Figure 7.

PV Interneurons Strongly Modulate Cortical Responses to Layer V Stimulation

(A) Schematic of the in vivo experiment.

(B) Recordings from a ChR2-negative principal neuron in vivo showing blue light stimulation alone (Pre and Post) and combined blue and yellow light stimulation (PV-inhibition) during an activated state.

(C–E) Negative peak amplitude (C), area (D), and response probability (E) of light-evoked responses under the conditions shown in (B). n = 20 cells from 10 animals; one-way repeated-measures ANOVA.

(F) Schematic of the experimental configuration in slices.

(G) A Halo-expressing PV interneuron showing cell hyperpolarization upon yellow light (yellow bar).

(H) Scheme of the brain slice experiment; recorded cells were located both in layers II/III and V.

(I) Representative examples of IPSCs evoked in recorded cells by layer V stimulation before (Pre), during (PV-inhibition), and after (Post) photoinhibition of PV interneurons.

(J and K) Amplitude (J) and charge (K) of IPSCs under the different experimental conditions. n = 28 cells; one-way repeated-measures ANOVA.

(L) Same as in (A) and (B) but in the presence of whisker deflection.

(M) A ChR2-negative principal neuron in vivo showing the response to whisker stimulation (Whisker), whisker stimulation in the presence of blue light (Whisker + laser), and whisker stimulation in the presence of blue and yellow light (Whisker + laser + PV-inhibition) during an activated state.

(N–P) Positive peak amplitude (N), membrane potential value at the whisker response time peak (O), and area (P) for supragranular and infragranular ChR2-negative neurons under the different conditions shown in (M). n = 11 cells from 5 animals; one-way repeated-measures ANOVA.

See also Figures S5–S7.