An 18% (w/v) stock solution was prepared by slowly dissolving poloxamer 407 (Sigma-Aldrich Cat# 16758) in sterile water. LiCl powder (42.39 g/mol) (Sigma-Aldrich Cat# L7026) was reconstituted in the 18% poloxamer 407 solution, yielding a final concentration of 1 mM as the low dose and 2 mM as the high dose, and stored overnight in a refrigerator at 4°C to ensure complete dissolution. The 18% poloxamer 407 solution is liquid in the refrigerator and room temperature but becomes highly viscous at body temperature.
The animals were anesthetized by an intraperitoneal injection of tiletamine–zolazepam (30 mg/kg) and xylazine (10 mg/kg) and positioned right ear-down. A postauricular skin incision was made, and the subcutaneous tissues and superficial fascia of the neck were bluntly dissected. After exposing the otic bulla, a tiny hole was made and enlarged until the round-window membrane was clearly visible (Fig 1 ). A 16G needle was positioned within the round-window niche, and 50 μl of the poloxamer solution was injected using a 1 mL syringe over the round-window membrane. The hole was sealed with muscle, and the wound was closed with 4–0 Vicryl sutures (Ethicon). Intramuscular injection of ketamine (10mg/kg) was applied after surgery (prior to anesthetic recovery) to minimize animal suffering.
The animals were anesthetized by an intraperitoneal injection of tiletamine–zolazepam (30 mg/kg) and xylazine (10 mg/kg) and positioned right ear-down. A postauricular skin incision was made, and the subcutaneous tissues and superficial fascia of the neck were bluntly dissected. After exposing the otic bulla, a tiny hole was made and enlarged until the round-window membrane was clearly visible (