Mechanisms of cerebral preconditioning. A Magnetic Resonance Imaging Study

• Applicant: Dr. Susanne Wegener
• Subject Area: Human Cognitive and Systems Neuroscience
• Term: from 2004 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5438145

Because treatment options for stroke remain unsatisfactory, there is tremendous interest in new ways of neuroprotection that might be feasible in humans, such as the induction of endogenous cerebral protection ("Ischemic tolerance") elicited by a sublethal toxic stimulus ("preconditioning"). In a recent study on stroke patients with antecedent transient ischemic attacks, we found evidence for the existence of ischemic tolerance in the human brain. The proposed project will address the following questions: 1) What factors elicited by preconditioning cause ischemic protection? 2) Is there a specific tissue "signature' of preconditioned tissue? 3) What distinguishes preconditioned tissue in a following ischemia from first ever ischemic brains? Magnetic Resonance Imaging (MRI) will be applied to a rat model of hypoxic preconditioning and focal ischemia, to assess parameters of cerebral perfusion and tissue integrity and their spatial and temporal relation to the development of tolerance. To identify a vascular component of preconditioning, MRI at 7 Tesla will include highly sophisticated arterial spin labeling techniques for perfusion weighted imaging, developed at the host institution. Co-registered histological data will provide information on the extend and character of ischemia-induced neurogenesis in tolerance induction.

• DFG Programme: Research Fellowships
• International Connection: USA
• Cooperation Partner: Professor Dr. Richard Buxton