Grant funds are requested to support a new research program project aimed at the long-term goal of understanding how cell-cell interactions influence the pathogenesis of hypoxic-ischemic brain injury. Glutamatergic neurotransmission in particular has been implicated in the pathogenesis of hypoxic-ischemia neuronal death. While attention in the area has centered historically around N-methyl-D-aspartate (NMDA) receptor-mediated contributions to hypoxic brain damage, recent evidence has indicated that alpha-amino-3-hydroxy-5-methyl-4- isoxazolepropionate/kainate (AMPA/KA) receptors may also be important mediators of injury in the hypoxic-ischemic brain. Elucidation of several mechanisms underlying this AMPA/KA receptor mediation is the specific goal of the present application. The proposed experiments enlist the efforts of 8 faculty investigators, collaborating on 4 highly interlinked experimental Projects and 5 supporting Cores. Project 1 will investigate the contribution of AMPA/KA receptors to hypoxic neuronal injury in cortical cell cultures, with special attention to the minority subset of AMPA/KA receptors which gate Ca2+-permeable channels. Project II will harness a recent discovery that certain benzothiadiazides can modify AMPA/KA receptor desensitization, using these drugs as probes to study the role of AMPA/KA receptor desensitization in limiting hypoxic neuronal injury. Project III will use fura-2 videomicroscopy to examine the hypothesis that AMPA/KA receptor overactivation contributes to hypoxic neuronal injury by disrupting neuronal intracellular Ca2+ homeostasis. Project IV will explore the relationship between hypoxic AMPA/KA receptor activation and free radical-mediated cell damage. These experimental sections are supported by an administrative core (A); an animal (in vivo ischemia) core (B); a histology core (C); a computing and image analysis core (D); and a statistics core (E). taken together, proposed experiments will combine molecular, cellular, and whole animal approaches to answer several specific relevant to understanding the pathogenesis of hypoxic- ischemic brain damage. Information gathered from these studies may aid the future development of effective clinical therapies for stroke and cardiac arrest.
Showing the most recent 10 out of 122 publications
