Related Experiment Video
Updated: Mar 11, 2026
08:29
Assessment of Myofilament Ca2+ Sensitivity Underlying Cardiac Excitation-contraction Coupling
Published on: August 1, 2016
10.0K
Excitation-Contraction Coupling Alterations in Myopathies.
Isabelle Marty1,2, Julien Fauré1,2,3
1University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, F-38000 Grenoble, France.
Journal of Neuromuscular Diseases
|December 3, 2016
Summary
Muscle contraction relies on excitation-contraction coupling, a process involving calcium release. Dysfunctions in this calcium-release complex can cause muscle diseases, categorized by genetic mutations or structural/regulatory changes.
Area of Science:
- Muscle physiology
- Molecular biology
- Cellular biology
Background:
- Muscle contraction is initiated by electrical signals from motor neurons, leading to increased intracellular calcium.
- Excitation-contraction coupling precisely regulates calcium release within specialized muscle cell compartments called triads.
- Disruptions in the calcium-release complex or triad structure impair muscle function, causing myopathies.
Purpose of the Study:
- To review and classify the causes of muscle diseases linked to excitation-contraction coupling dysfunction.
- To discuss the pathophysiologic mechanisms underlying these muscle disorders.
Main Methods:
- Literature review and classification of muscle diseases based on the underlying cause of excitation-contraction coupling alteration.
- Discussion of current knowledge on pathophysiologic mechanisms for each disease category.
Main Results:
- Muscle diseases associated with excitation-contraction coupling dysfunction are categorized into four main groups.
- Categories include mutations in calcium-release complex proteins, triad structural alterations, channel regulation modifications, and altered calcium stores.
Conclusions:
- Understanding the diverse causes of excitation-contraction coupling dysfunction is crucial for diagnosing and treating muscle diseases.
- Further research into these pathophysiologic mechanisms can elucidate disease progression and identify therapeutic targets.
Related Concept Videos
01:20Excitation-Contraction Coupling in Skeletal Muscles
16.7K
Excitation-contraction coupling is a series of events that occur between generating an action potential and initiating a muscle contraction. It occurs at the triad, a structure found in skeletal muscle fibers that comprise a T-tubule and terminal cisternae of the sarcoplasmic reticulum on each side. These triads are visible in longitudinally sectioned muscle fibers. They are typically located at the A-I junction — the junction between the A and I bands of the sarcomere.
When an action...
When an action...
16.7K
01:20Motor Unit Stimulation
4.3K
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...
4.3K
01:29Relaxation of Skeletal Muscles
6.4K
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....
6.4K
01:26Cross-bridge Cycle
124.0K
As muscle contracts, the overlap between the thin and thick filaments increases, decreasing the length of the sarcomere—the contractile unit of the muscle—using energy in the form of ATP. At the molecular level, this is a cyclic, multistep process that involves binding and hydrolysis of ATP, and movement of actin by myosin.
124.0K
01:10Muscle Contraction
9.2K
In skeletal muscles, acetylcholine is released by nerve terminals at the motor endplate—the point of synaptic communication between motor neurons and muscle fibers. The binding of acetylcholine to its receptors on the sarcolemma allows entry of sodium ions into the cell and triggers an action potential in the muscle cell. Thus, electrical signals from the brain are transmitted to the muscle. Subsequently, the enzyme acetylcholinesterase breaks down acetylcholine to prevent excessive...
9.2K
01:15Muscle Contraction
98.2K
98.2K