Exploratory animal data on potential stroke therapies has not been predictive of clinical success. There are concerns over the design and conduct of pre-clinical studies, their reproducibility and generalizability. The response to this challenge was the NINDS Stroke Preclinical Assessment Network (SPAN), an unbiased multicenter platform for preclinical confirmatory studies in translational stroke research. The MGH team was among the six laboratories selected by the peer review for this first iteration of SPAN (SPAN-1). We made major contributions to the design of SPAN-1. MGH took charge of the MRI protocol for SPAN-1 and helped develop a fully automated analysis pipeline. We then contributed almost 400 animals in under 2 years to test six different acute stroke interventions. Each animal underwent two MRIs (days 2 and 30) and two neurological tests (days 7 and 28). Overall mortality was only ~10% during 28-day survival. Our technical losses amounted to just 17 animals. There were only 3 protocol deviations or violations. Our overarching aim is to repeat this success in the next iteration of SPAN (SPAN-2). We are an experienced team of clinical and basic scientists capable of adjusting to the needs of the network. MGH SPAN team has collectively published over 100 manuscripts using various focal cerebral ischemia models and acute and chronic neurological outcome readouts in rodents. MGH will also bring additional innovative approaches to SPAN-2, such as introducing MRI readouts for hemorrhagic transformation, blood-brain barrier (BBB) disruption and tractography. We will complement the latter with optical imaging of resting state functional connectivity (RSFC) at the end of the follow up period. Aim 1. Contribute to SPAN-2 as a testing laboratory. We pledge to repeat our success in SPAN-1, working as a team with the rest of the network and sustaining our high standards with built-in redundancies to ensure our resilience in the face of personnel changes and disruptive events such as pandemics and weather. Aim 2. Introduce innovative new structural and functional indices to enrich the SPAN readouts. We will go beyond recruiting subjects for the trial by introducing innovative readouts such as hemorrhage, edema, structural and functional connectivity, and histological analyses, which have not been part of SPAN-1. Aim 3. Test whether an unbiased, multicenter, randomized, and blinded preclinical trial network can confirm or refute the published exploratory efficacy and safety data. We hypothesize that SPAN will have the statistical power and an unbiased structure to provide conclusive evidence confirming or refuting published exploratory data of prospective cerebroprotective therapies in ischemic stroke in combination with reperfusion. For over a decade, we have advocated for and passionately supported the concept of an unbiased multicenter preclinical testing platform. We enthusiastically worked as part of SPAN-1 to ensure its success. And now we...