Long-term stability of sensitivity to intracortical microstimulation of somatosensory cortex.
OBJECTIVE
The dexterous manipulation of objects depends heavily on somatosensory signals from the limb. The development of anthropomorphic robotic arms and of algorithms to decode intended movements from neuronal signals has stimulated the need to restore somatosensation for use in upper-limb neuroprostheses. Without touch and proprioception, patients have difficulty controlling prosthetic limbs to a level that justifies the required invasive surgery. Intracortical microstimulation (ICMS) through chronically implanted electrode arrays has the potential to provide rich and intuitive sensory feedback. This approach to sensory restoration requires, however, that the evoked sensations remain stable over time.


METHODS
To investigate the stability of ICMS-evoked sensations, we measured the ability of non-human primates to detect ICMS over experimental sessions that spanned years.


RESULTS
We found that the performance of the animals remained highly stable over time, even when they were tested with electrodes that had experienced extensive stimulation.


CONCLUSIONS
Given the stability of the sensations that it evokes, ICMS may thus be a viable approach for sensory restoration.
Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA.
Thierri
T
Callier
Erik W
EW
Schluter
Gregg A
GA
Tabot
Lee E
LE
Miller
Francesco V
FV
Tenore
Sliman J
SJ
Bensmaia
D000818:Animals; D002540:Cerebral Cortex; D004558:Electric Stimulation / Q000295:instrumentation*; D004567:Electrodes, Implanted; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D008137:Longitudinal Studies; D008253:Macaca mulatta; D008297:Male; D008839:Microelectrodes; D015203:Reproducibility of Results; D012677:Sensation / Q000502:physiology*; D012680:Sensitivity and Specificity; D013003:Somatosensory Cortex / Q000502:physiology*