Related Experiment Video
Updated: Jul 14, 2026
07:52
In Vivo Wireless Optogenetic Control of Skilled Motor Behavior
Published on: November 22, 2021
Functional anatomy of motor urgency
Stéphane Thobois1, Bénédicte Ballanger, Pierre Baraduc
1Université Lyon I, Hospices Civils de Lyon, Hôpital Neurologique et Neurochirurgical Pierre Wertheimer, Neurologie C, Lyon, France. stephane.thobois@chu-lyon.fr
Neuroimage
|June 8, 2007
Summary
Urgency enhances motor speed by engaging the cerebellum and sensorimotor cortex (SMC). Different motor control strategies involve distinct neural pathways, including corticospinal tracts, during volitional and externally-cued movements.
Area of Science:
- Neuroscience
- Motor Control
- Cognitive Neuroscience
Background:
- Urgency is known to increase movement speed.
- The neural mechanisms underlying this unconscious motor speed-up remain incompletely understood.
- Understanding these mechanisms is crucial for motor control and rehabilitation.
Purpose of the Study:
- To investigate the neural basis of unconscious motor speed-up during urgency.
- To differentiate brain activation patterns associated with self-initiated, externally-cued, and temporally-pressing movements.
- To explore the role of different corticospinal tracts in motor control strategies.
Main Methods:
- Positron Emission Tomography (PET) with H(2)(15)O was used.
- A reaching task was employed with three conditions: self-initiated, externally-cued, and temporally-pressing.
- Brain activity was analyzed comparing different task conditions.
Main Results:
- Urgent responses activated the left parasagittal and lateral cerebellar hemisphere and bilateral sensorimotor cortex (SMC).
- Externally-driven responses recruited contralateral SMC executive areas.
- Volitional responses involved prefrontal cortical areas.
Conclusions:
- Neuromuscular energy thresholds are modulated by task demands.
- The nervous system recruits specific motor pathways (lateral and anterior corticospinal tracts) based on task difficulty and urgency.
- These recruitment strategies resemble those observed in brain injury recovery.
Related Concept Videos
01:13Motor Units
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...
00:46Motor Units
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.
01:18Hierarchy of Motor Control
The hierarchy of motor control refers to the different levels of organization and processing involved in controlling movement in the body. These levels range from higher cortical areas involved in planning and decision-making to lower spinal cord reflexes that respond automatically to external stimuli.
01:11Direct Motor Pathways
The direct motor pathways, also known as the pyramidal tracts, are a group of neural pathways that originate in the brain and descend through the spinal cord. They control the voluntary movement of the body. There are two major direct motor pathways: the corticospinal and the corticobulbar tracts.
The corticospinal tract is responsible for the voluntary movement of the limbs and trunk. It originates in the cerebral cortex of the brain and descends through the cerebrum's internal capsule and the...
The corticospinal tract is responsible for the voluntary movement of the limbs and trunk. It originates in the cerebral cortex of the brain and descends through the cerebrum's internal capsule and the...
01:19The Neuromuscular Junction
The nervous system consists of complex motor neuron circuits, including upper motor neurons originating from the cerebral cortex and lower motor neurons starting in the spinal cord, coordinating both voluntary and involuntary movements. Among these, somatic motor neurons activate skeletal muscles and are classified into alpha, beta, and gamma types. Alpha neurons are vital for voluntary movement coordination, while gamma neurons adjust muscle spindle sensitivity, and the function of beta...
01:14Motor and Sensory Areas of the Cortex
The cerebral cortex, the brain's outermost layer, is pivotal in processing complex cognitive tasks, emotions, and various sensory inputs and executing voluntary motor activities. This intricate structure is divided into three primary functional areas: the motor areas, sensory areas, and association areas.
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex.
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex.