Effect of activating or inhibiting cells in the PPT on avoidance responses driven by the ACS. A, Schematic of the PPT cells inhibited in the experiments shown in B and C. B, Effect of green light applied in the PPT on ACS+LCS trials for animals that express Arch in GABAergic (Vgat-PPT-Arch) or putative glutamatergic (CaMKII-PPT-Arch) cells in PPT. C, Trial speed, trial velocity, and intertrial speed for the data in B. D, Schematic of the PPT cells activated in the experiments shown in E and F. E, Effect of blue light applied in the PPT on ACS+LCS trials for animals that express ChR2 in GABAergic (Vgat-PPT-ChR2) or putative glutamatergic (CaMKII-PPT-ChR2) cells in the PPT. F, Trial speed, trial velocity, and intertrial speed for the data in E.