional activity of pinealocytes, progressive calcification of the pineal gland, accumulation of neural pigment and proliferation of connective tissue, with the formation of a stromal type of structure.

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