Measuring Cerebral Vasospasm after Subarachnoid Hemorrhage in Mice

Subarachnoid hemorrhage (SAH) is a devastating illness, and patients who survive are still at risk for long-term neurological deficits. Cerebral vasospasm is one of several contributing factors to morbidity and mortality after SAH. Preclinical animal models are essential resources to investigate pathophysiology and novel therapeutics. This protocol provides a two-phase method for both inducing SAH in mice and evaluating delayed cerebral vasospasm by measuring cerebral artery diameter. In the first step, an anterior circulation autologous blood injection method is used to reproduce the most common anatomical location of human non-traumatic SAH and reliably control the volume and distribution of hemorrhage. The duration of this procedure is approximately 20 min per animal. Next, on post-SAH day 5, the cerebral vasculature is fixed and casted using a gelatin-dye solution before removing the brain for imaging. Finally, the diameter of many cerebral arteries can be measured simultaneously using a variety of image analysis software platforms. These procedures are rigorous and reproducible while also offering a time- and resource-efficient method for studying the pathophysiology of SAH and cerebral vasospasm.