A spinal origin for the obligate flexor synergy in the non-human primate: Implications for control of reaching
Glover, I. S.; Baker, A. M.; Krakauer, J. W.; Baker, S. N.
Show abstract
Stroke survivors frequently develop the flexor synergy, an obligate co-contraction of shoulder abductors and elbow flexors; the neural substrate has proven elusive. Here we trained healthy monkeys to generate isometric elbow and shoulder torques to move an on-screen cursor, and recorded neuron firing from motor cortical areas and the reticular formation. In all regions we found cells correlated with activity around a single joint. Neurons coding co-contractions showed a bias towards combinations orthogonal to the post-stroke flexor synergy, e.g. shoulder abduction with elbow extension. Threshold microstimulation in the spinal cord but not in either motor cortex or the reticular formation generated coactivation aligned to the flexor synergy. We suggest the evolution of prehension required descending systems either to control or bypass locomotion-dedicated spinal circuits. Loss of descending input after stroke constrains the upper limb to spinal synergies best suited to primitive locomotor functions.
Matching journals
The top 5 journals account for 50% of the predicted probability mass.
Similar papers in this journal
- Distinct neural representations during a brain-machine interface and manual reaching task in motor cortex, prefrontal cortex, and striatum 95%
- “Characteristics and stability of sensorimotor activity driven by isolated-muscle group activation in a human with tetraplegia” 94%
- Calretinin-expressing islet cells: a source of pre- and post-synaptic inhibition of non-peptidergic nociceptor input to the mouse spinal cord 94%
Similar papers in this journal
- Movement initiation and grasp representation in premotor and primary motor cortex mirror neurons 95%
- Distinct population code for movement kinematics and changes of ongoing movements in human subthalamic nucleus 95%
- Poor matching of action codes challenges 'mirroring' in macaque F5 mirror neurons 95%
Similar papers in this journal
- Recruitment Of Upper-Limb Motoneurons With Epidural Electrical Stimulation Of The Primate Cervical Spinal Cord 95%
- Microstimulation of human somatosensory cortex evokes task-dependent, spatially patterned responses in motor cortex 94%
- Wide-field calcium imaging of cortical activation and functional connectivity in externally- and internally-driven locomotion 94%
"Similar papers" are the closest papers from that journal in the model's embedding space. They show what the match is built on, but the ranking comes mostly from a classifier over the whole training set, not from these examples alone.