Organization of the forelimb area in squirrel monkey motor cortex: representation of digit, wrist, and elbow muscles

@article{Donoghue2004OrganizationOT,
  title={Organization of the forelimb area in squirrel monkey motor cortex: representation of digit, wrist, and elbow muscles},
  author={John P. Donoghue and Stephen J. Leibovic and Jerome N. Sanes},
  journal={Experimental Brain Research},
  year={2004},
  volume={89},
  pages={1-19}
}
SummaryThe EMG in 8 to 14 hand, forearm, and arm muscles evoked by intracortical electrical stimulation was recorded at 433 sites in layer V in the region of the forelimb area of the primary motor cortex (MI) of three squirrel monkeys during ketamine anesthesia. At each site, the EMG was recorded at movement threshold (T) and at 1.5T and 2T at each site (but ≤60 μA), and the threshold movement was noted. In the animals examined, the total MI forelimb area identified by movements or EMG occupied… 
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References

SHOWING 1-10 OF 49 REFERENCES
Digit-muscle responses evoked from multiple intracortical foci in monkey precentral motor cortex.
TLDR
The data suggest that the digit area of motor cortex does not have a simple organization in which each muscle is represented by a single focus, rather, each muscle has multiple foci that have varying degrees of efficacy in producing responses and with variable overlap onto foci of other muscles.
Patterns of facilitation and suppression of antagonist forelimb muscles from motor cortex sites in the awake monkey.
TLDR
Patterns of excitatory and inhibitory effects were produced in antagonistic forelimb muscles by single intracortical microstimuli applied to motor cortex sites in macaque monkeys performing ramp-and-hold wrist movements, suggesting that the cortically evoked suppression is mediated by polysynaptic relays.
Organization of the face representation in macaque motor cortex
TLDR
The face representation in precentral motor cortex in macaque monkeys was stimulated with microelectrodes with the most commonly evoked muscle response in zygomaticus, which retracts the corners of the mouth in expressions of fear and anger.
Topographic organization of baboon primary motor cortex: face, hand, forelimb, and shoulder representation.
TLDR
The results suggest that the baboon motor cortex is topographically organized; however, embedded within this overall pattern lies a fine-grained mosaic incorporating multiple representations of the same muscle.
Microstimulation mapping of precentral cortex during trained movements.
TLDR
Both excitation and inhibition of muscles could be produced with ICMS of precentral cortex when the animal was performing a task involving the muscles being mapped, and different types of movements involving a single muscle are represented at different locations within this region.
The relationship of corpus callosum connections to electrical stimulation maps of motor, supplementary motor, and the frontal eye fields in owl monkeys
TLDR
The somatotopic organization of M‐I was neither a single topographic representation, nor two serial or mirror symmetric representations, nor a “nesting about joints” representation, and is more adequately described as a mosaic of regions, each representing movements of a restricted part of the body, with multiple representations of movements that tend to be somatOTopically related.
Postspike facilitation of forelimb muscle activity by primate corticomotoneuronal cells.
TLDR
In macaque monkeys making rampand-hold wrist movements against elastic loads, activity of task-related motor cortex cells and specific wrist and finger muscles was recorded and postspike facilitation (PSF) of average EMG activity was recorded.
Dynamic organization of primary motor cortex output to target muscles in adult rats II. Rapid reorganization following motor nerve lesions
TLDR
The results indicated that the output circuits of MI can be quickly reorganized by nerve lesions in adult mammals.
Dynamic organization of primary motor cortex output to target muscles in adult rats I. Long-term patterns of reorganization following motor or mixed peripheral nerve lesions
TLDR
The results indicate that the amount of cortex controlling a group of muscles and the strength of the relationship between a cortical locus with its target muscles is modified by nerve lesions in adult mammals.
Relationship of intrinsic connections to forelimb movement representations in monkey motor cortex: a correlative anatomic and physiological study.
TLDR
Data suggest that extensive, horizontally oriented, intrinsic axon collaterals provide inputs to many different Forelimb movement representations and may be recruited during complex movements to coordinate the activity of motor cortical zones whose predominant output is to forelimb muscle groups acting synchronously.
...
1
2
3
4
5
...