Figure 4.

L6CCs Gate L5PT Output

(A) Principal component analysis of the spatiotemporal properties of synaptic input patterns to L5PT models. 92% of PC₁ reflect the net excitatory input to the proximal dendrites of L5PTs within a time window of 8–16 ms after the stimulus onset.

(B) Synchronous proximal drive (SPD) is an almost perfect predictor for the probability of AP responses in the simulations.

(C) Iso-probability plots of AP responses as a function of the number and synchrony of synaptic inputs to the proximal dendrites of L5PTs. Bold lines represent the average AP probability measured in vivo for PW, SW, and 2^nd SW stimulations, respectively. Comparison between these general input/output relationships and the empirically determined properties of the TC and different IC cell types is shown (mean ± SD).

(D) PSTHs and average wRFs analogous to Figures 3D/3E but without stimulus-evoked inputs from the TC and different IC cell types.

(E) Increase in AP probabilities of L5PTs with versus without stimulus-evoked inputs from the TC and different IC cell types as shown in (D).

(F) Contribution from all versus somatotopically aligned L6CCs to the AP responses of L5PTs.