Figure 4. Temporal dynamics of SWR-dependent modulation of interneuronal firing.

(A–C) Example raster plots (black dots) and spiking rate curves (in color) showing three typical patterns. Note the right-shifted positive peak with respect to SWR center (cyan bar) on B and C. (D) Three groups of interneurons whose discharges prefer distinct temporal windows relative to SWRs. Inset: summary of time of peak firing (vertical dashed lines on main panel) with respect to the middle of the SWRs (bars indicate median values): FSBCs+SOM (brown) 1.5[1^st quartile: −8, 3^rd quartile: 22.5]; NOS (blue): 98.5[56, 132]; CB1&n.t. (green) 296.5[285.5, 307.5] (P=0.0131, KW-ANOVA test, DF=2, n=16; completed with Mann-Whitney U test; *P=0.023, 0.017 and 0.041 (n=9, 2 and 5; Z=−2.00, −2.13 and 1.74) for brown vs. blue, brown vs. green and blue vs. green, respectively). (E) Example raster plot and spiking rate curve of an axo-axonic (chandelier) cell with a reduction in the firing rate that precedes SWRs by >1sec. Note the different time scale compared to C. (F) Experimental design for panels G and H. (G) Representative example of reduced firing rate when the strong current injection delivered through the juxtacellular pipette co-occurred with a SWR. (H) Significantly decreased spiking rate during SWRs in the experiments indicated in panels F and G. n=5, P=0.016, t=4.012, DF=4; paired t test.