Bx61vs

Mice were deep anesthetized with tribromoethanol and perfused with 10 ml of PBS followed by 10 ml of fixative (4% paraformaldehyde diluted in PBS). The brains were removed and post-fixed in 4°C overnight and then immersed in 30% sucrose solution for two days before being sectioned at 50 pm thicknesses on a cryostat (Leica CM3050 S). The free-floating brain sections were collected in PBS. For injection site verification, the sections were directly mounted onto glass slides with Vectashield mounting medium with DAPI. For tracing experiments, one out of every five sections were collected for the whole brain. For immunohistochemistry, standard procedures^{3 (link)} were followed. We used primary antibodies to SST (rabbit, BMA Biomedicals, cat. no. T-4103, 1:1000)^{25 (link)} and PKCdelta (mouse, BD Biosciences, cat. no. 610398, 1:1000)^{19 (link)}. A scanning microscope (BX61VS, Olympus) was used to scan fluorescent images for whole brain slices and a confocal microscope (Nikon A1) was used for higher resolution imaging. To image green signals in CTB-488 and SST-Ai14 co-localization experiments, a 500–530 nm virtual filter (spectral detector mode) was used instead of the default 500–550 nm filter (standard PMTs) in order to prevent leakage of SST-AM4 red signals into the green channel.