Histological and Elemental Changes in Ischemic Stroke

Stroke is a leading cause of serious long-term disability in adults and a leading cause of death in developed nations. Following an ischemic stroke the metabolic profile of the affected tissue is significantly altered, with the infarct representing the most severely affected tissue, and the surrounding penumbra, or peri-infarct zone (PIZ), containing a gradient of metabolic states progressing from severely impacted toward an otherwise healthy profile. The penumbra contains potentially salvageable tissue and is the focus in many stroke treatments. In this chapter, we employ the photothrombotic stroke model (a widely used animal model for studying focal ischemia) to study the histopathological and bioelemental changes that occur post-stroke. Synchrotron-based X-ray fluorescence imaging allows simultaneous measurement of multiple elements in situ within biological tissues, as their naturally-occurring concentrations. Images of elemental distributions are compared to conventional histopathological changes in the infarct and penumbra. Understanding the bioelemental changes associated with the post-stroke brain provides opportunities to expand our understanding of the underlying cellular and tissue changes associated with ischemic stroke and can ultimately be used to guide development of future treatment methods targeting the penumbra.