An Endovascular Perforation Model of Subarachnoid Haemorrhage in Rat Produces Heterogeneous Infarcts that Increase with Blood Load.

Subarachnoid haemorrhage (SAH) is a devastating disease and a major burden on society. Despite this, pharmacological treatment options are limited. Appropriate animal modelling of SAH is essential for the development of neuroprotective drugs, but experimental SAH often fails to produce widespread neuronal loss, as frequently seen in humans. We report that a recently described modification of the endovascular perforation model in rat produced widespread heterogeneous infarcts 72 h after SAH. Cerebral blood flow (CBF) was monitored, with or without intracranial pressure (ICP) measurement, for 1 h after induction of SAH. Blood load size was assessed, and brain injury was quantified at 72 h using histological staining, blood brain barrier breakdown assessment and immunofluorescent imaging of neuronal viability and microglial activation. Results showed that ICP measurement allowed for faster recovery of CBF, potentially reducing brain injury. Larger subarachnoid blood loads predicted more extensive neuronal damage which was easily quantified with the combination of histological and immunohistochemical techniques. Thus, for the investigation of neuroprotective strategies after SAH, the present protocol produces quantifiable, clinically relevant, heterogeneous patterns of infarct due to large blood loads, high ICP and low CBF.