Figure 6.

In vivo photostimulation and photosilencing of transfected BA INs and PNs during extinction training. A, Schematic of approach to targeting BA INs and PNs in CCK-Cre single-transgenic mice with AAV5-Ef1a-DIO-hChR2(H134R)-EYFP-WRPE-pA or AAV5-Ef1a-DIO-eArch3.0-EYFP. B, Representative example of EYFP expression after virus transfection. C, Virus-transfected (EYFP-expressing) cells labeled with Cck mRNA, including example of cell labeled with Gad1 mRNA (white arrows, scale bar = 20 µm). D, Virus-transfected (EYFP-expressing) cells labeled with Cck mRNA, including example of cell labeled with Slc17a7 mRNA (white arrows, scale bar = 20 µm). E, Blue (ChR2 group) or green (eArch3.0 group) was shone during each CS presentation of extinction training. For fiber placement maps see Extended Data Figure 6-1. F, Photoexcitation in the ChR2 group during each CS presentation of extinction training increased freezing during training and light-free extinction retrieval the following day, relative to EYFP controls. Photosilencing in the eArch3.0 group during each CS presentation of extinction training reduced freezing on light-free extinction retrieval the following day, relative to EYFP controls; n = 12–27 per group; *p < 0.05, #p < 0.05 T0 versus T1 extinction training. Results of similar interventions on locomotion and anxiety level are presented in Extended Data Figure 6-2.