较高的主导肌肉力量是由运动单元放电率和常见突触输入的比例介导的
Edoardo Lecce1, Alessandro Del Vecchio2, Stefano Nuccio1
1Laboratory of Exercise Physiology, Department of Movement, Human, and Health Sciences, University of Rome "Foro Italico", Rome, Italy.
Scientific reports
|March 11, 2025
概括
主导肢体表现出更大的最大自愿力 (MVF),这是由于来自常见突触输入的神经驱动增加,而不是变化的运动神经元特性. 这突显了肢体主导的基础的神经不对称性.
科学领域:
- 神经科学是一个神经科学.
- 发动机控制器的控制器
- 人体生理学 人体生理学
背景情况:
- 肢体优势涉及不对称的力量和技能,但神经支仍然不清楚.
- 了解肢体优势的神经控制对于体育科学和康复等领域至关重要.
研究的目的:
- 调查四肢主导中的力量和技能不对称性的神经决定因素.
- 为了比较主导和非主导四肢之间的运动单元放电特征和突触输入.
主要方法:
- 高密度表面电肌图记录了在异度收缩期间的双臂肌活动.
- 分析了最大自愿力 (MVF),运动单元放电率和共同的突触输入.
- 脊柱运动神经元的内在性质是使用发射速率歇斯底里 (∆F) 来估计的.
主要成果:
- 占主导地位的四肢显示出明显更高的MVF (+9%) 和更高的运动单元放电率.
- 在占主导地位的肢体中观察到更大比例的共同突触输入 (+14%).
- 在动力单元招聘/退聘门或∆F方面没有发现显著差异.
结论:
- 占主导地位的四肢更强大与神经驱动力增加有关,特别是通过增强对运动神经元的共同突触输入来增加神经驱动力.
- 在运动单元水平上的神经不对称性有助于在肢体主导中观察到的机械输出差异.
- 研究结果表明神经驱动,而不是内在的运动神经元特性,主要解释四肢主导强度差异.
相关概念视频
Motor Unit Stimulation
1.3K
When the neuron of a motor unit fires an action potential, it triggers a series of events, leading to a twitch contraction in the muscle fibers. The process of excitation-contraction coupling is crucial in relaying the action potential to the muscle fibers.
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
1.3K
Muscle Stimulation Frequency
1.9K
The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box.
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
1.9K
Motor Units
3.6K
The motor unit is a fundamental component of the neuromuscular system and plays a crucial role in coordinating muscle contractions. It consists of a somatic motor neuron, which connects and controls multiple skeletal muscle fibers, forming a single functional segment. The axon of the motor neuron branches out and establishes synaptic connections known as neuromuscular junctions with individual muscle fibers within the motor unit.
Motor units come in different sizes, with smaller units...
Motor units come in different sizes, with smaller units...
3.6K
Relaxation of Skeletal Muscles
3.0K
The period of muscle contraction primarily influences the duration of stimulation at the neuromuscular junction (NMJ), the presence of free calcium ions in the sarcoplasm, and the availability of energy or ATP to support contractions.
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open....
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open....
3.0K
Muscle Contraction
89.8K
89.8K
Generation of Action Potential in Skeletal Muscles
4.0K
Every cell in the body maintains a membrane potential due to an uneven distribution of positive and negative charges across its plasma membrane. The membrane potential is measured in millivolts and quantifies the difference in charge across the membrane.
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the...
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the...
4.0K


