Effect of age on changes in motor units functional connectivity
Summary
Aging increases motor unit dependency in the biceps brachii muscle. This study found higher normalized mutual information (NMI) in older adults, indicating greater reliance on remaining motor units.
Area of Science:
- Neuromuscular physiology
- Aging and motor control
Background:
- Muscle strength declines with age due to changes in motor unit functional connectivity.
- Motor unit recruitment patterns are altered in older adults.
Purpose of the Study:
- To investigate the effect of age on motor unit recruitment in the biceps brachii muscle.
- To quantify changes in motor unit dependency using surface electromyogram (sEMG) signals.
Main Methods:
- Recorded two-channel sEMG from the biceps brachii during maximal isometric contraction in young (20-35 years) and old (60-70 years) healthy adults.
- Calculated normalized mutual information (NMI) as a measure of motor unit dependency.
- Performed statistical analysis to compare NMI between age groups.
Main Results:
- Older adults exhibited significantly higher NMI compared to young adults.
- This suggests an increased dependency among remaining motor units in the elderly.
Conclusions:
- Age-related changes in motor unit functional connectivity lead to increased dependency.
- Reduced motor unit number with aging may necessitate greater recruitment of remaining units, impacting muscle strength.
More Related Videos
06:08Author Spotlight: Studying Neuromuscular Responses and Motor Neuron Plasticity in Neurodegenerative Diseases
Published on: April 19, 2024
882
12:18The Neuromuscular Junction: Measuring Synapse Size, Fragmentation and Changes in Synaptic Protein Density Using Confocal Fluorescence Microscopy
Published on: December 26, 2014
22.9K
Related Concept Videos
01:13Motor Units
9.9K
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...
9.9K
00:46Motor Units
62.9K
A motor unit consists of two main components: a single efferent motor neuron (i.e., a neuron that carries impulses away from the central nervous system) and all of the muscle fibers it innervates. The motor neuron may innervate multiple muscle fibers, which are single cells, but only one motor neuron innervates a single muscle fiber.
62.9K
01:27Pharmacodynamics in Geriatric Patients: Effects of Age
315
Age-related pharmacokinetic changes are extensively documented, but understanding age-related pharmacodynamic alterations is relatively limited. This knowledge gap can be partly attributed to the complexity of developing appropriate measures of drug responses compared to bioanalytical methods for determining drug concentrations.Most information regarding age-related differences in human pharmacodynamics originates from cross-sectional studies. However, these studies assume that observed mean...
315
01:19The Effect of Aging on Tissues
4.1K
Several body functions deteriorate with age. The external signs of aging are easily identifiable. For example, the skin becomes dry, less elastic, and thins out, forming wrinkles. The skin of the face begins to appear looser due to a decrease in the levels of elastic and collagen fibers in the connective tissue. Additionally, melanin production in the hair follicle decreases with age, resulting in gray hair. Moreover, the senses of sight and hearing decline, so glasses and hearing aids may...
4.1K