Figure 6: Set-shifting performance requires PFC-VMS and PFC-MDT activity following rule-informative trials.

A. Cre-mediated expression of gtACR-FusionRed in PFC-VMS neurons, and fiber tracks from chronically implanted bilateral optical fibers (fixed dissue, DAPI in blue).

B. Electrophysiological demonstration of gtACR-mediated silencing. Left: a trace of spontaneous activity (7 seconds), with a 2-second light epoch interposed (1.5mW, 470nm light, 200μm fiber, PFC, see Methods). Right: rasters of 50 sweeps for each of four light intensities: 0.3mW (top), 0.8mW, 1.5mW, and 3.0mW (bottom).

C. Schematic diagram of light delivery conditions. Light was delivered during the inter-trial interval following incongruent trials, following congruent trials, or during incongruent trials.

D. Effect of light stimulation following incongruent trials on incongruent trial performance (fraction of trials correct). Left: viral control animals (td-Tomato expressed in PFC); second from left: animals with pan-neuronal expression of stgtACR2 in PFC; third from left: animals with stgtACR2 expressed in PFC-VMS projection neurons; right: animals with stgtACR2 expressed in PFC-MDT projection neurons. N=13, 16, 17, 18 resp. Sign rank p=0.4, 0.0005, 0.007, 0.01, resp.

E. Effect of light stimulation during ITIs following incongruent trials on congruent trial performance (proportion of trials correct). Left to right: as in (a) above. N=13, 16, 17, 18, resp. Sign rank p=0.9, 0.5, 0.9, 0.07, resp.

F. Effect of light stimulation during ITIs following congruent trials on incongruent trial performance. N=18, 18, resp. Sign rank p=0.1 and 0.1, resp.

G. Effect of light stimulation during trials (stimulus presentation + response window) on incongruent trial performance. N=10 and 10, resp. Sign rank p=0.4 and 0.4, resp. Right: Effect of light delivered to posterior parietal cortex (PPC) during incongruent trials on incongruent trial performance (N=9 animals, ranksum p=0.02, opsin-negative control group, N=8 animals, p=0.74).