A1 16 poly2 5mm 50s 177 a16

For electrophysiology recording from behaving mice, the body of the mouse was placed in a metal tube (2.9 cm inner diameter) and the headplate was fixed on a holder. While the animal was under gas anaesthesia (1.5% isoflurane in oxygen), a craniotomy (~1 mm diameter) was made over the target area in the dmPFC (center AP +1.8–2.1 mm, ML 0.3–0.5 mm). A silicon probe (A1×16-Poly2-5mm-50s-177-A16, 16 active channels separated by 50 μm, NeuroNexus Technologies) was inserted using a motorized micromanipulator (MX7630R, Siskiyou). Signals were recorded with the Cheetah 32 channel acquisition system (Neuralynx), filtered at 0.6–6 kHz and sampled at 30 kHz. After every daily experiment, the craniotomy was sealed with a silicone elastomer (Kwik-Cast, World Precision Instruments). At the end of the experiment, a silicon probe coated with DiI was inserted to mark the recording tract. 5 VIP-ChR2 mice and 6 SST-ChR2 mice were used for these experiments.