scholarly journals Age-related reweighting of visual and vestibular cues for vertical perception

2019 ◽  
Vol 121 (4) ◽  
pp. 1279-1288 ◽  
Author(s):  
Bart B. G. T. Alberts ◽  
Luc P. J. Selen ◽  
W. Pieter Medendorp
Keyword(s):  
Spatial Orientation ◽  
Contextual Information ◽  
Sensory Information ◽  
The Body ◽  
Individual Subject ◽  
Noise Characteristics ◽  
Age Related ◽  
Vestibular Cues ◽  
Age Dependent ◽  
Visual Frame

As we age, the acuity of our sensory organs declines, which may affect our lifestyle. Sensory deterioration in the vestibular system is typically bilateral and gradual, and could lead to problems with balance and spatial orientation. To compensate for the sensory deterioration, it has been suggested that the brain reweights the sensory information sources according to their relative noise characteristics. For rehabilitation and training programs, it is important to understand the consequences of this reweighting, preferably at the individual subject level. We psychometrically examined the age-dependent reweighting of visual and vestibular cues used in spatial orientation in a group of 32 subjects (age range: 19–76 yr). We asked subjects to indicate the orientation of a line (clockwise or counterclockwise relative to the gravitational vertical) presented within an oriented square visual frame when seated upright or with their head tilted 30° relative to the body. Results show that subjects’ vertical perception is biased by the orientation of the visual frame. Both the magnitude of this bias and response variability become larger with increasing age. Deducing the underlying sensory noise characteristics, using Bayesian inference, suggests an age-dependent reweighting of sensory information, with an increasing weight of the visual contextual information. Further scrutiny of the model suggests that this shift in sensory weights is the result of an increase in the noise of the vestibular signal. Our approach quantifies how noise properties of visual and vestibular systems change over the life span, which helps to understand the aging process at the neurocomputational level. NEW & NOTEWORTHY Perception of visual vertical involves a weighted fusion of visual and vestibular tilt cues. Using a Bayesian approach and experimental psychophysics, we quantify how this fusion process changes with age. We show that, with age, the vestibular information is down-weighted whereas the visual weight is increased. This shift in sensory reweighting is primarily due to an age-related increase of the noise of vestibular signals.

scholarly journals Bayesian optimal adaptation explains age-related human sensorimotor changes

2018 ◽  
Vol 119 (2) ◽  
pp. 509-520 ◽  
Author(s):  
Faisal Karmali ◽  
Gregory T. Whitman ◽  
Richard F. Lewis
Keyword(s):  
Motor Behavior ◽  
Sensory Information ◽  
Bayesian Framework ◽  
Aging Brain ◽  
Vestibuloocular Reflex ◽  
Noise Characteristics ◽  
Age Related ◽  
Age Dependent ◽  
Optimal Adaptation ◽  
The Brain

The brain uses information from different sensory systems to guide motor behavior, and aging is associated with simultaneous decline in the quality of sensory information provided to the brain and deterioration in motor control. Correlations between age-dependent decline in sensory anatomical structures and behavior have been demonstrated in many sensorimotor systems, and it has recently been suggested that a Bayesian framework could explain these relationships. Here we show that age-dependent changes in a human sensorimotor reflex, the vestibuloocular reflex, are explained by a Bayesian optimal adaptation in the brain occurring in response to death of motion-sensing hair cells. Specifically, we found that the temporal dynamics of the reflex as a function of age emerge from ( r = 0.93, P < 0.001) a Kalman filter model that determines the optimal behavioral output when the sensory signal-to-noise characteristics are degraded by death of the transducers. These findings demonstrate that the aging brain is capable of generating the ideal and statistically optimal behavioral response when provided with deteriorating sensory information. While the Bayesian framework has been shown to be a general neural principle for multimodal sensory integration and dynamic sensory estimation, these findings provide evidence of longitudinal Bayesian processing over the human life span. These results illuminate how the aging brain strives to optimize motor behavior when faced with deterioration in the peripheral and central nervous systems and have implications in the field of vestibular and balance disorders, as they will likely provide guidance for physical therapy and for prosthetic aids that aim to reduce falls in the elderly.NEW & NOTEWORTHY We showed that age-dependent changes in the vestibuloocular reflex are explained by a Bayesian optimal adaptation in the brain that occurs in response to age-dependent sensory anatomical changes. This demonstrates that the brain can longitudinally respond to age-related sensory loss in an ideal and statistically optimal way. This has implications for understanding and treating vestibular disorders caused by aging and provides insight into the structure-function relationship during aging.

AGE-DEPENDENT CHANGES IN ADRENOREACTIVITY IN EXPERIMENTAL POSTINFARCTION CARDIOSCLEROSIS

2020 ◽  
pp. 729-734
Author(s):  
Т. Ю. Реброва ◽  
С. А. Афанасьев ◽  
М. О. Островик
Keyword(s):  
Adrenergic Receptors ◽  
Coronary Occlusion ◽  
The Body ◽  
Male Rats ◽  
Erythrocyte Membranes ◽  
Postinfarction Cardiosclerosis ◽  
Age Related ◽  
Age Dependent ◽  
Β Adrenergic Receptors ◽  
Intact Rats

В настоящее время возрастает интерес к изучению активности симпатико-адреналовой системы (САС) в процессе старения организма и развитию заболеваний сердечно-сосудистой системы, связанных с возрастом. Целью исследования стала оценка β-адренореактивности мембран эритроцитов (β-АРМ) у интактных животных и животных с постинфарктным кардиосклерозом (ПИКС) в трех возрастных группах: 1-я - 20 животных 4 мес; 2-я - 20 животных 12 мес; 3-я - 20 старых животных 24 мес. В каждой возрастной группе было выделено 10 интактных и 10 опытных животных, которым методом коронароокклюзии моделировали ПИКС. Эксперименты были выполнены на крысах-самцах линии Wistar . Показано, что у интактных животных показатель β-АРМ статистически значимо увеличивался в группе 12-месячных животных по отношению к группе 4-месячных. В группах 12-и 24-месячных интактных животных не было отмечено значимых различий показателя β-АРМ. Выраженность гипертрофии сердца у животных с ПИКС находилась в обратной зависимости от возраста - 4>12>24 мес. Сформировавшийся ПИКС у животных 4 и 12 мес сопровождался выраженным увеличением β-АРМ, у животных 24 мес с ПИКС β-АРМ значимо не изменялся. Изменения показателя β-АРМ, характеризующего состояние рецепторного звена САС, в условиях ПИКС имеют возрастные особенности: у взрослых 12-месячных особей при ПИКС увеличение β-АРМ относительно показателя у 4-месячных животных свидетельствует о компенсаторной десенситизации β-адренорецепторов при активации САС в ответ на развитие сократительной недостаточности миокарда. В группе 24-месячных животных при сформировавшемся кардиосклерозе компенсаторная активация САС проявлялась в меньшей степени. Presently, there is growing interest in studying the activity of the sympathoadrenal system in the aging process of the body and the development of diseases of the cardiovascular system associated with age. The intention of the research is evaluation of β-adrenoreactivity of erythrocyte membranes (β-ARM) of intact rats and rats with postinfarction cardiosclerosis at the age of 4, 12 and 24 months: the first group contained twenty 4 months old animals; the second group - twenty 12 months old animals; the third group - twenty 24 months old animals. In the each group were distinguish 10 intact rats and 10 experimental rats, that have postinfarction cardiosclerosis (PICS) modeled by coronary occlusion. The experiments was completed on 60 male-rats. It was shown, that in intact animals the indicator of β-ARM significantly decreases by 12 months in relation to the group of 4 monthly animals. In the groups of intact animals of 12 and 24 months, there were no significant differences in β-ARM. The severity of cardiac hypertrophy in animals with PICS was inversely related to age - 4>12>24 months old. Formed PICS in animals aged 4 and 12 months was accompanied by a expressed increase of β-ARM, in animals 24 months with PICS β-ARM did not significantly change. Changes in the β-ARM index characterizing the state of the CAS receptor link under PICS conditions are age-related, in adults 12 months of age with PICS, an increase in β-ARM relative to the parameter at 4 months. animals indicates compensatory desensitization of β-adrenergic receptors upon activation of CAS in response to the development of contractile myocardial insuffi ciency. In the age group of 24 months with the formed cardiosclerosis, compensatory activation of CAS is manifested to a lesser extent.

scholarly journals Dissociating vestibular and somatosensory contributions to spatial orientation

2016 ◽  
Vol 116 (1) ◽  
pp. 30-40 ◽  
Author(s):  
Bart B. G. T. Alberts ◽  
Luc P. J. Selen ◽  
Giovanni Bertolini ◽  
Dominik Straumann ◽  
W. Pieter Medendorp ◽  
...  
Keyword(s):  
Tilt Angle ◽  
Spatial Orientation ◽  
The Body ◽  
Substantial Contribution ◽  
Otolith Organs ◽  
Noise Levels ◽  
Healthy Human ◽  
Vestibular Loss ◽  
Bilateral Vestibular Loss ◽  
Noise Characteristics

Inferring object orientation in the surroundings heavily depends on our internal sense of direction of gravity. Previous research showed that this sense is based on the integration of multiple information sources, including visual, vestibular (otolithic), and somatosensory signals. The individual noise characteristics and contributions of these sensors can be studied using spatial orientation tasks, such as the subjective visual vertical (SVV) task. A recent study reported that patients with complete bilateral vestibular loss perform similar as healthy controls on these tasks, from which it was conjectured that the noise levels of both otoliths and body somatosensors are roll-tilt dependent. Here, we tested this hypothesis in 10 healthy human subjects by roll tilting the head relative to the body to dissociate tilt-angle dependencies of otolith and somatosensory noise. Using a psychometric approach, we measured the perceived orientation, and its variability, of a briefly flashed line relative to the gravitational vertical (SVV). Measurements were taken at multiple body-in-space orientations (−90 to 90°, steps of 30°) and head-on-body roll tilts (30° left ear down, aligned, 30° right ear down). Results showed that verticality perception is processed in a head-in-space reference frame, with a systematic SVV error that increased with larger head-in-space orientations. Variability patterns indicated a larger contribution of the otolith organs around upright and a more substantial contribution of the body somatosensors at larger body-in-space roll tilts. Simulations show that these findings are consistent with a statistical model that involves tilt-dependent noise levels of both otolith and somatosensory signals, confirming dynamic shifts in the weights of sensory inputs with tilt angle.

The influence of osteopathic correction on the rate of various rhythms of the body

2019 ◽  
pp. 64-71 ◽  
Author(s):  
A. E. Chernikova ◽  
Yu. P. Potekhina
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Age Groups ◽  
Biomechanical Properties ◽  
Dispersion Analysis ◽  
The Body ◽  
Body Tissues ◽  
Age Related ◽  
Significant Difference ◽  
Before And After

Introduction. An osteopathic examination determines the rate, the amplitude and the strength of the main rhythms (cardiac, respiratory and cranial). However, there are relatively few studies in the available literature dedicated to the influence of osteopathic correction (OC) on the characteristics of these rhythms.Goal of research — to study the influence of OC on the rate characteristics of various rhythms of the human body.Materials and methods. 88 adult osteopathic patients aged from 18 to 81 years were examined, among them 30 men and 58 women. All patients received general osteopathic examination. The rate of the cranial rhythm (RCR), respiratory rate (RR) heart rate (HR), the mobility of the nervous processes (MNP) and the connective tissue mobility (CTM) were assessed before and after the OC session.Results. Since age varied greatly in the examined group, a correlation analysis of age-related changes of the assessed rhythms was carried out. Only the CTM correlated with age (r=–0,28; p<0,05) in a statistically significant way. The rank dispersion analysis of Kruskal–Wallis also showed statistically significant difference in this indicator in different age groups (p=0,043). With the increase of years, the CTM decreases gradually. After the OC, the CTM, increased in a statistically significant way (p<0,0001). The RCR varied from 5 to 12 cycles/min in the examined group, which corresponded to the norm. After the OC, the RCR has increased in a statistically significant way (p<0,0001), the MNP has also increased (p<0,0001). The initial heart rate in the subjects varied from 56 to 94 beats/min, and in 15 % it exceeded the norm. After the OC the heart rate corresponded to the norm in all patients. The heart rate and the respiratory rate significantly decreased after the OC (р<0,0001).Conclusion. The described biorhythm changes after the OC session may be indicative of the improvement of the nervous regulation, of the normalization of the autonomic balance, of the improvement of the biomechanical properties of body tissues and of the increase of their mobility. The assessed parameters can be measured quickly without any additional equipment and can be used in order to study the results of the OC.

PERMEABILITY OF CELLS AND ITS IMPORTANCE IN ASSESSMENT OF FISHES AGE

1970 ◽  
pp. 70-73
Author(s):  
N. I. Maslova
Keyword(s):  
Cholesterol Content ◽  
The Body ◽  
Cellular Structures ◽  
Ratio Estimation ◽  
Carbohydrate Diet ◽  
Spawning Period ◽  
Age Related ◽  
Experimental Base ◽  
Cellular Permeability ◽  
Membrane Strength

The article presents analysis of material and results of their own studies on changes in the permeability of cellular structures, organs and tissues in carp, which is of great importance in determining age-related indicators. The cells permeability in liver and gonads estimation was carried out under the experimental base of VNIIR on two carp genotypes during the pre-spawning period. The carp groups taken for analysis differed significantly in their genotypes. In females of the Khrapunov group the fecundity was 2023.0 thousand units, while the number of oocytes filled with yolk was only 0.7%, in the Ostashevsky ones - 1370.0 thousand units and 8.6%, respectively. During estimation the chemical composition of the generative tissue in females and males it was established that the cholesterol and lecithin content in males is higher than that of females, while feeding dependence is observed, especially on the amount of protein in the diet. For example, in females on protein diet contained less glycogen in gonads than on females on carbohydrate diet. Lecithin and cholesterol are higher in males than in females, which corresponds to increasing the Gyurdy Ratio (estimation of cell membrane strength). In spermatogenesis the content of phospholipids and cholesterol in the liver was decreased less than during ovogenesis. This indicates a lower level of synthetic processes in the milts compared with the ovaries. The cholesterol content in sperm is higher than in caviar in 19.6 times, and phospholipids almost doubled. With increasing age, the Gyordy Ratio for caviar decreases, for sperm it increases, the percentage of caviar fertilization increases. As the body age metabolism deteriorates, cellular permeability decreases (the ratio of lecithin and cholesterol changes significantly). At the same time, the permeability of cells in different organs and tissues varies and depends on living conditions, especially feeding and to some extent on the origin. In fish the gross productivity decreases as growth slows down and more energy is spent on adaptation to environmental conditions.

scholarly journals Fighting Oxidative Stress with Sulfur: Hydrogen Sulfide in the Renal and Cardiovascular Systems

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 373
Author(s):  
Joshua J. Scammahorn ◽  
Isabel T. N. Nguyen ◽  
Eelke M. Bos ◽  
Harry Van Goor ◽  
Jaap A. Joles
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Sulfide ◽  
Redox Status ◽  
The Body ◽  
Therapeutic Interventions ◽  
Oxygen Species ◽  
Enzymatic Production ◽  
Age Related ◽  
Anti Oxidant ◽  
Enzymatic Pathways

Hydrogen sulfide (H2S) is an essential gaseous signaling molecule. Research on its role in physiological and pathophysiological processes has greatly expanded. Endogenous enzymatic production through the transsulfuration and cysteine catabolism pathways can occur in the kidneys and blood vessels. Furthermore, non-enzymatic pathways are present throughout the body. In the renal and cardiovascular system, H2S plays an important role in maintaining the redox status at safe levels by promoting scavenging of reactive oxygen species (ROS). H2S also modifies cysteine residues on key signaling molecules such as keap1/Nrf2, NFκB, and HIF-1α, thereby promoting anti-oxidant mechanisms. Depletion of H2S is implicated in many age-related and cardiorenal diseases, all having oxidative stress as a major contributor. Current research suggests potential for H2S-based therapies, however, therapeutic interventions have been limited to studies in animal models. Beyond H2S use as direct treatment, it could improve procedures such as transplantation, stem cell therapy, and the safety and efficacy of drugs including NSAIDs and ACE inhibitors. All in all, H2S is a prime subject for further research with potential for clinical use.

scholarly journals The serotonin transporter gene and female personality variation in a free-living passerine

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bert Thys ◽  
Andrea S. Grunst ◽  
Nicky Staes ◽  
Rianne Pinxten ◽  
Marcel Eens ◽  
...  
Keyword(s):  
Serotonin Transporter ◽  
Strong Support ◽  
Serotonin Transporter Gene ◽  
Female Aggression ◽  
Nucleotide Polymorphisms ◽  
Transporter Gene ◽  
Evolutionary Potential ◽  
Free Living ◽  
Age Related ◽  
Age Dependent

AbstractQuantifying variation in behaviour-related genes provides insight into the evolutionary potential of repeatable among-individual variation in behaviour (i.e. personality). Yet, individuals typically also plastically adjust their behaviour in response to environmental conditions and/or age, thereby complicating the detection of genotype–phenotype associations. Here, using a population of free-living great tits (Parus major), we assessed the association between single nucleotide polymorphisms (SNPs) in the serotonin transporter gene (SERT) and two repeatable behavioural traits, i.e. female-female aggression and female hissing behaviour. For female-female aggression, a trait showing age-related plasticity, we found no evidence for associations with SERT SNPs, even when assessing potential age-dependent effects of SERT genotype on aggression. We also found no strong support for associations between SERT SNPs and hissing behaviour, yet we identified two synonymous polymorphisms (exon 13 SNP66 and exon 12 SNP144) of particular interest, each explaining about 1.3% of the total variation in hissing behaviour. Overall, our results contribute to the general understanding of the biological underpinning of complex behavioural traits and will facilitate further (meta-analytic) research on behaviour-related genes. Moreover, we emphasize that future molecular genetic studies should consider age-dependent genotype–phenotype associations for behavioural trait (co)variation, as this will vastly improve our understanding of the proximate causes and ultimate consequences of personality variation in natural populations.

scholarly journals The prevalence of obesity in older adults in Iran: a systematic review and meta-analysis

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Aliakbar Vaisi-Raygani ◽  
Masoud Mohammadi ◽  
Rostam Jalali ◽  
Akram Ghobadi ◽  
Nader Salari
Keyword(s):  
Systematic Review ◽  
Older Adults ◽  
Older Adult ◽  
Meta Analysis ◽  
The Body ◽  
Obesity Prevalence ◽  
Analysis Software ◽  
Obesity And Overweight ◽  
Age Dependent ◽  
Prevalence Of Obesity

Abstract Background one of the most important age-dependent physiologic alterations in the body composition of older adult people is obesity and overweight, increasing the risk of cardiovascular disease and mortality rate. Objective The aim of the present study is to determine the prevalence of obesity in older adults in Iran. Methods The present study was conducted via meta-analysis and systematic review method, from March 2000 to October 2018. Subject-related literature was obtained via searches in ScienceDirect, Medline (PubMed), SID, Magiran, Scopus, and Google Scholar databases. Heterogeneity of studies was assessed using the I2 index, and data were analyzed by Comprehensive-Meta analysis software. Results In the assessment of 18 studies and 29,943 persons aged over 50 years, the prevalence of obesity in older adults of Iran was 21.4% (95%CI: 26.6–16.9%) based on the meta-analysis. The highest obesity prevalence was obtained in older adults of Babol (Amir Shahr) which was 44.2% (95%CI: 41.1–47.2%) in 2007, while the minimum obesity prevalence was found in older adults of Razavi Khorasan which was 11.3% (95%CI, 10–12.8%) in 2007. Further, as the sample size and the study year increased, the obesity prevalence diminished in older Iranian adults (p < 0.05). Conclusion This study suggests that the prevalence of obesity in the older adults of Iran is high. Accordingly, healthcare planners and politicians should consider effective and practical policies to reduce obesity in older adults.

scholarly journals Random errors in protein synthesis activate an age-dependent program of muscle atrophy in mice

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
James Moore ◽  
Rashid Akbergenov ◽  
Martina Nigri ◽  
Patricia Isnard-Petit ◽  
Amandine Grimm ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Muscle Atrophy ◽  
Strength Analysis ◽  
Dependent Manner ◽  
Random Errors ◽  
Age Related ◽  
Related Phenotype ◽  
Age Dependent ◽  
Translation Accuracy ◽  
Transcriptomic Changes

AbstractRandom errors in protein synthesis are prevalent and ubiquitous, yet their effect on organismal health has remained enigmatic for over five decades. Here, we studied whether mice carrying the ribosomal ambiguity (ram) mutation Rps2-A226Y, recently shown to increase the inborn error rate of mammalian translation, if at all viable, present any specific, possibly aging-related, phenotype. We introduced Rps2-A226Y using a Cre/loxP strategy. Resulting transgenic mice were mosaic and showed a muscle-related phenotype with reduced grip strength. Analysis of gene expression in skeletal muscle using RNA-Seq revealed transcriptomic changes occurring in an age-dependent manner, involving an interplay of PGC1α, FOXO3, mTOR, and glucocorticoids as key signaling pathways, and finally resulting in activation of a muscle atrophy program. Our results highlight the relevance of translation accuracy, and show how disturbances thereof may contribute to age-related pathologies.

scholarly journals Age-Related, Sport-Specific Adaptions of the Shoulder Girdle in Elite Adolescent Tennis Players

2014 ◽  
Vol 49 (5) ◽  
pp. 647-653 ◽  
Author(s):  
Ann M. Cools ◽  
Tanneke Palmans ◽  
Fredrik R. Johansson
Keyword(s):  
Muscle Strength ◽  
Shoulder Girdle ◽  
Vital Role ◽  
The Body ◽  
Injury Incidence ◽  
Shoulder Injury ◽  
Serratus Anterior ◽  
Cross Sectional ◽  
Tennis Players ◽  
Age Related

Context Tennis requires repetitive overhead movements that can lead to upper extremity injury. The scapula and the shoulder play a vital role in injury-free playing. Scapular dysfunction and glenohumeral changes in strength and range of motion (ROM) have been associated with shoulder injury in the overhead athlete. Objective To compare scapular position and strength and shoulder ROM and strength between Swedish elite tennis players of 3 age categories (&lt;14, 14–16, and &gt;16 years). Design Cross-sectional study. Setting Tennis training sports facilities. Patients or Other Participants Fifty-nine adolescent Swedish elite tennis players (ages 10–20 years) selected based on their national ranking. Main Outcome Measure(s) We used a clinical screening protocol with a digital inclinometer and a handheld dynamometer to measure scapular upward rotation at several angles of arm elevation, isometric scapular muscle strength, glenohumeral ROM, and isometric rotator cuff strength. Results Players older than 16 years showed less scapular upward rotation on the dominant side at 90° and 180° (P &lt; .05). Although all absolute scapular muscle strength values increased with age, there was no change in the body-weight–normalized strength of the middle (P = .9) and lower (P = .81) trapezius or serratus anterior (P = .17). Glenohumeral internal-rotation ROM and total ROM tended to decrease, but this finding was not statistically significant (P = .052 and P = .06, respectively). Whereas normalized internal-rotator strength increased from 14 to 16 years to older than 16 years (P = .009), normalized external-rotator and supraspinatus strength remained unchanged. Conclusions Age-related changes in shoulder and scapular strength and ROM were apparent in elite adolescent tennis players. Future authors should examine the association of these adaptations with performance data and injury incidence.

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