Related Experiment Video

Updated: Jun 8, 2026

Corticospinal Excitability Modulation During Action Observation
12:33

Corticospinal Excitability Modulation During Action Observation

Published on: December 31, 2013

Neuronal mechanism of mirror movements caused by dysfunction of the motor cortex

Fumiharu Tsuboi1, Yukio Nishimura, Kimika Yoshino-Saito

  • 1Department of Developmental Physiology, National Institute for Physiological Sciences, Myodaiji, Okazaki, Aichi, Japan.

The European Journal of Neuroscience
|September 18, 2010
PubMed

Insights

Mirror movements (MMs) in stroke patients may indicate recovery. This study in monkeys suggests MMs result from altered brain signals between motor cortices, not just damage to one side.

Area of Science:

  • Neuroscience
  • Motor Control
  • Neurorehabilitation

Background:

  • Mirror movements (MMs) are involuntary movements in one limb mirroring voluntary movements in the contralateral limb, often seen in hemiplegic stroke patients.
  • The underlying neuronal mechanisms of MMs post-stroke are not fully understood, hindering targeted rehabilitation strategies.

Purpose of the Study:

  • To investigate the neuronal origins of mirror movements following primary motor cortex (M1) dysfunction using an animal model.
  • To elucidate the neural pathways involved in the generation of MMs after stroke-like injury.

Main Methods:

  • Reversible inactivation of the right primary motor cortex (M1) in monkeys using muscimol.
  • Induction and analysis of mirror movements during voluntary grasping tasks.
  • Electromyogram (EMG) recordings to assess muscle activation patterns.
  • Pharmacological blockade of the left M1 to determine its role in MMs.

Main Results:

  • Inactivation of the right M1 induced mirror movements in the right hand during left-hand grasping.
  • Subsequent blockade of the left M1 completely abolished the induced mirror movements.
  • EMG analysis revealed co-activation of homologous muscles in both hands, suggesting bilateral M1 involvement.
  • Findings indicate MMs are driven by enhanced bilateral M1 activation from higher centers and reduced interhemispheric inhibition.

Conclusions:

  • Mirror movements after M1 dysfunction are not solely due to the affected hemisphere's damage.
  • The intact hemisphere's motor cortex plays a crucial role in generating MMs, influenced by descending drives and interhemispheric communication.
  • Understanding these mechanisms can inform neurorehabilitation approaches for post-stroke motor deficits.

More Related Videos

Robotic Mirror Therapy System for Functional Recovery of Hemiplegic Arms10:32

Robotic Mirror Therapy System for Functional Recovery of Hemiplegic Arms

Published on: August 15, 2016

Real-time Video Projection in an MRI for Characterization of Neural Correlates Associated with Mirror Therapy for Phantom Limb Pain11:29

Real-time Video Projection in an MRI for Characterization of Neural Correlates Associated with Mirror Therapy for Phantom Limb Pain

Published on: April 20, 2019

Related Concept Videos

Mechanism of Ciliary Motion01:05

Mechanism of Ciliary Motion

The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
Somatosensation01:33

Somatosensation

The somatosensory system relays sensory information from the skin, mucous membranes, limbs, and joints. Somatosensation is more familiarly known as the sense of touch. A typical somatosensory pathway includes three types of long neurons: primary, secondary, and tertiary. Primary neurons have cell bodies located near the spinal cord in groups of neurons called dorsal root ganglia. The sensory neurons of ganglia innervate designated areas of skin called dermatomes.
Direct Motor Pathways01:11

Direct 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...
Motor and Sensory Areas of the Cortex01:14

Motor 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.
Somatosensory, Motor, and Association Cortex01:23

Somatosensory, Motor, and Association Cortex

The somatosensory cortex in the parietal lobes is crucial for interpreting sensory data such as touch, temperature, and proprioception. The somatosensory cortex, situated in the parietal lobes, plays a vital role in interpreting sensory information like touch, temperature, and proprioception—awareness of body position. This specialized brain region features an organized structure wherein neurons at the top primarily process sensations originating from the lower body. In contrast, those at the...
Alterations in Muscle Tone ll01:12

Alterations in Muscle Tone ll

Alterations in muscle tone are common manifestations of neurological disorders and reflect dysfunction within different nervous system regions. Spasticity, paratonia, and dystonia represent distinct forms of hypertonia, each with unique mechanisms, clinical features, and diagnostic importance.CharacteristicsSpasticity happens from upper motor neuron lesions and is characterized by velocity-dependent resistance to passive movement. Clinical features include:Exaggerated deep tendon reflexesClonus...