Collagenase-Induced Intracerebral Hemorrhage in Mice

ICH was induced by injecting collagenase into the left striatum of mice according to a previously described method19 (link)45 (link). Briefly, mice were placed in a stereotaxic frame under anaesthesia with isoflurane. A burr hole was drilled into the skull, and type VII-S collagenase (0.075 U in 0.5 μl saline; Sigma, St. Louis, MO) was infused into the left striatum with a microinfusion pump at a constant rate of 0.1 μl/min. The needle tip was placed for haematoma induction to invade the middle of the striatum without damaging the motor cortex: 0.4 mm anterior and 2.0 mm lateral from the bregma, 3.0 mm below the skull. Sham-operated mice were infused with an equal volume of saline. Body temperature was maintained at 37 ± 0.5 °C during surgery. After surgery, mice were returned to their home cage. Vital conditions of the mice were monitored every day after ICH surgery.