scholarly journals Fundamental constraints in synchronous muscle limit superfast motor control in vertebrates

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Andrew F Mead ◽  
Nerea Osinalde ◽  
Niels Ørtenblad ◽  
Joachim Nielsen ◽  
Jonathan Brewer ◽  
...  
Keyword(s):  
Motor Control ◽  
Fine Motor ◽  
Maximum Speed ◽  
Motor Execution ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
Fundamental Limit ◽  
Crossbridge Kinetics ◽  
Millisecond Time Scale ◽  
Myosin Heavy Chain Genes

Superfast muscles (SFMs) are extremely fast synchronous muscles capable of contraction rates up to 250 Hz, enabling precise motor execution at the millisecond time scale. SFM phenotypes have been discovered in most major vertebrate lineages, but it remains unknown whether all SFMs share excitation-contraction coupling pathway adaptations for speed, and if SFMs arose once, or from independent evolutionary events. Here, we demonstrate that to achieve rapid actomyosin crossbridge kinetics bat and songbird SFM express myosin heavy chain genes that are evolutionarily and ontologically distinct. Furthermore, we show that all known SFMs share multiple functional adaptations that minimize excitation-contraction coupling transduction times. Our results suggest that SFM evolved independently in sound-producing organs in ray-finned fish, birds, and mammals, and that SFM phenotypes operate at a maximum operational speed set by fundamental constraints in synchronous muscle. Consequentially, these constraints set a fundamental limit to the maximum speed of fine motor control.

scholarly journals Fundamental constraints in synchronous muscle limit superfast motor control in vertebrates

2017 ◽  
Author(s):  
AF Mead ◽  
N. Osinalde ◽  
N. Ørtenblad ◽  
J. Nielsen ◽  
J. Brewer ◽  
...  
Keyword(s):  
Motor Control ◽  
Genomic Analysis ◽  
Fine Motor ◽  
Calcium Signal ◽  
Maximum Speed ◽  
Force Measurements ◽  
Motor Execution ◽  
Crossbridge Kinetics ◽  
Millisecond Time Scale ◽  
Myosin Heavy Chain Genes

Superfast muscles (SFM) are extremely fast synchronous muscles capable of contraction rates up to 250 Hz, enabling precise motor execution at the millisecond time scale. To allow such speed, the archetypal SFM, found in the toadfish swimbladder, has hallmark structural and kinetic adaptations at each step of the conserved excitation-contraction coupling (ECC) pathway. More recently SFM phenotypes have been discovered in most major vertebrate lineages, but it remains unknown whether all SFM share ECC adaptations for speed, and if SFM arose once, or from independent evolutionary events. Here we use genomic analysis to identify the myosin heavy chain genes expressed in bat and songbird SFM to achieve rapid actomyosin crossbridge kinetics and demonstrate that these are evolutionarily and ontologically distinct. Furthermore, by quantifying cellular morphometry and calcium signal transduction combined with force measurements we show that all known SFM share multiple functional adaptations that minimize ECC transduction times. Our results suggest that SFM evolved independently in sound producing organs in ray-finned fish, birds, and mammals, and that SFM phenotypes operate at a maximum operational speed set by fundamental constraints in synchronous muscle. Consequentially, these constraints set a fundamental limit to the maximum speed of fine motor control.

scholarly journals Remodeling of t-system and proteins underlying excitation-contraction coupling in aging versus failing human heart

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yankun Lyu ◽  
Vipin K. Verma ◽  
Younjee Lee ◽  
Iosif Taleb ◽  
Rachit Badolia ◽  
...  
Keyword(s):  
Heart Function ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Excitation Contraction Coupling ◽  
Transverse Tubular System ◽  
Contraction Coupling ◽  
Senescent Phenotype ◽  
Cellular Microstructure ◽  
T System

AbstractIt is well established that the aging heart progressively remodels towards a senescent phenotype, but alterations of cellular microstructure and their differences to chronic heart failure (HF) associated remodeling remain ill-defined. Here, we show that the transverse tubular system (t-system) and proteins underlying excitation-contraction coupling in cardiomyocytes are characteristically remodeled with age. We shed light on mechanisms of this remodeling and identified similarities and differences to chronic HF. Using left ventricular myocardium from donors and HF patients with ages between 19 and 75 years, we established a library of 3D reconstructions of the t-system as well as ryanodine receptor (RyR) and junctophilin 2 (JPH2) clusters. Aging was characterized by t-system alterations and sarcolemmal dissociation of RyR clusters. This remodeling was less pronounced than in HF and accompanied by major alterations of JPH2 arrangement. Our study indicates that targeting sarcolemmal association of JPH2 might ameliorate age-associated deficiencies of heart function.

scholarly journals Evaluation of Child–Computer Interaction Using Fitts’ Law: A Comparison between a Standard Computer Mouse and a Head Mouse

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3826
Author(s):  
Cristina Sanchez ◽  
Vanina Costa ◽  
Rodrigo Garcia-Carmona ◽  
Eloy Urendes ◽  
Javier Tejedor ◽  
...  
Keyword(s):  
Motor Control ◽  
Inertial Sensor ◽  
Psychomotor Development ◽  
Fine Motor ◽  
Input Devices ◽  
Fitts Law ◽  
Computer Mouse ◽  
Adults And Children ◽  
Study Participants ◽  
Computer Interaction

This study evaluates and compares the suitability for child–computer interaction (CCI, the branch within human–computer interaction focused on interactive computer systems for children) of two devices: a standard computer mouse and the ENLAZA interface, a head mouse that measures the user’s head posture using an inertial sensor. A multidirectional pointing task was used to assess the motor performance and the users’ ability to learn such a task. The evaluation was based on the interpretation of the metrics derived from Fitts’ law. Ten children aged between 6 and 8 participated in this study. Participants performed a series of pre- and post-training tests for both input devices. After the experiments, data were analyzed and statistically compared. The results show that Fitts’ law can be used to detect changes in the learning process and assess the level of psychomotor development (by comparing the performance of adults and children). In addition, meaningful differences between the fine motor control (hand) and the gross motor control (head) were found by comparing the results of the interaction using the two devices. These findings suggest that Fitts’ law metrics offer a reliable and objective way of measuring the progress of physical training or therapy.

scholarly journals Circle drawing and tracing dataset for evaluation of fine motor control

Data in Brief ◽  
2021 ◽  
Vol 35 ◽  
pp. 106763
Author(s):  
Eros Quarta ◽  
Riccardo Bravi ◽  
Diego Minciacchi ◽  
Erez James Cohen
Keyword(s):  
Motor Control ◽  
Fine Motor ◽  
Fine Motor Control ◽  
Circle Drawing

Hand fine motor control in classic galactosemia

2021 ◽  
Author(s):  
Jessica MacWilliams ◽  
Sneh Patel ◽  
Grace Carlock ◽  
Sarah Vest ◽  
Nancy L. Potter ◽  
...  
Keyword(s):  
Motor Control ◽  
Fine Motor ◽  
Fine Motor Control ◽  
Classic Galactosemia
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