Naloxon

Viral injections were performed under aseptic conditions in Prox1::cre or C57BL/6 mice up to 10 months old. The mice were anesthetized with a mixture of Fentanyl (Rotexmedica, Germany), Midazolam (Rotexmedica, Germany), and Domitor (Orion Pharma, Finland) via intraperitoneal injection ( $0.05/5.0/0.5\mathrm{mg}/\mathrm{kg}$ ). Analgesia ( $0.05\mathrm{mg}/\mathrm{kg}$ of buprenorphine; Buprenovet, Bayer, Germany) was administered intraperitoneally prior to the injection, and Xylocain (AstraZeneca, Germany) was used for local anesthesia. Stereotaxic injections were performed using an injection frame (WPI Benchmark/Kopf) and a microprocessor-controlled minipump (World Precision Instruments, Sarasota, Florida), 1000 nl of the viral solution was injected bilaterally into the hippocampus (rAAV-DIO-eGFP; rAAV-syn-GFP; coordinates: rostrocaudal: $-2.1\mathrm{mm}$ from the Bregma; mediolateral: $\pm 1.2\mathrm{mm}$ from the midline; dorsoventral: $-2.1\mathrm{mm}$ ). After the injection, the scalp was sutured with PERMA-HAND Silk Suture (Ethicon), and an antibacterial ointment (Refobacin^®, Almirall, Germany) was applied, followed by the intraperitoneal injection of a mixture of Naloxon (B. Braun, Germany), Flumazenil (B. Braun, Germany), and Antisedan (Orion Pharma, Finland) ( $1.2/0.5/2.5\mathrm{mg}/\mathrm{kg}$ ). To prevent the wound pain, analgesia was administered on the 3 following days.