Figure 1.

Burst Firing of L5 PNs Selectively Potentiates Feedforward GABAergic Input

(A) In utero electroporation of ChR2 and red fluorescent protein (RFP) in L2/3 PNs of the mouse S1.

(B) Scheme of the recording configuration.

(C) Average (10 sweeps) current-clamp traces of the EPSP-IPSP composite response recorded in L5 PNs upon photostimulation of L2/3 PNs before (black, top) and after (bottom, red) inducing LTPi.

(D) LTPi of light-IPSPs (top graph) of the cell shown in (C). The bottom graphs indicate light-EPSP slope, input resistance (Rin), and resting membrane potential (Vm) of the same cell.

(E) Population graph of LTPi in L5 PNs.

(F) Plot illustrating the relative change of light-IPSPs in response to burst firing of individual PNs (after 20 min). Dark circles, LTPi-expressing PNs; light gray circles, PNs not expressing LTPi; Bsl, baseline.

(G) Graphs showing average depolarizing slopes, areas, and the EPSP/IPSP ratio of composite PSPs in Bsl and after postsynaptic bursts. In some cases, the error bars are too small to be visible. n.s., not significant. ^∗p < 0.05, ^∗∗p < 0.01, with paired t test.

Population data are illustrated as mean ± SEM.