Effect of Forelimb Use on Postnatal Development of the Forelimb Motor Representation in Primary Motor Cortex of the Cat

2005 ◽  
Vol 93 (5) ◽  
pp. 2822-2831 ◽  
Author(s):  
John H. Martin ◽  
Daniel Engber ◽  
Zhuo Meng
Keyword(s):  
Botulinum Toxin ◽  
Motor Cortex ◽  
Postnatal Development ◽  
Primary Motor Cortex ◽  
Botulinum Toxin Injection ◽  
Intracortical Microstimulation ◽  
Behavioral Repertoire ◽  
Concomitant Increase ◽  
Motor Representation ◽  
Forelimb Movements

In the cat, the motor representation in motor cortex develops between wk 8 and wk 13. Motor map development is accompanied by a decrease in the current thresholds for evoking movements with a concomitant increase in the number of effective sites, an increase in the distal representation, and the representation of multijoint synergies. In this study we used intracortical microstimulation in anesthetized cats to examine how forelimb motor experiences influence development of map characteristics. To promote skilled movements during wks 8–13, animals were engaged in daily performance of a prehension task. Forelimb movements were prevented by intramuscular botulinum toxin injection or restraint. To determine whether experience-dependent changes were permanent, we examined the map in different animals between 1 wk and 1 yr after cessation of testing. Promoting forelimb use resulted in an increase in the number of sites from which multiple joint effects were produced by stimulation and the number of joints represented at those sites. The effect was maximal at 1 wk after cessation of testing, and became progressively less at 1 mo and at 4 mo. Preventing limb use resulted in a decreased number of effective sites, an increase in current thresholds for evoking responses, and a decreased representation of joints at multijoint sites. Our findings show that the motor map can respond to novel motor demands as it is forming during development but that it reverts back to one with the properties of a map in a control animal if those demands are not maintained in the animal's behavioral repertoire.

scholarly journals Effective intracortical microstimulation parameters applied to primary motor cortex for evoking forelimb movements to stable spatial end points

2013 ◽  
Vol 110 (5) ◽  
pp. 1180-1189 ◽  
Author(s):  
Gustaf M. Van Acker ◽  
Sommer L. Amundsen ◽  
William G. Messamore ◽  
Hongyu Y. Zhang ◽  
Carl W. Luchies ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Large Scale ◽  
Primary Motor Cortex ◽  
Emg Activity ◽  
Intracortical Microstimulation ◽  
End Points ◽  
End Point ◽  
Motor Effects ◽  
Forelimb Movements ◽  
Stimulation Of

High-frequency, long-duration intracortical microstimulation (HFLD-ICMS) applied to motor cortex is recognized as a useful and informative method for corticomotor mapping by evoking natural-appearing movements of the limb to consistent stable end-point positions. An important feature of these movements is that stimulation of a specific site in motor cortex evokes movement to the same spatial end point regardless of the starting position of the limb. The goal of this study was to delineate effective stimulus parameters for evoking forelimb movements to stable spatial end points from HFLD-ICMS applied to primary motor cortex (M1) in awake monkeys. We investigated stimulation of M1 as combinations of frequency (30–400 Hz), amplitude (30–200 μA), and duration (0.5–2 s) while concurrently recording electromyographic (EMG) activity from 24 forelimb muscles and movement kinematics with a motion capture system. Our results suggest a range of parameters (80–140 Hz, 80–140 μA, and 1,000-ms train duration) that are effective and safe for evoking forelimb translocation with subsequent stabilization at a spatial end point. The mean time for stimulation to elicit successful movement of the forelimb to a stable spatial end point was 475.8 ± 170.9 ms. Median successful frequency and amplitude were 110 Hz and 110 μA, respectively. Attenuated parameters resulted in inconsistent, truncated, or undetectable movements, while intensified parameters yielded no change to movement end points and increased potential for large-scale physiological spread and adverse focal motor effects. Establishing cortical stimulation parameters yielding consistent forelimb movements to stable spatial end points forms the basis for a systematic and comprehensive mapping of M1 in terms of evoked movements and associated muscle synergies. Additionally, the results increase our understanding of how the central nervous system may encode movement.

Organization of the primate face motor cortex as revealed by intracortical microstimulation and electrophysiological identification of afferent inputs and corticobulbar projections

1988 ◽  
Vol 59 (3) ◽  
pp. 796-818 ◽  
Author(s):  
C. S. Huang ◽  
M. A. Sirisko ◽  
H. Hiraba ◽  
G. M. Murray ◽  
B. J. Sessle
Keyword(s):  
Motor Cortex ◽  
Single Neuron ◽  
Primary Motor Cortex ◽  
General Pattern ◽  
Emg Activity ◽  
Projection Neurons ◽  
Intracortical Microstimulation ◽  
Facial Musculature ◽  
The Face ◽  
Afferent Inputs

1. The technique of intracortical microstimulation (ICMS), supplemented by single-neuron recording, was used to carry out an extensive mapping of the face primary motor cortex. The ICMS study involved a total of 969 microelectrode penetrations carried out in 10 unanesthetized monkeys (Macaca fascicularis). 2. Monitoring of ICMS-evoked movements and associated electromyographic (EMG) activity revealed a general pattern of motor cortical organization. This was characterized by a representation of the facial musculature, which partially enclosed and overlapped the rostral, medial, and caudal borders of the more laterally located cortical regions representing the jaw and tongue musculatures. Responses were evoked at ICMS thresholds as low as 1 microA, and the latency of the suprathreshold EMG responses ranged from 10 to 45 ms. 3. Although contralateral movements predominated, a representation of ipsilateral movements was found, which was much more extensive than previously reported and which was intermingled with the contralateral representations in the anterior face motor cortex. 4. In examining the fine organizational pattern of the representations, we found clear evidence for multiple representation of a particular muscle, thus supporting other investigations of the motor cortex, which indicate that multiple, yet discrete, efferent microzones represent an essential organizational principle of the motor cortex. 5. The close interrelationship of the representations of all three muscle groups, as well as the presence of a considerable ipsilateral representation, may allow for the necessary integration of unilateral or bilateral activities of the numerous face, jaw, and tongue muscles, which is a feature of many of the movement patterns in which these various muscles participate. 6. In six of these same animals, plus an additional two animals, single-neuron recordings were made in the motor and adjacent sensory cortices in the anesthetized state. These neurons were electrophysiologically identified as corticobulbar projection neurons or as nonprojection neurons responsive to superficial or deep orofacial afferent inputs. The rostral, medial, lateral, and caudal borders of the face motor cortex were delineated with greater definition by ICMS and these electrophysiological procedures than by cytoarchitectonic features alone. We noted that there was an approximate fit in area 4 between the extent of projection neurons and field potentials anti-dromically evoked from the brain stem and the extent of positive ICMS sites.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Unilateral nasal obstruction affects motor representation development within the face primary motor cortex in growing rats

2017 ◽  
Vol 122 (6) ◽  
pp. 1494-1503 ◽  
Author(s):  
Yasunori Abe ◽  
Chiho Kato ◽  
Karin Harumi Uchima Koecklin ◽  
Hidemasa Okihara ◽  
Takayoshi Ishida ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Nasal Obstruction ◽  
Primary Motor Cortex ◽  
Respiratory Pattern ◽  
Arterial Oxygen ◽  
Electromyographic Activity ◽  
Motor Representation ◽  
Significant Difference ◽  
The Face ◽  
Experimental Group

Postnatal growth is influenced by genetic and environmental factors. Nasal obstruction during growth alters the electromyographic activity of orofacial muscles. The facial primary motor area represents muscles of the tongue and jaw, which are essential in regulating orofacial motor functions, including chewing and jaw opening. This study aimed to evaluate the effect of chronic unilateral nasal obstruction during growth on the motor representations within the face primary motor cortex (M1). Seventy-two 6-day-old male Wistar rats were randomly divided into control ( n = 36) and experimental ( n = 36) groups. Rats in the experimental group underwent unilateral nasal obstruction after cauterization of the external nostril at 8 days of age. Intracortical microstimulation (ICMS) mapping was performed when the rats were 5, 7, 9, and 11 wk old in control and experimental groups ( n = 9 per group per time point). Repeated-measures multivariate ANOVA was used for intergroup and intragroup statistical comparisons. In the control and experimental groups, the total number of positive ICMS sites for the genioglossus and anterior digastric muscles was significantly higher at 5, 7, and 9 wk, but there was no significant difference between 9 and 11 wk of age. Moreover, the total number of positive ICMS sites was significantly smaller in the experimental group than in the control at each age. It is possible that nasal obstruction induced the initial changes in orofacial motor behavior in response to the altered respiratory pattern, which eventually contributed to face-M1 neuroplasticity. NEW & NOTEWORTHY Unilateral nasal obstruction in rats during growth periods induced changes in arterial oxygen saturation (SpO2) and altered development of the motor representation within the face primary cortex. Unilateral nasal obstruction occurring during growth periods may greatly affect not only respiratory function but also craniofacial function in rats. Nasal obstruction should be treated as soon as possible to avoid adverse effects on normal growth, development, and physiological functions.

scholarly journals Anodal tDCS over Primary Motor Cortex Provides No Advantage to Learning Motor Sequences via Observation

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Dace Apšvalka ◽  
Richard Ramsey ◽  
Emily S. Cross
Keyword(s):  
Motor Cortex ◽  
Skill Acquisition ◽  
Observational Learning ◽  
Primary Motor Cortex ◽  
Skill Learning ◽  
Neural Basis ◽  
Motor Representation ◽  
Sham Stimulation ◽  
Learning By Observation ◽  
Observational Practice

When learning a new motor skill, we benefit from watching others. It has been suggested that observation of others’ actions can build a motor representation in the observer, and as such, physical and observational learning might share a similar neural basis. If physical and observational learning share a similar neural basis, then motor cortex stimulation during observational practice should similarly enhance learning by observation as it does through physical practice. Here, we used transcranial direct-current stimulation (tDCS) to address whether anodal stimulation to M1 during observational training facilitates skill acquisition. Participants learned keypress sequences across four consecutive days of observational practice while receiving active or sham stimulation over M1. The results demonstrated that active stimulation provided no advantage to skill learning over sham stimulation. Further, Bayesian analyses revealed evidence in favour of the null hypothesis across our dependent measures. Our findings therefore provide no support for the hypothesis that excitatory M1 stimulation can enhance observational learning in a similar manner to physical learning. More generally, the results add to a growing literature that suggests that the effects of tDCS tend to be small, inconsistent, and hard to replicate. Future tDCS research should consider these factors when designing experimental procedures.

Reorganization of movement representations in primary motor cortex following focal ischemic infarcts in adult squirrel monkeys

1996 ◽  
Vol 75 (5) ◽  
pp. 2144-2149 ◽  
Author(s):  
R. J. Nudo ◽  
G. W. Milliken
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Squirrel Monkeys ◽  
Intracortical Microstimulation ◽  
Functional Reorganization ◽  
Cortex Area ◽  
Ischemic Infarct ◽  
Contralateral Hand ◽  
Forelimb Movement ◽  
Cortical Regions

1. Intracortical microstimulation (ICMS) techniques were used to derive detailed maps of distal forelimb movement representations in primary motor cortex (area 4) of adult squirrel monkeys before and a few months after a focal ischemic infarct. 2. Infarcts caused a marked but transient deficit in use of the contralateral hand, as evidenced by increased use of the ipsilateral hand, and reduced performance on a task requiring skilled digit use. 3. Infarcts resulted in a widespread reduction in the areal extent of digit representations adjacent to the lesion, and apparent increases in adjacent proximal representations. 4. We conclude that substantial functional reorganization occurs in primary motor cortex of adult primates following a focal ischemic infarct, but at least in the absence of postinfarct training, the movements formerly represented in the infarcted zone do not reappear in adjacent cortical regions.

scholarly journals Forelimb movements evoked by optogenetic stimulation of the macaque motor cortex

2019 ◽  
Author(s):  
Hidenori Watanabe ◽  
Hiromi Sano ◽  
Satomi Chiken ◽  
Kenta Kobayashi ◽  
Yuko Fukata ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Cortical Neurons ◽  
Primary Motor Cortex ◽  
Viral Vector ◽  
Single Pulse ◽  
Brain Functions ◽  
Optogenetic Stimulation ◽  
Indispensable Tool ◽  
Cag Promoter ◽  
Forelimb Movements

AbstractOptogenetics has become an indispensable tool for investigating brain functions. Although non-human primates are particularly useful models for understanding the functions and dysfunctions of the human brain, application of optogenetics to non-human primates is still limited. In the present study, we generated an effective adeno-associated viral vector serotype DJ to express channelrhodopsin-2 (ChR2) under the control of a strong ubiquitous CAG promoter and injected into the somatotopically identified forelimb region of the primary motor cortex in macaque monkeys. ChR2 was strongly expressed around the injection sites, and optogenetic intracortical microstimulation (oICMS) through a homemade optrode induced prominent cortical activity: Even single-pulse, short duration oICMS evoked long-lasting repetitive firings of cortical neurons. In addition, oICMS elicited distinct forelimb movements and muscle activity, which were comparable to those elicited by conventional electrical ICMS. The present study removed obstacles to optogenetic manipulation of neuronal activity and behaviors in non-human primates.

scholarly journals Familiarity with a Tool Influences Peripersonal Space and Primary Motor Cortex Excitability of Muscles Involved in Haptic Contact

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
M Biggio ◽  
A Bisio ◽  
L Avanzino ◽  
P Ruggeri ◽  
M Bove
Keyword(s):  
Motor Cortex ◽  
Multisensory Integration ◽  
Primary Motor Cortex ◽  
Cortical Excitability ◽  
Peripersonal Space ◽  
Motor Representation ◽  
Cortical Motor ◽  
Motor Cortex Excitability ◽  
Long Term Experience

Abstract Long-term experience with a tool stably enlarges peripersonal space (PPS). Also, gained experience with a tool modulates internal models of action. The aim of this work was to understand whether the familiarity with a tool influences both PPS and motor representation. Toward this goal, we tested in 13 expert fencers through a multisensory integration paradigm the embodiment in their PPS of a personal (pE) or a common (cE) épée. Then, we evaluated the primary motor cortex excitability of proximal (ECR) and distal (APB) muscles during a motor imagery (MI) task of an athletic gesture when athletes handled these tools. Results showed that pE enlarges subjects’ PPS, while cE does not. Moreover, during MI, handling tools increased cortical excitability of ECR muscle. Notably, APB’s cortical excitability during MI only increased with pE as a function of its embodiment in PPS. These findings indicate that the familiarity with a tool specifically enlarges PPS and modulates the cortical motor representation of those muscles involved in the haptic contact with it.

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