Using a classic paper by Evarts as a platform for discussing cortical control of skeletal muscle in awake, behaving primates

2012 ◽  
Vol 36 (4) ◽  
pp. 246-250
Author(s):  
Aaron L. Cecala
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Mammalian Species ◽  
Model Organisms ◽  
Precentral Gyrus ◽  
Physiological Mechanisms ◽  
Ethical Implications ◽  
Scientific Investigations ◽  
Neurophysiological Data

A growing portion of premedical curricula is being devoted to the study of physiological mechanisms underlying animal behavior. In the present article, I describe an activity centered around a classic Journal of Neurophysiology paper by Edward V. Evarts that lays the foundation for students to investigate common behavioral and physiological techniques used to study motor control in primates. Students will leave this activity being able to 1) critically assess behavioral, electromyographic, and single unit (extracellular) neurophysiological data typically acquired by behavioral neurophysiologists; 2) provide physiological evidence that the primate precentral gyrus (primary motor cortex) controls voluntary movements of the wrist; 3) intelligently discuss hypotheses concerning the role of the primary motor cortex in the generation of movement in mammalian species; and 4) discuss the ethical implications of using mammalian species as model organisms. The skills and background knowledge gained in this activity lay the platform for advanced study of scientific investigations into sensory, motor, and cognitive processes in undergraduate, graduate, or medical school curricula.

scholarly journals Role of cutaneous and proprioceptive inputs in sensorimotor integration and plasticity occurring in the facial primary motor cortex

2020 ◽  
Vol 598 (4) ◽  
pp. 839-851 ◽  
Author(s):  
Giovanna Pilurzi ◽  
Francesca Ginatempo ◽  
Beniamina Mercante ◽  
Luigi Cattaneo ◽  
Giovanni Pavesi ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Sensorimotor Integration ◽  
Primary Motor Cortex ◽  
Proprioceptive Inputs

Role of Voluntary Drive in Encoding an Elementary Motor Memory

2005 ◽  
Vol 93 (2) ◽  
pp. 1099-1103 ◽  
Author(s):  
Alain Kaelin-Lang ◽  
Lumy Sawaki ◽  
Leonardo G. Cohen
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Motor Memory ◽  
Motor Drive ◽  
Motor Training ◽  
Corticomotor Excitability ◽  
Proprioceptive Input ◽  
Active Training ◽  
Passive Movements

Motor training consisting of repetitive thumb movements results in encoding of motor memories in the primary motor cortex. It is not known if proprioceptive input originating in the training movements is sufficient to produce this effect. In this study, we compared the ability of training consisting of voluntary (active) and passively-elicited (passive) movements to induce this form of plasticity. Active training led to successful encoding accompanied by characteristic changes in corticomotor excitability, while passive training did not. These results support a pivotal role for voluntary motor drive in coding motor memories in the primary motor cortex.

scholarly journals The Role of Human Primary Motor Cortex in the Production of Skilled Finger Sequences

2018 ◽  
Vol 38 (6) ◽  
pp. 1430-1442 ◽  
Author(s):  
Atsushi Yokoi ◽  
Spencer A. Arbuckle ◽  
Jörn Diedrichsen
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex

scholarly journals Dexterous Object Manipulation Requires Context-Dependent Sensorimotor Cortical Interactions in Humans

2019 ◽  
Vol 30 (5) ◽  
pp. 3087-3101 ◽  
Author(s):  
Pranav J Parikh ◽  
Justin M Fine ◽  
Marco Santello
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Object Manipulation ◽  
Storage And Retrieval ◽  
Relative Contribution ◽  
Contact Points ◽  
Behavioral Studies ◽  
Online Feedback ◽  
Digit Position

Abstract Dexterous object manipulation is a hallmark of human evolution and a critical skill for everyday activities. A previous work has used a grasping context that predominantly elicits memory-based control of digit forces by constraining where the object should be grasped. For this “constrained” grasping context, the primary motor cortex (M1) is involved in storage and retrieval of digit forces used in previous manipulations. In contrast, when choice of digit contact points is allowed (“unconstrained” grasping), behavioral studies revealed that forces are adjusted, on a trial-to-trial basis, as a function of digit position. This suggests a role of online feedback of digit position for force control. However, despite the ubiquitous nature of unconstrained hand–object interactions in activities of daily living, the underlying neural mechanisms are unknown. Using noninvasive brain stimulation, we found the role of primary motor cortex (M1) and somatosensory cortex (S1) to be sensitive to grasping context. In constrained grasping, M1 but not S1 is involved in storing and retrieving learned digit forces and position. In contrast, in unconstrained grasping, M1 and S1 are involved in modulating digit forces to position. Our findings suggest that the relative contribution of memory and online feedback modulates sensorimotor cortical interactions for dexterous manipulation.

Interhemispheric Inhibition in Distal and Proximal Arm Representations in the Primary Motor Cortex

2007 ◽  
Vol 97 (3) ◽  
pp. 2511-2515 ◽  
Author(s):  
Michelle L. Harris-Love ◽  
Monica A. Perez ◽  
Robert Chen ◽  
Leonardo G. Cohen
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Biceps Brachii ◽  
Conditioning Stimulus ◽  
Motor Evoked Potential ◽  
Triceps Brachii ◽  
Functional Movement ◽  
Resting Motor Threshold ◽  
Inhibitory Interactions

Interhemispheric inhibitory interactions (IHI) operate between homologous distal hand representations in primary motor cortex (M1). It is not known whether proximal arm representations exhibit comparable effects on their homologous counterparts. We studied IHI in different arm representations, targeting triceps brachii (TB, n = 13), first dorsal interosseous (FDI, n = 13), and biceps brachii (BB, n = 7) muscles in healthy volunteers. Transcranial magnetic stimulation test stimuli (TS) were delivered to M1 contralateral to the target muscle preceded 10 ms by a conditioning stimulus (CS) to the opposite M1 at 110–150% resting motor threshold (RMT). IHI was calculated as the ratio between motor-evoked potential (MEP) amplitudes in conditioned relative to unconditioned trials. Mean RMTs were 38.9, 46.9, and 46.0% of stimulator output in FDI, TB, and BB muscles, respectively. IHI was 0.45 ± 0.41 (FDI), 0.78 ± 0.38 (TB), and 0.52 ± 0.32 (BB, P < 0.01) when test MEP amplitudes were matched and 0.28 ± 0.17 (FDI) and 0.85 ± 0.31 (TB, P < 0.05) when TS intensities expressed as percentage RMT were matched. Significant IHI ( P < 0.05) was identified with minimal CS intensities (expressed as percentage stimulator output) in the 30 s for FDI, 60 s for TB, and 40 s for BB. Additionally, a CS of roughly 120% RMT suppressed the test MEP but not a test H-reflex in BB, suggesting IHI observed in BB is likely mediated by a supraspinal mechanism. We conclude that IHI differs between different arm muscle representations, comparable between BB and FDI but lesser for TB. This finding suggests the amount of IHI between different arm representations does not strictly follow a proximal-to-distal gradient, but may be related to the role of each muscle in functional movement synergies.

scholarly journals The Role of Primary Motor Cortex (M1) Glutamate and GABA Signaling in L-DOPA-Induced Dyskinesia in Parkinsonian Rats

2016 ◽  
Vol 36 (38) ◽  
pp. 9873-9887 ◽  
Author(s):  
D. Lindenbach ◽  
M. M. Conti ◽  
C. Y. Ostock ◽  
J. A. George ◽  
A. A. Goldenberg ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Gaba Signaling

Gross Total Resection of a Grade IV Astrocytoma Adjacent to the Precentral Gyrus With Nonawake Motor Mapping and Motor-Evoked Potential Monitoring: 3-Dimensional Operative Video

2019 ◽  
Author(s):  
Burak Ozaydin ◽  
Ihsan Dogan ◽  
Bryan J Wheeler ◽  
Mustafa K Baskaya
Keyword(s):  
Motor Cortex ◽  
Evoked Potential ◽  
Primary Motor Cortex ◽  
Motor Evoked Potential ◽  
Gross Total Resection ◽  
Precentral Gyrus ◽  
Total Resection ◽  
Motor Mapping ◽  
3 Dimensional ◽  
Intraoperative Adjuncts

Abstract Surgical treatment of the gliomas located in or adjacent to the eloquent areas poses significant challenge to neurosurgeons. The main goal of the surgery is to achieve maximal safe resection while preserving the neurological function. This might be possible with utilizing pre- and intraoperative adjuncts such as functional magnetic resonance imaging (MRI), image guidance, mapping of the function of interest, intraoperative MRI, and neurophysiological monitoring. In this video, we demonstrate the utilization of nonawake mapping and motor-evoked potential (MEP) monitoring for the resection of a right-sided posterior superior frontal gyrus grade IV astrocytoma adjacent to the primary motor cortex. The patient is a 69-yr-old woman presented with multiple episodes of simple partial seizures involving her left leg and spreading to the left arm. MRI and functional MRI examinations showed a heterogeneously enhancing mass with peritumoral edema adjacent to the primary motor cortex. Because the patient did not want to undergo an awake craniotomy, a decision was made to perform the resection of the tumor with nonawake motor mapping and continuous MEP monitoring. Nonawake motor mapping and MEP monitoring enabled us to perform gross total resection. Because it has been shown that supratotal resection may provide improved survival outcome,1,2 we extended the white matter resection beyond the contrast enhancing area in noneloquent parts of the tumor. Surgical steps in dealing with vascular anatomy as well as utilizing intraoperative adjuncts such as motor mapping and MEP monitoring to enhance the extent of resection while preserving the function are demonstrated in this 3-dimensional surgical video.  The patient consented to publication of her operative video.

P57 Investigating the Role of the Primary Motor Cortex in Upper Limb Freezing

2020 ◽  
Vol 131 (4) ◽  
pp. e207
Author(s):  
M. Topka ◽  
M. Scholten ◽  
C. Zrenner ◽  
P. Belardinelli ◽  
U. Ziemann ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Upper Limb ◽  
Primary Motor Cortex
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