激活后的强化和强化的运动单元在男孩和男人的发射模式
Andrew McKiel1,2, Stacey Woods1,2, David A Gabriel1
1Department of Kinesiology, Brock University, St. Catharines, ON, L2S 3A1, Canada.
European journal of applied physiology
|December 30, 2023
概括
男孩的活化后强化 (PAP) 比男性低,尽管在强化后的高强度收缩期间,运动单元发射率 (MUFRs) 的降低更大.
科学领域:
- 运动生理学 运动生理学
- 神经肌肉生理学 神经肌肉生理学
背景情况:
- 后激活强化 (PAP) 增加了肌肉扭矩后的条件收缩 (CC).
- 成人PAP与肌肉纤维组成和运动单元发射率 (MUFRs) 的降低有关.
- 儿童的肌肉生理与成年人不同,需要对与年龄相关的PAP和MU激活进行研究.
研究的目的:
- 为了研究膝盖延伸器的PAP与年龄相关的差异.
- 为了检查运动单元 (MU) 在男孩和男人的强化期间的发射模式.
主要方法:
- 23名男孩 (10.5岁) 和20名男性 (23.1岁) 接受了测试.
- 测量了CC前后的最大同位数引起的扭矩和MU发射模式 (20%和70% MVIC).
- 表面电肌图和分解算法分析了MU动作潜能幅度 (MUAPamp) 和MUFRs.
主要成果:
- 男性的PAP (98.3%) 比男孩 (68.8%) 高得多.
- 在两组中,增强降低了MUFR-MUAPamp关系的衰变率.
- 与男性相比,男孩在强化后的高强度收缩期间,MUFR的下降幅度更大.
结论:
- 与男性相比,男孩表现出较低的PAP.
- 尽管PAP较低,但男孩体验到MUFR的显著降低与强化,特别是在高强度收缩期间.
- 在神经肌肉对强化反应的年龄相关差异是显而易见的.
相关概念视频
Long-term Potentiation
2.8K
Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory.
Hebbian LTP
LTP can occur when...
Hebbian LTP
LTP can occur when...
2.8K
Motor Unit Stimulation
1.6K
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...
1.6K
Muscle Stimulation Frequency
2.2K
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...
2.2K
Action Potential
8.0K
Neurons communicate by firing action potentials—the electrochemical signal that is propagated along the axon. The signal results in the release of neurotransmitters at axon terminals, thereby transmitting information to the nervous system. An action potential is a specific "all-or-none" change in membrane potential that results in a rapid spike in voltage.
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they...
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they...
8.0K
Generation of Action Potential in Skeletal Muscles
4.5K
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...
4.5K


