Figure 4.

LTPi-FFI Induces a Shift in Temporal Association of L5 PN Firing during Photo-Induced Rhythmic Activity

(A) Scheme of the recording configuration.

(B) Representative traces during a light ramp (blue, 1-s duration) protocol inducing rhythmic activity of L2/3 IPSCs (blue trace) and L5 EPSCs (red trace).

(C) Power spectra of the EPSCs and IPSCs of the cells shown in (B).

(D) Representative firing activity of a L5 PN during γ-activity in L2/3 before (Bsl, black trace) and after induction of LTPi-FFI (red trace).

(E) Spike probability during a cycle (blue trace) of the same L5 PN before (black) and after LTPi-FFI (red).

(F) Left: representative traces illustrating the association of a spike of a L5 PN (red trace) with the peak of oscillating IPSCs from a L2/3 PN (black trace). Right: population data of the time to oscillation peak in cells that underwent LTPI-FFI (circles) and cells in which the postsynaptic bursts had no effect (diamonds). ^∗p < 0.05, Wilcoxon matched-pairs signed-rank test (Bsl versus LTPi) and ^∗p < 0.05, Kruskal-Wallis test followed by Dunn’s multiple comparisons test (Bsl versus Bsl).

(G) Firing rates of LTPI-FFI (circles) and no LTPi cells (diamonds). Black and red dots (left), and black and gray diamonds (right) refer to PNs used for temporal association analysis. Cells indicated with blue and/or pink symbols had to be removed from the temporal association analysis because of spike sparsity. ^∗p < 0.05, paired t test (Bsl versus LTPi).

(H) Average population data of the membrane resting potentials of LTPI-FFI (circles) and no LTPi cells (diamonds).

Population data are illustrated as mean ± SEM.