Collagenase-Induced Intracerebral Hemorrhage Model

ICH was induced by intrastriatal injection of Bacterial collagenase into the right basal ganglia as previously described [14 (link)]. Briefly, mice were anesthetized with ketamine (100 mg/kg) and xylazine (10 mg/kg) (2:1 vol/vol, intraperitoneal injection) and positioned prone in a stereotaxic head frame. Bacterial collagenase (0.075 units, type VII-S; Sigma-Aldrich, St. Louis, MO) was dissolved in 0.5 μL PBS and infused into the right basal ganglia at a rate of 0.1667 μL/min, using an infusion pump (Stoelting, IL). The needle was left for an additional 5 min to prevent possible leakage of the collagenase solution, and withdrawn slowly at a rate of 1 mm/min. After removal of the needle, the cranial burr hole was sealed with bone wax, the incision was sutured, and 0.4 mL of normal saline was injected subcutaneously, and the mice were allowed to recover. The sham operation was performed with PBS only. All ICH animals with hematoma and neurological deficits were included. Animals that died before experimental endpoints reached were replaced with new animals. Animals with no hematoma were excluded.