Project Summary/Abstract The Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a central mediator of two opposing forms of NMDA- receptor (NMDAR)-dependent synaptic plasticity: long-term potentiation (LTP) and depression (LTD). Pathological overstimulation of NMDARs during cerebral ischemia causes excitotoxic neuronal cell death, and we have recently shown that CaMKII also mediates the neuronal damage after global cerebral ischemia (GCI). Importantly, in vivo injection of our optimized CaMKII inhibitor (tatCN19o) provided significant neuroprotection after GCI in models that closely mimic the most relevant human conditions: cardiopulmonary resuscitation (CPR) after cardiac arrest in mice or after ventricular fibrillations in pig (unpublished). CaMKII inhibition (i) was conducted at a highly clinically relevant timepoint for these conditions (30 min after CPR); (ii) was effective in conjunction with current standard of care (therapeutic hypothermia); and (iii) protected not only from neuronal cell death, but also from the long-lasting functional impairments in LTP that are seen in the surviving neurons. In order to enable testing in humans, this SBIR project will conduct the studies required for a successful IND- application with the FDA, specifically including complete toxicology and safety pharmacology. In this phase I proposal, we will first complete the final therapeutically relevant piece of biochemical characterization of the inhibitor. Then, we will initiate the PK studies that are required for an IND application (which first requires a validation of a method for detection of our inhibitor in serum of the tested species).