High Stimulus-Related Information in Barrel Cortex Inhibitory Interneurons
Fig 1
Representation of single neural responses by spike counts and spike patterns.
(A) Schematic illustration of experimental setup for selective mechanical stimulation of single whiskers and simultaneous VSD imaging or multi-electrode recordings in four barrel-related columns. (B) Illustration of the 8x16 channels probe showing shank and site spacing, position of the barrels C0 to D3, and the location of the cortical layers relative to the electrode sites. (C) Activity of an inhibitory neuron located at L4 of the barrel D1 in response to principal whisker (PW, upper part) and neighboring whisker (NW, lower part) deflections. Five illustrative trials are plotted for each condition. From the original raster plots (left side), spike counts in a 50 ms time window (middle) and spike pattern vectors of 5 ms bin size (right side) were computed to represent the activity in each single trial. (D) Discrimination capacity of the two selected response representations (spike counts and patterns). Left side, distribution of spike counts after PW vs. NW stimulation (200 trials each). Right side, distribution of spike patterns. Note that the overlap of the two distributions is lower for spike patterns than spike counts, thus accounting for higher values of mutual information (Im).