Enrofloxacin

OSN axotomies were performed as described previously with some modifications (Costanzo, 2000 (link)). The 8- to 12-week-old mice (both male and female) were anesthetized with ketamine (80 μg/g body weight) and xylazine (7 μg/g), and then given dexamethasone (0.1 μg/g; Kyoritsu Seiyaku) and enrofloxacin (5 μg/g; Pfizer) by subcutaneous injection to prevent brain edema and infection. A dental drill was used to thin the nasal skull of the OE–OB border region (along the cribriform plate). OSN axons projecting to the dorsal OB were transected along the cribriform plate with a micro knife for ophthalmic surgery (2.8 mm, 45° bevel up, Beaver Xstar Slit Knife, Beaver-Visitec International). After axotomy, a coverslip was put onto the craniotomy with dental cement, and the skin flap was sutured. In most experiments, only OSN axons projecting to the right OB were transected. In some experiments, the left or both sides were axotomized. Mice were administered with daily subcutaneous injection of dexamethasone (0.1 μg/g; Kyoritsu Seiyaku) and enrofloxacin (5 μg/g; Pfizer) for 5 consecutive days. For recovery, mice were placed in single-housed cages and kept for 3–84 d. In Figure 1B, a micro knife was labeled with 5% tetramethylrhodamine (TMR)-dextran (10 kDa; catalog #D1868, Thermo Fisher).