Centers and Institutes
Published November 10, 2023 | Version v1
Journal article Open

Microstimulation of human somatosensory cortex evokes task-dependent, spatially patterned responses in motor cortex

Creators

  • 1. University of Chicago
  • 2. University of Pittsburgh
  • 3. Schwab Rehabilitation Hospital
  • 4. Northwestern University

Description

The primary motor (M1) and somatosensory (S1) cortices play critical roles in motor control but the signaling between these structures is poorly understood. To fill this gap, we recorded – in three participants in an ongoing human clinical trial (NCT01894802) for people with paralyzed hands – the responses evoked in the hand and arm representations of M1 during intracortical microstimulation (ICMS) in the hand representation of S1. We found that ICMS of S1 activated some M1 neurons at short, fixed latencies consistent with monosynaptic activation. Additionally, most of the ICMS-evoked responses in M1 were more variable in time, suggesting indirect effects of stimulation. The spatial pattern of M1 activation varied systematically: S1 electrodes that elicited percepts in a finger preferentially activated M1 neurons excited during that finger's movement. Moreover, the indirect effects of S1 ICMS on M1 were context dependent, such that the magnitude and even sign relative to baseline varied across tasks. We tested the implications of these effects for brain-control of a virtual hand, in which ICMS conveyed tactile feedback. While ICMS-evoked activation of M1 disrupted decoder performance, this disruption was minimized using biomimetic stimulation, which emphasizes contact transients at the onset and offset of grasp, and reduces sustained stimulation.

Data availability

The deidentified data generated in this study have been deposited in the Data Archive BRAIN Initiative (DABI) under project code 6281M47AHII3. The data are available under restricted access for participant privacy, access can be obtained upon request to the study PIs by an investigator who is prepared to securely handle data resulting from human research. Source data are provided with this paper.

Custom code used for analysis is available through Github (https://doi.org/10.5281/zenodo.8408314). Code used for data collection can be made available upon request to the study PIs.

Files

Microstimulation-of-human-somatosensory-cortex-evokes-task-dependent-spatially-patterned-responses-in-motor-cortex.pdf

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Additional details

Identifiers

DOI
10.1038/s41467-023-43140-2
Other
oai:uchicago.tind.io:9680

Funding

NINDS
UH3 NS107714
NINDS
R35 NS122333

UChicago Information

Division(s)
Biological Sciences Division
Department(s)
Computational Neuroscience, Neurological Surgery, Organismal Biology and Anatomy
Center(s) or Institute(s)
Neuroscience Institute