The processing of proprioceptive signals in distributed networks: insights from insect motor control

Journal of Experimental Biology, Journal Year: 2024, Volume and Issue: 227(1)

Published: Jan. 1, 2024

ABSTRACT The integration of sensory information is required to maintain body posture and generate robust yet flexible locomotion through unpredictable environments. To anticipate adaptations in limb enable compensation sudden perturbations, an animal's nervous system assembles external (exteroception) internal (proprioception) cues. Coherent neuronal representations the proprioceptive context appendages arise from concerted action multiple sense organs monitoring kinetics kinematics. This multimodal information, together with exteroceptive signals brain-derived descending motor commands, converges onto premotor networks – i.e. local circuitry controlling output movements within ventral nerve cord (VNC), insect equivalent vertebrate spinal cord. Review summarizes existing knowledge recent advances understanding how VNC use convergent contextually appropriate activity, focusing on example control. We compare role advantages distributed processing over dedicated pathways, challenges networks. discuss gain may be tuned behavioral repertoire these systems, argue that might compensate for their limited population size by, comparison networks, relying more heavily specificity connections. At a time which connectomics physiological recording techniques anatomical functional circuit dissection at unprecedented resolution, systems offer unique opportunities identify mechanisms underlying

Language: Английский

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Spatiotemporal modulation of a common set of muscle synergies during unpredictable and predictable gait perturbations in older adults

Journal of Experimental Biology, Journal Year: 2024, Volume and Issue: 227(7)

Published: March 20, 2024

Muscle synergies as functional low-dimensional building blocks of the neuromotor system regulate activation patterns muscle groups in a modular structure during locomotion. The purpose current study was to explore how older adults organize locomotor counteract unpredictable and predictable gait perturbations perturbed steps recovery steps. Sixty-three healthy (71.2±5.2 years) participated study. Mediolateral anteroposterior walking were introduced using treadmill. extracted from electromyographic activity 13 lower limb muscles Gaussian non-negative matrix factorization. four basic responsible for unperturbed (weight acceptance, propulsion, early swing late swing) preserved all applied perturbations, yet their temporal recruitment contribution each synergy modified (P<0.05). These modifications observed up more pronounced (P<0.05) following perturbations. cycles indicates robust control locomotion by few well-known with specific adjustments within synergies. selection pre-existing while adjusting time challenging conditions may improve effectiveness deal promote transfer adaptation between different kinds

Language: Английский

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Passive responses in mouse hind leg locomotion

Current Biology, Journal Year: 2025, Volume and Issue: unknown

Published: March 1, 2025

Language: Английский

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Muscle spindle afferent neurons preferentially degenerate with aging

Published: May 2, 2025

Muscle spindles sense changes inmuscle length and transmit them to the central nervous system. Proprioception is essential for gait postural maintenance, abnormality of which has been linked disorders risk falling in older adults. However, effects aging on muscle spindle structure remain nebulous. This study investigated age-related structural themuscle (from equator polar) soleus extensor digitorum longus (EDL) muscles young, middle-aged, aged mice. The findings indicated that shape annulospiral endings sensory neurons began deteriorate middle-aged compared with young mice was further exacerbated These were particularly pronounced nuclear bag fibers, whereas no significant observed intrafusal fibers or capsules. A decline function due weight-bearing weight-shifting also observed, suggesting deterioration proprioceptive innervate fiber responsible dynamic sensitivity prevents proper coordinated movement contributes animals including humans, together functional extrafusal fibers.

Language: Английский

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The Influence of Knee Proprioception and Strength on Lower-Limb Functional Symmetry in Healthy Adults

Muscles, Journal Year: 2025, Volume and Issue: 4(1), P. 3 - 3

Published: Jan. 21, 2025

This study examined the association between knee proprioception, strength, and functional symmetry in healthy individuals using isokinetic strength tests, proprioception assessments, hop tests. Twenty young, adults (mean age 26.5 ± 4.1 years, 85% right-limb dominant) participated. Knee extensor flexor were measured at 60°·s−1 240°·s−1. Proprioception was assessed by measuring passive joint position sense (JPS1: recognition; JPS2: repositioning) kinesthesia (threshold to detection of motion, TTDPM). Functional performance evaluated single-leg test (SLH), triple-hop (TH), crossover (COH). Symmetry calculated limb index (LSI) as ratio non-dominant dominant values. The results showed that THT (p = 0.011) COH 0.032) superior on limb. A correlation analysis revealed strong positive correlations distances (r 0.56–0.70, p < 0.001). JPS negatively correlated with SLH, r −0.53; THT, −0.49; COH, −0.70). participants poorer leg 2.7 times more likely show LSI 90% 0.035). In conclusion, proprioception—particularly sense—is associated during dynamic tasks, highlighting importance proprioceptive assessments rehabilitation injury prevention.

Language: Английский

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Intramuscular tendon length in agonist–antagonist myoneural interface components in transtibial amputation: An anatomic study

Journal of Anatomy, Journal Year: 2025, Volume and Issue: unknown

Published: May 9, 2025

Abstract Understanding the role of tendons in muscle function and proprioception is crucial for enhancing amputation surgery. Muscle spindles Golgi tendon organs provide essential feedback control. Preservation surgery development agonist–antagonist myoneural interface ( AMI ) have shown promising results restoring muscle–tendon improving prosthetic However, challenges remain constructing due to anatomical limitations residual limbs. A total 25 lower legs from fresh‐frozen human Caucasian donors were dissected, muscles relevant technique, such as gastrocnemius complex, tibialis posterior, anterior, peroneus longus, analyzed. Demographic anthropometric measurements, preparation weight, markings, imaging, statistical analysis methods described detail. In all examined, intramuscular course extended over more than 75% distal belly. The belly length longus medial head showed a significant positive correlation with weight height donors. There no correlations between ratio or donor. technique can enhance proprioceptive transtibial amputees wearing prostheses. study indicates that gender does not impact characteristics, but show correlations. These offer valuable insights into anatomy informing future research on functional effects limb design.

Language: Английский

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Time-Varying Functional Connectivity of Rat Brain during Bipedal Walking on Unexpected Terrain

Cyborg and Bionic Systems, Journal Year: 2023, Volume and Issue: 4

Published: Jan. 1, 2023

The cerebral cortex plays an important role in human and other animal adaptation to unpredictable terrain changes, but little was known about the functional network among cortical areas during this process. To address question, we trained 6 rats with blocked vision walk bipedally on a treadmill random uneven area. Whole-brain electroencephalography signals were recorded by 32-channel implanted electrodes. Afterward, scan from all using time windows quantify connectivity within each window phase-lag index. Finally, machine learning algorithms used verify possibility of dynamic analysis detecting locomotion state rats. We found that level higher preparation phase compared walking phase. In addition, pays more attention control hind limbs requirements for muscle activity. lower where ahead can be predicted. Functional bursts after rat accidentally made contact terrain, while subsequent movement, it significantly than normal walking. classification results show index multiple gait phases as feature effectively detect states These highlight animals unexpected may help advance motor studies design neuroprostheses.

Language: Английский

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Mechanosensory Control of Locomotion in Animals and Robots: Moving Forward

Integrative and Comparative Biology, Journal Year: 2023, Volume and Issue: 63(2), P. 450 - 463

Published: June 5, 2023

While animals swim, crawl, walk, and fly with apparent ease, building robots capable of robust locomotion remains a significant challenge. In this review, we draw attention to mechanosensation-the sensing mechanical forces generated within outside the body-as key sense that enables in animals. We discuss differences between mechanosensation current respect (1) encoding properties distribution mechanosensors (2) integration regulation mechanosensory feedback. argue robotics would benefit greatly from detailed understanding these aspects To end, highlight promising experimental engineering approaches study mechanosensation, emphasizing mutual benefits for biologists engineers emerge moving forward together.

Language: Английский

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Muscle synergies inherent in simulated hypogravity running reveal flexible but not unconstrained locomotor control

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: Feb. 1, 2024

Abstract With human space exploration back in the spotlight, recent studies have investigated neuromuscular adjustments to simulated hypogravity running. They examined activity of individual muscles, whereas central nervous system may rather activate groups functionally related known as muscle synergies. To understand how locomotor control adjusts hypogravity, we temporal (motor primitives) and spatial modules) components synergies participants running sequentially at 100%, 60%, 100% body weight on a treadmill. Our results highlighted paradoxical nature running: The reduced mechanical constraints allowed for more flexible control, which correlated with degree spatiotemporal adjustments. Yet, increased (shortened stance phase) sensory (deteriorated proprioceptive feedback) required wider motor primitives higher contribution hamstring muscles during phase. These are first step towards improving astronaut training protocols.

Language: Английский

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Muscle spindles and their role in maintaining robust locomotion

The Journal of Physiology, Journal Year: 2022, Volume and Issue: 601(2), P. 275 - 285

Published: Dec. 13, 2022

Muscle spindles, one of the two main classes proprioceptors together with Golgi tendon organs, are sensory structures that keep central nervous system updated about position and movement body parts. Although they were discovered more than 150 years ago, their function during is not yet fully understood. Here, we summarize morphology known functions muscle a particular focus on locomotion. certain properties such as sensitivity to dynamic static stretch long known, recent advances in molecular biology have allowed characterization mechanisms for signal transduction spindles. Building upon classic literature showing lack feedback deleterious locomotion, bring discussion findings support pivotal role spindles maintaining murine human locomotor robustness, defined ability cope perturbations. Yet, research needed expand existing mechanistic understanding how contribute production robust, functional locomotion real world settings. Future investigations should combining different animal models identify, health disease, those peripheral, spinal brain proprioceptive involved fine tuning motor control when happens challenging conditions.

Language: Английский

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