Presenter

Cassandra Wilkinson, Department of Psychology, University of Alberta

Abstract

Large intracranial bleeds are often devastating. One reason for this is that they take up a substantial portion of the limited space in the skull. This drives up intracranial pressure (ICP), which can cause death. In rat models, we discovered that many brain cells actually shrink and pack closer together, likely to make space for the blood clot. We tested this hypothesis in rats given a large intracerebral hemorrhage (ICH) and a ventricular shunt to drain fluid from the brain and lower ICP. Rats had either open shunts that drained fluid or blocked shunts to maintain high pressure after the ICH. Then, we compared brain cell density and volume to determine if attenuating ICP increases also reduced the cell shrinking. Rats that had open shunts had less shrinking (p=0.01), indicating that high ICP is necessary for cell shrinking after large strokes. Next, we wondered which genes regulate these cell volume changes. Rats were given an ICH and tissue samples from an uninjured region with cell shrinking (hippocampus) and the injured brain region (striatum) were taken. We quantified which genes were differentially expressed using an RNA microarray. 483 genes had significantly different expression in the uninjured hippocampus of ICH rats compared to controls, some of which may play a role in cell shrinking after ICH. Cell shrinking has implications for neuronal function (behaviour) and survival after ICH. Future studies will examine augmenting cell shrinking and mitigating side effects.

Poster

Authors & Affiliations

C.M. Wilkinson (Psychology Department, University of Alberta), G.C. Jickling (Department of Neurology, University of Alberta), F Colbourne (Psychology Department and Neuroscience and Mental Health Institute, University of Alberta)