Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Motor Unit Stimulation01:20

Motor Unit Stimulation

3.4K
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...
3.4K
Muscle Stimulation Frequency01:22

Muscle Stimulation Frequency

4.2K
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...
4.2K
Motor Units01:13

Motor Units

7.3K
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...
7.3K
Hierarchy of Motor Control01:18

Hierarchy of Motor Control

5.7K
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.
5.7K
Direct Motor Pathways01:11

Direct Motor Pathways

4.0K
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...
4.0K
Indirect Motor Pathways01:22

Indirect Motor Pathways

2.9K
The indirect motor or extrapyramidal pathways originate in the brainstem, the lower portion of the brain that connects it to the spinal cord. They consist of several distinct tracts, each with specialized functions. The four main tracts of the indirect motor pathways are the vestibulospinal tract, the reticulospinal tract, the tectospinal tract, and the rubrospinal tract.
The vestibulospinal tract originates in the vestibular nuclei of the brainstem. The vestibular system detects changes in...
2.9K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Phase-specific premotor inhibition modulates leech rhythmic motor output.

eLife·2026
Same author

Transgenesis enables mapping of segmental ganglia in the leech Helobdella austinensis.

The Journal of experimental biology·2024
Same author

Motor neural networks in the leech.

Trends in neurosciences·2023
Same author

Peripersonal encoding of forelimb proprioception in the mouse somatosensory cortex.

Nature communications·2023
Same author

Intersegmental Interactions Give Rise to a Global Network.

Frontiers in neural circuits·2022
Same author

A tale of two leeches: Toward the understanding of the evolution and development of behavioral neural circuits.

Evolution & development·2020
Same journal

A Matter of Parameters: Tailored Transcranial Focused Ultrasound Enhances Cortico-Thalamo-Cortical Circuit Resonance.

The Journal of neuroscience : the official journal of the Society for Neuroscience·2026
Same journal

Proactive visual and motor prioritization differentially scale with cue reliability.

The Journal of neuroscience : the official journal of the Society for Neuroscience·2026
Same journal

Erratum: Yao et al., "Estrogen Regulates Bcl-w and Bim Expression: Role in Protection against β-Amyloid Peptide-Induced Neuronal Death".

The Journal of neuroscience : the official journal of the Society for Neuroscience·2026
Same journal

Erratum: L'Episcopo et al., "Plasticity of Subventricular Zone Neuroprogenitors in MPTP (1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine) Mouse Model of Parkinson's Disease Involves Cross Talk between Inflammatory and Wnt/β-Catenin Signaling Pathways: Functional Consequences for Neuroprotection and Repair".

The Journal of neuroscience : the official journal of the Society for Neuroscience·2026
Same journal

Representations of subsecond duration-based timing by complex spike synchrony in cerebellar Purkinje neurons.

The Journal of neuroscience : the official journal of the Society for Neuroscience·2026
Same journal

The extended language network: Language-responsive brain areas whose contributions to language remain to be discovered.

The Journal of neuroscience : the official journal of the Society for Neuroscience·2026
See all related articles

Related Experiment Video

Updated: Dec 30, 2025

The Swimmeret System of Crayfish: A Practical Guide for the Dissection of the Nerve Cord and Extracellular Recordings of the Motor Pattern
11:45

The Swimmeret System of Crayfish: A Practical Guide for the Dissection of the Nerve Cord and Extracellular Recordings of the Motor Pattern

Published on: November 25, 2014

12.6K

Phase-Specific Motor Efference during a Rhythmic Motor Pattern.

Ignacio Alonso1, Agustín Sanchez Merlinsky1, Lidia Szczupak2

  • 1Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Fisiología, Biología Molecular y Neurociencias, Ciudad Universitaria, (C1428EHA) Buenos Aires, Argentina.

The Journal of Neuroscience : the Official Journal of the Society for Neuroscience
|January 26, 2020
PubMed
Summary
This summary is machine-generated.

Leech crawling involves a motor control mechanism called corollary discharge, which specifically inhibits self-generated sensory signals. This study shows that touch (T) neurons, unlike pressure (P) neurons, are inhibited during leech skin contraction, preventing motor pattern disruption.

Keywords:
corollary dischargeleechmechanosensoryrhythmic motor behaviour

More Related Videos

Functional Isolation of Single Motor Units of Rat Medial Gastrocnemius Muscle
06:54

Functional Isolation of Single Motor Units of Rat Medial Gastrocnemius Muscle

Published on: December 26, 2020

5.7K
Extracellularly Identifying Motor Neurons for a Muscle Motor Pool in Aplysia californica
13:37

Extracellularly Identifying Motor Neurons for a Muscle Motor Pool in Aplysia californica

Published on: March 25, 2013

12.1K

Related Experiment Videos

Last Updated: Dec 30, 2025

The Swimmeret System of Crayfish: A Practical Guide for the Dissection of the Nerve Cord and Extracellular Recordings of the Motor Pattern
11:45

The Swimmeret System of Crayfish: A Practical Guide for the Dissection of the Nerve Cord and Extracellular Recordings of the Motor Pattern

Published on: November 25, 2014

12.6K
Functional Isolation of Single Motor Units of Rat Medial Gastrocnemius Muscle
06:54

Functional Isolation of Single Motor Units of Rat Medial Gastrocnemius Muscle

Published on: December 26, 2020

5.7K
Extracellularly Identifying Motor Neurons for a Muscle Motor Pool in Aplysia californica
13:37

Extracellularly Identifying Motor Neurons for a Muscle Motor Pool in Aplysia californica

Published on: March 25, 2013

12.1K

Area of Science:

  • Neuroscience
  • Motor Control
  • Sensory Processing

Background:

  • Motor behaviors require inhibition of self-generated sensory signals, a process known as corollary discharge.
  • In leeches, T (touch) and P (pressure) mechanosensory neurons detect skin stimuli.
  • Leech locomotion involves rhythmic elongation and contraction phases.

Purpose of the Study:

  • To investigate the specificity and function of corollary discharge in leech motor control.
  • To determine if sensory neurons are differentially affected by motor commands during crawling.
  • To understand how self-generated sensory input is managed during leech locomotion.

Main Methods:

  • Electrophysiological recordings in isolated leech ganglia.
  • Induction of fictive crawling using dopamine.
  • Analysis of mechanosensory neuron activity (T and P cells) during simulated crawling phases.

Main Results:

  • T cells, but not P cells, exhibited phase-dependent inhibitory postsynaptic potentials (IPSPs) during the contraction phase of fictive crawling.
  • The timing and magnitude of T-cell IPSPs correlated with motoneuron activity during contraction.
  • Excitation of T cells during contraction disrupted the rhythmic motor pattern, indicating behavioral relevance.

Conclusions:

  • The central crawling network sends behaviorally relevant, target-specific (T vs. P neurons) and phase-specific (contraction vs. elongation) corollary discharge signals.
  • This specific inhibition prevents self-generated sensory input from perturbing motor control during leech locomotion.
  • Corollary discharge is a conserved mechanism for optimizing motor behavior by managing reafferent sensory information.