scholarly journals Humans exploit robust locomotion by improving the stability of control signals

2019 ◽  
Author(s):  
Alessandro Santuz ◽  
Leon Brüll ◽  
Antonis Ekizos ◽  
Arno Schroll ◽  
Nils Eckardt ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Older Age ◽  
Muscle Synergies ◽  
Rough Terrain ◽  
Control Signals ◽  
Age Related ◽  
The Central Nervous System ◽  
The Stability ◽  
Over Time

AbstractIs the control of movement less stable when we walk or run in challenging settings? One might intuitively answer affirmatively, given that adding constraints to locomotion (e.g. rough terrain, age-related impairments, etc.) imply less stable movements. We investigated how young and old humans synergistically activate muscles during locomotion, when different perturbation levels are introduced. Of these control signals, called muscle synergies, we then analyzed the stability over time. Surprisingly, we found that perturbations and older age force the central nervous system to produce more stable signals. These outcomes show that robust locomotion in challenging settings is achieved by increasing the stability of control signals, whereas easier tasks allow for more unstable control.

Effect of amobarbital on the course of human dark adaptation

1961 ◽  
Vol 16 (2) ◽  
pp. 361-366 ◽  
Author(s):  
G. W. Granger
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Oral Administration ◽  
White Light ◽  
Dark Adaptation ◽  
Light Adaptation ◽  
Visual Adaptation ◽  
Test Field ◽  
The Central Nervous System ◽  
The Stability

Following light adaptation to a luminance of 120 mL for 5 minutes, absolute thresholds for a centrally fixated, 7-degree test field in 'white' light were measured during the course of 30 minutes' dark adaptation. Viewing was monocular and the measuring light was exposed in 0.018-second flashes. The resulting curves, defining the relation between log threshold luminance and time in the dark, displayed the typical features of 'rod' dark adaptation and were found to be highly reproducible in three experienced observers. Neither the shape of the curves nor their position along the log luminance axis was affected by the oral administration of a sedative dose (0.30 gm/70 kg) of amobarbital. It was concluded that the results supported the views of Hecht and other photochemical theorists concerning the stability of human dark adaptation and its resistance to fluctuations in the state of the central nervous system, but were not necessarily incompatible, as was sometimes supposed, with the hypothesis of a neural component in visual adaptation. Submitted on May 23, 1960

Counteracting Psychological Fatigue Effects by Stimulus Change

1974 ◽  
Vol 18 (2) ◽  
pp. 219-224 ◽  
Author(s):  
Corwin A. Bennett ◽  
Frederick S. Marcellus ◽  
James F. Reynolds
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Stimulus Change ◽  
Low Energy ◽  
The Other ◽  
Performance Loss ◽  
Rest Periods ◽  
Performance Effects ◽  
The Central Nervous System ◽  
Over Time

Psychological fatigue effects, while they presumably result from some changes in the central nervous system, may best be defined today as performance loss over time when respiratory, circulatory and musculature disfunctioning are not involved. Most research recently on psychological fatigue has been under the rubric of “vigilence” where the worker is generally passive. Much procedural work (repetitive with low energy expenditure) involves activity which over a period of time may have fatigue performance effects as well as being boring. Two experiments were carried out on thirty and twenty subjects performing arithmetic for three hours. In one study three groups of matched subjects had no rest periods, passive rest or active rest periods. Active rest was superior to the other conditions. In the other study no rest was used, but one of two groups of matched subjects was rotated to a non-arithmetic clerical task briefly. This change-of-task produced reduced fatigue effects.

scholarly journals Antioxidant Defense Mechanisms in Erythrocytes and in the Central Nervous System

Antioxidants ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 46 ◽  
Author(s):  
Rafael Franco ◽  
Gemma Navarro ◽  
Eva Martínez-Pinilla
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Defense Mechanisms ◽  
Antioxidant Defense ◽  
Circulatory System ◽  
Reducing Power ◽  
Antioxidant Defense System ◽  
Age Related ◽  
The Central Nervous System ◽  
High Level

Differential antioxidant action is found upon comparison of organ/tissue systems in the human body. In erythrocytes (red blood cells), which transport oxygen and carbon dioxide through the circulatory system, the most important issue is to keep hemoglobin in a functional state that requires maintaining the haem group in ferrous (Fe2+) state. Conversion of oxidized Fe3+ back into Fe2+ in hemoglobin needs a special mechanism involving a tripeptide glutathione, glucose-6-phosphate dehydrogenase, and glucose and NADPH as suppliers of reducing power. Fava beans are probably a good resource to make the detox innate system more robust as the pro-oxidant molecules in this food likely induce the upregulation of members of such mechanisms. The central nervous system consumes more oxygen than the majority of human tissues, i.e., 20% of the body’s total oxygen consumption and, therefore, it is exposed to a high level of oxidative stress. This fact, together with the progressive age-related decline in the efficiency of the antioxidant defense system, leads to neuronal death and disease. The innate mechanism operating in the central nervous system is not well known and seems different to that of the erythrocytes. The strategies of antioxidant intervention in brain will be reviewed here.

Insulin secretion: mechanism of the stimulation by glucose

1975 ◽  
Vol 8 (1) ◽  
pp. 1-41 ◽  
Author(s):  
Erol Cerasi
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Insulin Secretion ◽  
Blood Glucose ◽  
Food Intake ◽  
Blood Glucose Level ◽  
Glucose Level ◽  
Glucose Concentration ◽  
The Central Nervous System ◽  
The Stability

Glucose is one of the substrates that is controlled with the most efficient hormonal mechanisms in higher organisms. The presence of tissues such as the central nervous system which, under normal conditions, depend solely on glucose as substrate, and the sporadic type of food intake with periods of fasting of various lengths in the mammalians necessitate that the distribution of energy-rich substrates among various tissues be continuously adjusted by changes in the secretion of a number of hormones. The efficiency of this system is evidenced by the stability of the blood glucose level in man, in whom after a carbohydrate-rich meal more than 70% of the glucose that has been ingested will be retained in the liver during a single passage of portal blood, resulting in only small changes of the glucose concentration in peripheral blood. Likewise, periods of fasting up to24–36 h are followed by modest to minimal reductions of the blood glucose level, the liver now supplying the circulation with the hexose.

Age-related Degradation in the Central Nervous System: Assessment with Diffusion-Tensor Imaging and Quantitative Fiber Tracking

Radiology ◽  
2008 ◽  
Vol 247 (1) ◽  
pp. 179-188 ◽  
Author(s):  
Andreas Stadlbauer ◽  
Erich Salomonowitz ◽  
Guido Strunk ◽  
Thilo Hammen ◽  
Oliver Ganslandt
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Diffusion Tensor Imaging ◽  
Diffusion Tensor ◽  
Fiber Tracking ◽  
Age Related ◽  
The Central Nervous System ◽  
System Assessment

scholarly journals An Immunohistochemical and Ultrastructural Study on Age-Related Astrocytic Gliosis in the Central Nervous System of Dogs.

1992 ◽  
Vol 54 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Akinori SHIMADA ◽  
Mitsuru KUWAMURA ◽  
Tsuyoshi AWAKURA ◽  
Takashi UMEMURA ◽  
Chitoshi ITAKURA
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Ultrastructural Study ◽  
Age Related ◽  
The Central Nervous System

scholarly journals Homocysteine and Age-Related Central Nervous System Diseases: Role of Inflammation

2021 ◽  
Vol 22 (12) ◽  
pp. 6259
Author(s):  
Amany Tawfik ◽  
Nehal M. Elsherbiny ◽  
Yusra Zaidi ◽  
Pragya Rajpurohit
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Barrier Function ◽  
Underlying Mechanism ◽  
Age Related Macular Degeneration ◽  
Barrier Dysfunction ◽  
Age Related ◽  
The Central Nervous System ◽  
Underlying Mechanisms

Hyperhomocysteinemia (HHcy) is remarkably common among the aging population. The relation between HHcy and the development of neurodegenerative diseases, such as Alzheimer’s disease (AD) and eye diseases, and age-related macular degeneration (AMD) and diabetic retinopathy (DR) in elderly people, has been established. Disruption of the blood barrier function of the brain and retina is one of the most important underlying mechanisms associated with HHcy-induced neurodegenerative and retinal disorders. Impairment of the barrier function triggers inflammatory events that worsen disease pathology. Studies have shown that AD patients also suffer from visual impairments. As an extension of the central nervous system, the retina has been suggested as a prominent site of AD pathology. This review highlights inflammation as a possible underlying mechanism of HHcy-induced barrier dysfunction and neurovascular injury in aging diseases accompanied by HHcy, focusing on AD.

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