The motor cortical areas

2020 ◽  
pp. 464-467
Author(s):  
Edmund T. Rolls
Keyword(s):  
Motor Cortex ◽  
Parietal Cortex ◽  
Mirror Neurons ◽  
Cortical Areas ◽  
Motor Cortical ◽  
Premotor Areas

Premotor cortical areas have outputs to the motor cortex, and receive inputs from the parietal cortex to implement actions such as reaching into space and grasping objects. Neurons in some premotor areas respond not only to movements being performed, but also to the sight of movements being performed, and are termed ‘mirror neurons’.

scholarly journals Motor cortical inactivation reduces the gain of kinematic primitives in mice performing a hold-still center-out reach task

2018 ◽  
Author(s):  
Tejapratap Bollu ◽  
Samuel C. Whitehead ◽  
Nikil Prasad ◽  
Jackson Walker ◽  
Nitin Shyamkumar ◽  
...  
Keyword(s):  
Motor Cortex ◽  
High Precision ◽  
Closed Loop ◽  
Building Blocks ◽  
Kinematic Parameter ◽  
Cortical Areas ◽  
Freely Moving ◽  
Motor Cortical ◽  
Peak Speed ◽  
Contralateral Motor

SUMMARYMotor sequences are constructed from primitives, hypothesized building blocks of movement, but mechanisms of primitive generation remain unclear. Using automated homecage training and a novel forelimb sensor, we trained freely-moving mice to initiate forelimb sequences with clearly resolved submillimeter-scale micromovements followed by millimeter-scale reaches to learned spatial targets. Hundreds of thousands of trajectories were decomposed into millions of kinematic primitives, while closed-loop photoinhibition was used to test roles of motor cortical areas. Inactivation of contralateral motor cortex reduced primitive peak speed but, surprisingly, did not substantially affect primitive direction, initiation, termination, or complexity, resulting in isomorphic, spatially contracted trajectories that undershot targets. Our findings demonstrate separable loss of a single kinematic parameter, speed, and identify conditions where loss of cortical drive reduces the gain of motor primitives but does not affect their generation, timing or direction. The combination of high precision forelimb sensing with automated training and neural manipulation provides a system for studying how motor sequences are constructed from elemental building blocks.

Focal Photothrombotic Lesion of the Rat Motor Cortex Increases BDNF Levels in Motor-Sensory Cortical Areas Not Accompanied by Recovery of Forelimb Motor Skills

2007 ◽  
Vol 24 (8) ◽  
pp. 1362-1377 ◽  
Author(s):  
Dorota Sulejczak ◽  
Ewelina Ziemlińska ◽  
Julita Czarkowska-Bauch ◽  
Ewa Nosecka ◽  
Ryszard Strzalkowski ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Motor Skills ◽  
Cortical Areas

scholarly journals Distinct roles for motor cortical and thalamic inputs to striatum during motor learning and execution

2019 ◽  
Author(s):  
Steffen B. E. Wolff ◽  
Raymond Ko ◽  
Bence P. Ölveczky
Keyword(s):  
Motor Cortex ◽  
Motor Learning ◽  
Learning Process ◽  
Brain Areas ◽  
Thalamic Neurons ◽  
Cortical Input ◽  
Motor Circuits ◽  
Motor Network ◽  
Motor Cortical ◽  
Cortical Inputs

AbstractThe acquisition and execution of learned motor sequences are mediated by a distributed motor network, spanning cortical and subcortical brain areas. The sensorimotor striatum is an important cog in this network, yet how its two main inputs, from motor cortex and thalamus respectively, contribute to its role in motor learning and execution remains largely unknown. To address this, we trained rats in a task that produces highly stereotyped and idiosyncratic motor sequences. We found that motor cortical input to the sensorimotor striatum is critical for the learning process, but after the behaviors were consolidated, this corticostriatal pathway became dispensable. Functional silencing of striatal-projecting thalamic neurons, however, disrupted the execution of the learned motor sequences, causing rats to revert to behaviors produced early in learning and preventing them from re-learning the task. These results show that the sensorimotor striatum is a conduit through which motor cortical inputs can drive experience-dependent changes in subcortical motor circuits, likely at thalamostriatal synapses.

scholarly journals Somatosensory cortical excitability changes precede those in motor cortex during human motor learning

2019 ◽  
Vol 122 (4) ◽  
pp. 1397-1405 ◽  
Author(s):  
Hiroki Ohashi ◽  
Paul L. Gribble ◽  
David J. Ostry
Keyword(s):  
Motor Cortex ◽  
Motor Learning ◽  
Evoked Potentials ◽  
Somatosensory Cortex ◽  
Somatosensory Evoked Potentials ◽  
Motor Skill ◽  
Cortical Excitability ◽  
Motor Evoked Potentials ◽  
Human Motor ◽  
Motor Cortical

Motor learning is associated with plasticity in both motor and somatosensory cortex. It is known from animal studies that tetanic stimulation to each of these areas individually induces long-term potentiation in its counterpart. In this context it is possible that changes in motor cortex contribute to somatosensory change and that changes in somatosensory cortex are involved in changes in motor areas of the brain. It is also possible that learning-related plasticity occurs in these areas independently. To better understand the relative contribution to human motor learning of motor cortical and somatosensory plasticity, we assessed the time course of changes in primary somatosensory and motor cortex excitability during motor skill learning. Learning was assessed using a force production task in which a target force profile varied from one trial to the next. The excitability of primary somatosensory cortex was measured using somatosensory evoked potentials in response to median nerve stimulation. The excitability of primary motor cortex was measured using motor evoked potentials elicited by single-pulse transcranial magnetic stimulation. These two measures were interleaved with blocks of motor learning trials. We found that the earliest changes in cortical excitability during learning occurred in somatosensory cortical responses, and these changes preceded changes in motor cortical excitability. Changes in somatosensory evoked potentials were correlated with behavioral measures of learning. Changes in motor evoked potentials were not. These findings indicate that plasticity in somatosensory cortex occurs as a part of the earliest stages of motor learning, before changes in motor cortex are observed. NEW & NOTEWORTHY We tracked somatosensory and motor cortical excitability during motor skill acquisition. Changes in both motor cortical and somatosensory excitability were observed during learning; however, the earliest changes were in somatosensory cortex, not motor cortex. Moreover, the earliest changes in somatosensory cortical excitability predict the extent of subsequent learning; those in motor cortex do not. This is consistent with the idea that plasticity in somatosensory cortex coincides with the earliest stages of human motor learning.

scholarly journals Electrical microstimulation evokes saccades in posterior parietal cortex of common marmosets

2019 ◽  
Vol 122 (4) ◽  
pp. 1765-1776 ◽  
Author(s):  
Maryam Ghahremani ◽  
Kevin D. Johnston ◽  
Liya Ma ◽  
Lauren K. Hayrynen ◽  
Stefan Everling
Keyword(s):  
Eye Movements ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Common Marmoset ◽  
Primate Species ◽  
Oculomotor Control ◽  
Electrical Microstimulation ◽  
Cortical Areas ◽  
Posterior Parietal ◽  
The Common

The common marmoset ( Callithrix jacchus) is a small-bodied New World primate increasing in prominence as a model animal for neuroscience research. The lissencephalic cortex of this primate species provides substantial advantages for the application of electrophysiological techniques such as high-density and laminar recordings, which have the capacity to advance our understanding of local and laminar cortical circuits and their roles in cognitive and motor functions. This is particularly the case with respect to the oculomotor system, as critical cortical areas of this network such as the frontal eye fields (FEF) and lateral intraparietal area (LIP) lie deep within sulci in macaques. Studies of cytoarchitecture and connectivity have established putative homologies between cortical oculomotor fields in marmoset and macaque, but physiological investigations of these areas, particularly in awake marmosets, have yet to be carried out. Here we addressed this gap by probing the function of posterior parietal cortex of the common marmoset with electrical microstimulation. We implanted two animals with 32-channel Utah arrays at the location of the putative area LIP and applied microstimulation while they viewed a video display and made untrained eye movements. Similar to previous studies in macaques, stimulation evoked fixed-vector and goal-directed saccades, staircase saccades, and eyeblinks. These data demonstrate that area LIP of the marmoset plays a role in the regulation of eye movements, provide additional evidence that this area is homologous with that of the macaque, and further establish the marmoset as a valuable model for neurophysiological investigations of oculomotor and cognitive control. NEW & NOTEWORTHY The macaque monkey has been the preeminent model for investigations of oculomotor control, but studies of cortical areas are limited, as many of these areas are buried within sulci in this species. Here we applied electrical microstimulation to the putative area LIP of the lissencephalic cortex of awake marmosets. Similar to the macaque, microstimulation evoked contralateral saccades from this area, supporting the marmoset as a valuable model for studies of oculomotor control.

Movement- and task-related activations of motor cortical areas: A positron emission tomographic study

1994 ◽  
Vol 36 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Philippe Remy ◽  
Monica Zilbovicius ◽  
Anne Leroy-Willig ◽  
Andr� Syrota ◽  
Yves Samson
Keyword(s):  
Positron Emission Tomographic ◽  
Cortical Areas ◽  
Positron Emission ◽  
Motor Cortical ◽  
And Task
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