Oscillatory Corticospinal Activity during Static Contraction of Ankle Muscles Is Reduced in Healthy Old versus Young Adults

Aging is accompanied by impaired motor function, but age-related changes in neural networks responsible for generating movement are not well understood. We aimed to investigate the functional oscillatory coupling between activity in the sensorimotor cortex and ankle muscles during static contraction. Fifteen young (20–26 yr) and fifteen older (65–73 yr) subjects were instructed to match a target force by performing static ankle dorsi- or plantar flexion, while electroencephalographic (EEG) activity was recorded from the cortex and electromyographic (EMG) activity was recorded from dorsi- (proximal and distal anterior tibia) and plantar (soleus and medial gastrocnemius) flexor muscles. EEG-EMG and EMG-EMG beta band (15–35 Hz) coherence was analyzed as an index of corticospinal activity. Our results demonstrated that beta cortico-, intra-, and intermuscular coherence was reduced in old versus young subjects during static contractions. Old subjects demonstrated significantly greater error than young subjects while matching target forces, but force precision was not related to beta coherence. We interpret this as an age-related decrease in effective oscillatory corticospinal activity during steady-state motor output. Additionally, our data indicate a potential effect of alpha coherence and tremor on performance. These results may be instrumental in developing new interventions to strengthen sensorimotor control in elderly subjects.

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Specific modulation of corticomuscular coherence during submaximal voluntary isometric, shortening and lengthening contractions

Scientific Reports ◽

10.1038/s41598-021-85851-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Dorian Glories ◽

Mathias Soulhol ◽

David Amarantini ◽

Julien Duclay

Keyword(s):

H Reflex ◽

Medial Gastrocnemius ◽

Emg Activity ◽

Beta Band ◽

Lengthening Contractions ◽

Time Frequency ◽

Corticomuscular Coherence ◽

Emg Signal ◽

Voluntary Contractions ◽

Spinal Excitability

AbstractDuring voluntary contractions, corticomuscular coherence (CMC) is thought to reflect a mutual interaction between cortical and muscle oscillatory activities, respectively measured by electroencephalography (EEG) and electromyography (EMG). However, it remains unclear whether CMC modulation would depend on the contribution of neural mechanisms acting at the spinal level. To this purpose, modulations of CMC were compared during submaximal isometric, shortening and lengthening contractions of the soleus (SOL) and the medial gastrocnemius (MG) with a concurrent analysis of changes in spinal excitability that may be reduced during lengthening contractions. Submaximal contractions intensity was set at 50% of the maximal SOL EMG activity. CMC was computed in the time–frequency domain between the Cz EEG electrode signal and the unrectified SOL or MG EMG signal. Spinal excitability was quantified through normalized Hoffmann (H) reflex amplitude. The results indicate that beta-band CMC and normalized H-reflex were significantly lower in SOL during lengthening compared with isometric contractions, but were similar in MG for all three muscle contraction types. Collectively, these results highlight an effect of contraction type on beta-band CMC, although it may differ between agonist synergist muscles. These novel findings also provide new evidence that beta-band CMC modulation may involve spinal regulatory mechanisms.

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Extra Virgin Olive Oil Prevents the Age-Related Shifts of the Distribution of HDL Subclasses and Improves Their Functionality

Nutrients ◽

10.3390/nu13072235 ◽

2021 ◽

Vol 13 (7) ◽

pp. 2235

Author(s):

Alyann Otrante ◽

Amal Trigui ◽

Roua Walha ◽

Hicham Berrougui ◽

Tamas Fulop ◽

...

Keyword(s):

Olive Oil ◽

Virgin Olive Oil ◽

Density Lipoprotein ◽

Extra Virgin Olive Oil ◽

The Elderly ◽

High Density ◽

Lipoprotein Cholesterol ◽

Elderly Subjects ◽

Age Related ◽

Young Subjects

High-density lipoproteins (HDL) maintain cholesterol homeostasis through the role they play in regulating reverse cholesterol transport (RCT), a process by which excess cholesterol is transported back to the liver for elimination. However, RCT can be altered in the presence of cardiovascular risk factors, such as aging, which contributes to the increase in the incidence of cardiovascular diseases (CVD). The present study was aimed at investigating the effect of extra virgin olive oil (EVOO) intake on the cholesterol efflux capacity (CEC) of HDL, and to elucidate on the mechanisms by which EVOO intake improves the anti-atherogenic activity of HDL. A total of 84 healthy women and men were enrolled and were distributed, according to age, into two groups: 27 young (31.81 ± 6.79 years) and 57 elderly (70.72 ± 5.6 years) subjects. The subjects in both groups were given 25 mL/d of extra virgin olive oil (EVOO) for 12 weeks. CEC was measured using J774 macrophages radiolabeled with tritiated cholesterol ((3H) cholesterol). HDL subclass distributions were analyzed using the Quantimetrix Lipoprint® system. The HDL from the elderly subjects exhibited a lower level of CEC, at 11.12% (p < 0.0001), than the HDL from the young subjects. The CEC of the elderly subjects returned to normal levels following 12 weeks of EVOO intake. An analysis of the distribution of HDL subclasses showed that HDL from the elderly subjects were composed of lower levels of large HDL (L-HDL) (p < 0.03) and higher levels of small HDL (S-HDL) (p < 0.002) compared to HDL from the young subjects. A multiple linear regression analysis revealed a positive correlation between CEC and L-HDL levels (r = 0.35 and p < 0.001) as well as an inverse correlation between CEC and S-HDL levels (r = −0.27 and p < 0.01). This correlation remained significant even when several variables, including age, sex, and BMI as well as low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and glucose levels (β = 0.28, p < 0.002, and β = 0.24, p = 0.01) were accounted for. Consuming EVOO for 12 weeks modulated the age-related difference in the distribution of HDL subclasses by reducing the level of S-HDL and increasing the level of intermediate-HDL/large-HDL (I-HDL/L-HDL) in the elderly subjects. The age-related alteration of the CEC of HDL was due, in part, to an alteration in the distribution of HDL subclasses. A diet enriched in EVOO improved the functionality of HDL through an increase in I-HDL/L-HDL and a decrease in S-HDL.

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Decreased Neutrophil Cyclic AMP Response to Isoprenaline Stimulation in the Elderly

Clinical Science ◽

10.1042/cs0650155 ◽

1983 ◽

Vol 65 (2) ◽

pp. 155-157 ◽

Cited By ~ 13

Author(s):

T. G. Cotter ◽

K. O'Malley

Keyword(s):

Monoclonal Antibodies ◽

Cyclic Amp ◽

The Elderly ◽

Population Heterogeneity ◽

Elderly Subjects ◽

Age Related ◽

Significant Difference ◽

Young Subjects ◽

Drug Free

1. Neutrophils from drug-free elderly subjects produced approximately 50% less cyclic AMP in response to isoprenaline than did neutrophils from young subjects. A significant difference in basal cyclic AMP levels was also evident (elderly 2.8 ± 0.37; young 4.9 ± 0.36 pmol of cAMP/107 cells; P < 0.05). 2. With a range of anti-neutrophil monoclonal antibodies no evidence of age-related neutrophil population heterogeneity was found. 3. These findings indicate that the age-related decline in β-adrenoceptor responsiveness is not due to changes in the neutrophil population. 4. The present results support the hypothesis that there is a generalized decline in β-adrenoceptor-mediated responsiveness in the elderly.

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Age-related changes in multifinger synergies in accurate moment of force production tasks

Journal of Applied Physiology ◽

10.1152/japplphysiol.00966.2006 ◽

2007 ◽

Vol 102 (4) ◽

pp. 1490-1501 ◽

Cited By ~ 57

Author(s):

Halla Olafsdottir ◽

Wei Zhang ◽

Vladimir M. Zatsiorsky ◽

Mark L. Latash

Keyword(s):

Hand Function ◽

The Elderly ◽

Time Profile ◽

Uncontrolled Manifold ◽

Elderly Subjects ◽

Total Force ◽

Dominant Hand ◽

Total Moment ◽

Age Related ◽

Young Subjects

The purpose of this investigation was to document and quantify age-related differences in the coordination of fingers during a task that required production of an accurate time profile of the total moment of force by the four fingers of a hand. We hypothesized that elderly subjects would show a decreased ability to stabilize a time profile of the total moment of force, leading to larger indexes of moment variability compared with young subjects. The subjects followed a trapezoidal template on a computer screen by producing a time profile of the total moment of force while pressing down on force sensors with the four fingers of the right (dominant) hand. To quantify synergies, we used the framework of the uncontrolled manifold hypothesis. The elderly subjects produced larger total force, larger variance of both total force and total moment of force, and larger involvement of fingers that produced moment of force against the required moment direction (antagonist moment). This was particularly prominent during supination efforts. Young subjects showed covariation of commands to fingers across trials that stabilized the moment of total force (moment-stabilizing synergy), while elderly subjects failed to do so. Both subject groups showed similar indexes of covariation of commands to the fingers that stabilized the time profile of the total force. The lack of moment-stabilizing synergies may be causally related to the documented impairment of hand function with age.

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Maximum Voluntary Activation in Nonfatigued and Fatigued Muscle of Young and Elderly Individuals

Physical Therapy ◽

10.1093/ptj/81.5.1102 ◽

2001 ◽

Vol 81 (5) ◽

pp. 1102-1109 ◽

Cited By ~ 127

Author(s):

Scott K Stackhouse ◽

Jennifer E Stevens ◽

Samuel CK Lee ◽

Karen M Pearce ◽

Lynn Snyder-Mackler ◽

...

Keyword(s):

Maximum Voluntary Contraction ◽

Quadriceps Femoris ◽

Voluntary Contraction ◽

Voluntary Activation ◽

Elderly Subjects ◽

Central Activation ◽

Quadriceps Femoris Muscle ◽

Age Related ◽

Young Subjects ◽

Femoris Muscle

Abstract Background and Purpose. Researchers studying central activation of muscles in elderly subjects (≥65 years of age) have investigated activation in only the nonfatigued state. This study examined the ability of young and elderly people to activate their quadriceps femoris muscles voluntarily under both fatigued and nonfatigued conditions to determine the effect of central activation failure on age-related loss of force. Subjects and Methods. Twenty young subjects (11 men, 9 women; mean age=22.67 years, SD=4.14, range=18–32 years) and 17 elderly subjects (8 men, 9 women; mean age=71.5 years, SD=5.85, range=65–84 years) participated in this study. Subjects were seated on a dynamometer and stabilized. Central activation was quantified, based on the change in force produced by a 100-Hz, 12-pulse electrical train that was delivered during a 3- to 5-second isometric maximum voluntary contraction (MVC) of the quadriceps femoris muscle. Next, subjects performed 25 MVCs (a 5-second contraction with 2 seconds of rest) to fatigue the muscle. During the last MVC, central activation was measured again. Results. In the nonfatigued state, elderly subjects had lower central activation than younger subjects. In the fatigued state, this difference became larger. Discussion and Conclusion. Central activation of the quadriceps femoris muscle in elderly subjects was reduced in both the fatigued and nonfatigued states when compared with young subjects. Some part of age-related weakness, therefore, may be attributed to failure of central activation in both the fatigued and nonfatigued states.

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Effect of ‘Autonomic Blockade’ on Cardiac β-Adrenergic Chronotropic Responsiveness in Healthy Young, Healthy Elderly and Endurance-Trained Elderly Subjects

Clinical Science ◽

10.1042/cs0870297 ◽

1994 ◽

Vol 87 (3) ◽

pp. 297-302 ◽

Cited By ~ 15

Author(s):

G. A. Ford ◽

O. F. W. James

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Geometric Mean ◽

Cardiovascular Responses ◽

The Elderly ◽

Elderly Subjects ◽

Healthy Elderly ◽

Age Related ◽

Autonomic Blockade ◽

Young Subjects

1. Cardiac chronotropic responses to isoprenaline are reduced with ageing in man. It is unclear whether this is due to reduced cardiac β-adrenergic sensitivity or to age-associated differences in reflex cardiovascular responses to the vasodilatory effects of isoprenaline. Age-associated changes in physical activity are also reported to influence β-adrenergic sensitivity. 2. The aim of the present study was to determine the contribution of alterations in reflex changes in parasympathetic and sympathetic influences and physical fitness to the age-associated reduction in cardiac chronotropic responses to β-adrenergic agonists. 3. The effect of ‘autonomic blockade’ with atropine (40 μg/kg intravenously) and clonidine (4 μg/kg intravenously) on blood pressure, heart rate and chronotropic responses to intravenous bolus isoprenaline doses was determined in eight healthy young (mean age 21 years), nine healthy elderly (72 years) and 10 endurance-trained elderly (69 years) subjects. 4. Elderly subjects had a reduced increase in heart rate after atropine (young, 49 ± 9 beats/min; elderly, 36 ± 5 beats/min; endurance-trained elderly, 34 ± 12 beats/min; P < 0.01) and did not demonstrate the transient increase in systolic blood pressure after clonidine observed in young subjects (young, 11 ± 10 mmHg; elderly, −12 ± 16 mmHg; endurance-trained elderly, −18 ± 11 mmHg; P < 0.01). 5. Cardiac chronotropic sensitivity to isoprenaline after ‘autonomic blockade’ increased in the young but decreased in the elderly subjects. The isoprenaline dose that increased heart rate by 25 beats/min before and after autonomic blockade' was: young, before 1.6 μg, after 2.8 μg, P < 0.01 (geometric mean, paired test); elderly, before 6.9 μg, after 3.6 μg, P < 0.05; endurance-trained elderly, before 5.9 μg, after 4.0 μg, P < 0.05. Cardiac chronotropic sensitivity to isoprenaline was significantly reduced in elderly compared with young subjects before (P < 0.01) but was similar after (P = 0.09) ‘autonomic blockade’. Chronotropic sensitivity did not differ between healthy and endurance-trained elderly subjects before or after ‘autonomic blockade’. 6. The age-associated reduction in cardiac chronotropic responses to bolus isoprenaline is primarily due to an age-related reduction in the influence of reflex cardiovascular responses on heart rate and not to an age-related reduction in cardiac β-adrenergic sensitivity. Endurance training is not associated with altered β-adrenergic chronotropic sensitivity in the elderly. The transient pressor response to intravenously administered clonidine may be lost in ageing man.

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Muscle metabolism in older subjects using 31P magnetic resonance spectroscopy

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y91-084 ◽

1991 ◽

Vol 69 (5) ◽

pp. 576-580 ◽

Cited By ~ 47

Author(s):

Kevin K. McCully ◽

Mary Ann Forciea ◽

Laurita M. Hack ◽

Eileen Donlon ◽

Roger W. Wheatley ◽

...

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Spectroscopy ◽

Time Constant ◽

Plantar Flexion ◽

Muscle Metabolism ◽

The Elderly ◽

Elderly Subjects ◽

Resonance Spectroscopy ◽

Medical Problems ◽

Age Related

We used phosphorus magnetic resonance spectroscopy to study the calf muscles of elderly normal (mean ± SD) (80.0 ± 5.12 years), elderly impaired (80.7 ± 0.58 years), old normal (66.8 ± 1.92 years), and young normal people (24.6 ± 4.72 years). Relative levels of inorganic phosphate (Pi), phosphocreatine (PCr), and adenosine triphosphate were measured with a 1.9-tesla, 30-cm bore magnet at rest and following plantra flexon exercise. No differences were found at rest or during recovery from exercise in the elderly normal subjects with respect to gender or the presence of stable medical problems treated with medication. At rest there was an age-related decrease in the ratio of PCr/Pi. After exercise, the time constant of PCr recovery increased with age. A mild 7-week exercise regimen consisting of plantar flexion had no effect on time constant of PCr recovery in the elderly subjects. Four elderly impaired subjects had lower PCr/Pi ratios at rest and slower time constant of PCr recovery after exercise than normal elderly subjects. We conclude that gender and the presence of stable medical problems had no effect on muscle metabolism in the elderly and that the elderly recovered slower than young controls. This slower recovery was not corrected with a mild exercise program.Key words: human muscle, aging, exercise, nuclear magnetic resonance, gastrocnemius.

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Effects of Aging on Motor-Unit Control Properties

Journal of Neurophysiology ◽

10.1152/jn.1999.82.5.2081 ◽

1999 ◽

Vol 82 (5) ◽

pp. 2081-2091 ◽

Cited By ~ 154

Author(s):

Zeynep Erim ◽

M. Faisal Beg ◽

David T. Burke ◽

Carlo J. de Luca

Keyword(s):

Firing Rate ◽

Motor Unit ◽

Motor Units ◽

Elderly Subjects ◽

Compensatory Mechanism ◽

Type I ◽

Firing Behavior ◽

Firing Rates ◽

Age Related ◽

Young Subjects

It was hypothesized that the age-related alterations in the morphological properties of a motor unit would be accompanied by modifications in the control aspects of the motor unit, as either an adaptive or compensatory mechanism to preserve smooth force production. In specific, the objective of the study was to investigate the age-related alterations in the concurrent firing behavior of multiple motor units in the first dorsal interosseous (FDI) muscle in isometric contractions at 20 and 50% of the subject's voluntary contraction level. Analysis of the data collected from 10 young (24–37 yr of age) and 10 elderly (65–88 yr of age) subjects led to three novel observations regarding the firing behavior of aged motor units. 1) Among elderly subjects, there is a decrease in the common fluctuations that are observed among the firing rates of motor units in the young. 2) The relationship observed between the firing rate and recruitment threshold of young subjects is disturbed in the elderly. Although in young subjects, at any point in a given submaximal contraction, earlier recruited motor units have higher firing rates than later-recruited units; in aged subjects this dependency of firing rate on recruitment rank is compromised. 3) The progressive decrease observed in the firing rates of concurrently active motor units in constant-force contractions in the young is not seen in the aged. In addition to these original findings, this study provided support for earlier reports of 1) decreased average firing rates probably reflecting the slowing of the muscle, 2) a shift in recruitment thresholds toward lower force levels in line with the shift toward type I fibers, and 3) multiphasic action potential shapes indicative of the reinnervation process that takes place during aging. Taken as a whole, these findings indicate significant age-related modifications in the control properties of human motor units.

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Age-Related Changes in Spontaneous Oscillations Assessed by Wavelet Transform of Cerebral Oxygenation and Arterial Blood Pressure Signals

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2013.4 ◽

2013 ◽

Vol 33 (5) ◽

pp. 692-699 ◽

Cited By ~ 35

Author(s):

Zengyong Li ◽

Ming Zhang ◽

Qing Xin ◽

Site Luo ◽

Ruofei Cui ◽

...

Keyword(s):

Blood Pressure ◽

Wavelet Transform ◽

Arterial Blood Pressure ◽

Cerebral Oxygenation ◽

Oxygenation Index ◽

Elderly Subjects ◽

Arterial Blood ◽

Age Related ◽

Spontaneous Oscillations ◽

Young Subjects

The study aims to assess the spontaneous oscillations in elderly subjects based on the wavelet transform of cerebral oxygenation (CO) and arterial blood pressure (ABP) signals. Continuous recordings of near-infrared spectroscopy (NIRS) and ABP signals were obtained from simultaneous measurements in 20 young subjects (age: 27.3 ± 7.1 years) and 15 elderly subjects (age: 70.8 ± 5.1 years) at rest. Using spectral analysis based on wavelet transform, five frequency intervals were identified (I, 0.005 to 0.02 Hz; II, 0.02 to 0.06 Hz; III, 0.06 to 0.15 Hz; IV, 0.15 to 0.40 Hz; and V, 0.40 to 2.0 Hz). The average amplitudes of the Δ[HbO2] and tissue oxygenation index in intervals I to V and the relative amplitudes in intervals IV and V were significantly lower in elderly subjects than in young subjects ( P < 0.05). In addition, the relative amplitudes of the ABP in interval I were significantly lower in elderly subjects than in young subjects ( P = 0.016). The present findings suggest the presence of a cerebrovascular degenerative process caused by aging. Spontaneous oscillations in the CO could be used as an indicator of cerebrovascular changes and could be used to identify the risk for cerebrovascular degenerative processes.

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Cortical thickness of the tibial diaphysis reveals age- and sex-related characteristics between non-obese healthy young and elderly subjects depending on the tibial regions

Journal of Experimental Orthopaedics ◽

10.1186/s40634-020-00297-9 ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Keisuke Maeda ◽

Tomoharu Mochizuki ◽

Koichi Kobayashi ◽

Osamu Tanifuji ◽

Keiichiro Someya ◽

...

Keyword(s):

Cortical Thickness ◽

Structural Characteristics ◽

Reference Points ◽

Elderly Subjects ◽

Tibial Diaphysis ◽

Related Difference ◽

Age Related ◽

Young Subjects ◽

Young And Elderly Subjects ◽

Age And Sex

Abstract Purpose This study aimed to evaluate the age- and sex-related characteristics in cortical thickness of the tibial diaphysis between non-obese healthy young and elderly subjects as reference data. Methods The study investigated 31 young subjects (12 men and 19 women; mean age, 25 ± 8 years) and 54 elderly subjects (29 men and 25 women; mean age, 70 ± 6 years). Three-dimensional estimated cortical thickness of the tibial diaphysis was automatically calculated for 5000–9000 measurement points using the high-resolution cortical thickness measurement from clinical computed tomography data. In 12 assessment regions created by combining three heights (proximal, central, and distal diaphysis) and four areas of the axial plane at 90° (medial, anterior, lateral, and posterior areas) in the tibial coordinate system, the standardized thickness was assessed using the tibial length. Results As structural characteristics, there were no differences in the medial and lateral thicknesses, while the anterior thickness was greater than the posterior thickness in all groups. The sex-related difference was not shown. As an age-related difference, elderly subjects showed greater or lesser cortical thickness than the young subjects, depending on the regions of the tibia. Conclusions Cortical thickness was different depending on sex, age, and regions in the tibia. The results of this study are of clinical relevance as reference points to clarify the causes of various pathological conditions for diseases. Level of evidence Level 3.

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