Effect of activating or inhibiting cells in the superior colliculus on driving avoidance responses in the absence of the ACS. A, Schematic of the superior colliculus cells inhibited in the experiments shown in B and C. B, Effect of green light applied in the superior colliculus on LCS alone trials for animals that express Arch in GABAergic (Vgat-SC-Arch) or putative glutamatergic (CaMKII-SC-Arch) cells in the superior colliculus. The asterisks highlight nonsignificant difference versus ACS trials. C, Trial speed, trial velocity, and intertrial speed for the data in B. The asterisks highlight nonsignificant difference versus ACS trials. D, Schematic of the superior colliculus cells activated in the experiments shown in E and F. E, Effect of blue light applied in the superior colliculus on LCS alone trials for animals that express ChR2 in GABAergic (Vgat-SC-ChR2) or putative glutamatergic (CaMKII-SC-ChR2) cells in the superior colliculus. The asterisks highlight nonsignificant difference versus ACS trials. F, Trial speed, trial velocity, and intertrial speed for the data in E. The asterisks highlight nonsignificant difference versus ACS trials.