Figure 4. Coarseness preferring neurons as determined by extracellular single unit recordings.
Multi electrode single unit recordings were performed using multi-contact extracellular electrodes from the S1 barrel cortex. (A) Example of PSTHs from two neurons in response to different texture coarseness (CD, P320, P600 P1000). Each PSTH was acquired during artificial whisking (10 whisks applied at 5.5 Hz) against CD and three textures (P320, P600, and P1000). The responses of 170 consecutive artificial whisk trains are summed and presented in 10-ms time bins. The underlying gray line designates the time of whisking train. Note that the two neurons prefer different coarsenesses. The neuron presented on the right preferred the P1000 texture, while the neuron shown on the left prefer the P600 texture. (B) A summary of the responses acquired from single unit experiments (altogether 293 neurons from 19 rats). Responses were divided according to the percentage of neurons that were texture coarseness preferring (S.I. ≥ 0.35), non-preferring (NP; S.I. < 0.35) or non-responsive (NR) to all textures examined. (C) The coarseness preferring neurons were further subdivided to neurons that preferred either P1000, P600, P320, P120 textures or CD. (D) Cumulative histogram of S.I. calculated from the single unit recordings of all responsive neurons neurons.