motor cortex


Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
Related to motor cortex: sensory cortex, supplementary motor cortex

mo·tor cor·tex

the region of the cerebral cortex most nearly immediately influencing movements of the face, neck and trunk, and upper and lower extremities; it corresponds approximately to Brodmann areas 4 and 6 of the precentral gyrus and anterior paracentral gyrus, and immediately adjacent portions of the superior and middle frontal gyri; its effects on the motor neurons innervating the skeletal musculature are mediated by corticospinal fibers (pyramidal tract) and corticonuclear fibers and are particularly essential for the human capacity to perform finely graded movements of the extremities, especially the upper.

mo·tor cor·tex

(mō'tŏr kōr'teks)
The region of the cerebral cortex most immediately influencing movements of the face, neck, trunk, arms, and legs; its effects on the motor neurons innervating the skeletal musculature are mediated by the pyramidal tract.
Synonym(s): excitable area, motor area, Rolando area.

motor cortex

The part of the surface layer of each hemisphere of the main brain (cerebrum) in which voluntary movement is initiated. These areas can be mapped out to show which parts of them are responsible for movement of any particular parts of the body. The map resembles a distorted and inverted human figure.

motor cortex

the part of the cerebral cortex of the brain that controls the motor functions.

Rolando,

Luigi, Italian anatomist, 1773-1831.
fissure of Rolando - a double S-shaped fissure extending obliquely upward and backward on the lateral surface of each cerebral hemisphere at the boundary between frontal and parietal lobes. Synonym(s): central sulcus
rolandic epilepsy - a benign autosomal dominant form of epilepsy occurring in children.
Rolando angle - the angle at which the fissure of Rolando meets with the midplane.
Rolando area - the region of the cerebral cortex most immediately influencing movements of the face, neck and trunk, arm, and leg. Synonym(s): motor cortex
Rolando cells - the nerve cells in Rolando gelatinous substance of the spinal cord.
Rolando column - a slight ridge on either side of the medulla oblongata related to the descending trigeminal tract and nucleus.
Rolando gelatinous substance - the apical part of the posterior horn of the spinal cord's gray matter, composed largely of very small nerve cells. Synonym(s): gelatinous substance
Rolando tubercle - a longitudinal prominence on the dorsolateral surface of the medulla oblongata along the lateral border of the tuberculum cuneatum. Synonym(s): tuberculum cinereum

cortex, motor 

Area of the frontal lobe of the brain just anterior to the central sulcus which is responsible for voluntary movements of the eyes (as well as other voluntary movements of other parts of the body). The motor cortex in each hemisphere controls mainly muscles on the opposite side of the body. It is laid out according to the parts of the body, with the region controlling the feet at the top and the region controlling the legs, the trunk, the arms and the head in descending order.
References in periodicals archive ?
The resting motor threshold (rMT) was determined before each session using single-pulse stimulation over the left primary motor cortex.
If the arm-hand region of motor cortex is often spared in MCA stroke, this might provide an opportunity for use of cortically driven neural prostheses in patients with severe paresis, assuming that apparent sparing on structural imaging studies corresponds to substantial sparing at the neuronal level.
There were tau-positive neurons and tufted astrocytes in frontal, temporal, parietal, and motor cortex (Figure 12, E; positive with Gallyas stain in Figure 12, E, inset), nucleus basalis, caudate, putamen (Figure 12, F), globus pallidus, thalamus, subthalamic nucleus (Figure 12, G), and many brainstem nuclei.
The motor cortex was identified clinically by evaluating the surface markings of the brain.
STN receives direct excitatory glutamatergic afferent from frontal cortex and exerts an excitatory drive to GPi/SNr, and then exerts a strong inhibitive feedback to the motor cortex excitability through the relay of thalamus (Plenz and Kital, 1999).
epidural stimulation of the motor cortex, transcranial direct current stimulation, transcranial magnetic stimulation).
One second after rinsing, the researchers applied transcranial magnetic stimulation to the participants' scalps to detect activity in the motor cortex.
The hindlimb hemiparesis induced by unilateral motor cortex lesion shows complete recovery at 10 days with least variability among rats after infarction (4,5).
TMS can be used to map cortical representations of the brain by stimulating the motor cortex with an electromagnetic coil placed over the skull and measuring the resultant electromyographic (EMG) activity in the target muscle (Taylor et al 2008).
It is thought to interrupt neuronal excitability in the motor cortex of the brain, which has been implicated as a trigger in the cascade of migraine events.
The CI therapy group exhibited profuse increases in grey matter in primary sensory and motor cortex, premotor cortex, supplementary motor cortex, and the hippocampus.
For example, a preliminary report showed in serial functional neuroimaging that improvements in precision of a grip task on WMFT were accompanied by a reduction in contralesional activation with more focused activity towards ipsilesional primary motor cortex M1 (Dong et al 2006).