Active and passive touch are differentially represented in the mouse somatosensory thalamus
Fig 5
Inhibition of the barrel cortex (BC) increases VPM and POm correlation with free whisking but strongly attenuates POm whisker deflection responses.
(A) Experimental setup. BC was optogenetically suppressed while juxta-cellular recordings were made from single neurons in VPM and POm. A single whisker was deflected with air puffs. (B) Spike rates during quiescence (Q = no whisking) and during whisking (W) during BC suppression (Laser on) and control conditions (Laser off). Individual neurons (black lines: whisking rate significantly different from base rate (p < 0.05, shuffle test, see Methods), gray: non-significant change) and population means (VPM blue line, POm purple line). (C) Polar plot of phase-SNR (radius) and preferred phase (angle) for VPM (left, blue) and POm (right, purple) neurons, during control condition (Laser Off, circles) and during BC inactivation (Laser On, diamonds). Filled markers indicate significantly phase-modulated neurons per condition. Phase zero refers to a fully protracted position. (D) VPM (left) and POm (right) phase-SNRs when the laser was on or off. Individual neurons (black lines: significant phase modulation (p < 0.05, Kuiper test) during laser on condition, gray lines: nonsignificant phase modulation) and population means (VPM blue line, POm purple line). Percentage of neurons significantly modulated in laser on/off conditions. (E) VPM (left) and POm (right) responses to air puffs (teal) in control condition (Laser off). Top: heatmaps of individual neuron PSTHs normalized to baseline before air puff and ordered by peak response latency. Bottom: mean population PSTHs and whisker angles (orange). (F) Same neurons as in E but when the BC was inactivated (Laser on, light blue). (G) VPM spike rates during baseline and in response to air puffs during control conditions (Laser off) and during BC inactivation (Laser on). Baseline: 50 ms windows before, Puff: 50 ms after. Individual neurons (black lines: rate increase p < 0.05, gray lines: non-significant increase) and population means (blue lines). (H) same as G but for POm. (I) Rate modulation index in comparison to baseline for puff-evoked responses with and without BC inactivation. Individual neurons (black) and population means for VPM (blue) and POm (purple), zero modulation indicated by red-dashed line. Asterisks represent p-values (*p < 0.05, **p < 0.01, ***p < 0.001); 5G–5H, 5I between conditions: two-sided Wilcoxon signed-rank test; 5I between neuron populations: two-sided Wilcoxon ranked-sum test; Individual neuron comparison (5B, 5D, 5G, 5H): two-sided Wilcoxon signed-rank test; exact p values, N numbers in S1 Table. Data and code underlying this figure can be found here: https://doi.org/10.5281/zenodo.14691035. Source data for panels B, D, G, H, I in S4 Data.