Tactile Discrimination Based on Intracortical Microstimulation in Primary Somatosensory Cortex in Sprague-Dawley Rats

Sensory cortical prostheses have the potential to aid people suffering from blindness, deafness or other sensory deficits by applying stimulation directly to the brain. Our main objective was to investigate if rats were able to perform tactile discrimination based on a natural, tactile input or based on artificially generated sensation. Four rats were first trained to touch a spinning wheel and to discriminate between two spinning velocities (65mm/s and 28mm/s). Secondly, the tactile stimulation was replaced by direct, intracortical stimulation. Rats were able to correctly discriminate between the two spinning velocities in up to 85% (66% ± 8 %) whereas the best discrimination performance during microstimulation decreased to 70% (57% ± 7 %). The work shows that rats are able to perform tactile discrimination, and it provides further insight into which sensations may be generated by direct cortical stimulation.