Behavioural effects of single-cell stimulation in Barrel cortex

Rodents rely mostly on their whiskers to explore their environment and a large part of their primary somatosensory cortex, called barrel cortex, is dedicated to whisker perception. Several different cell types in barrel cortex were stimulated to explore its effect on perception of a simple whisker movement. For long, it was suspected that interneurons have an inhibitory effect on behaviour and perception. Our results show that stimulation of a single fast-spiking putative interneuron or a highly sensitive whisker responsive cell can actually enhance perception of a simple whisker movement. When stimulating a single non-responsive pyramidal cell, no perceptual bias was detected. These results suggest that animals decode neural activity in a detection task using a selective subset of neurons in the barrel cortex. Secondly, because it is known that stimulation of multiple cells in barrel cortex can lead to whisker movement, we wanted to determine which cell types play a role in this process. Several different cell types in layer 5 of barrel cortex were stimulated one at a time, but we had to conclude that single-cell stimulation in barrel cortex is not sufficient to elicit whisker movements.