Hypoxia-Ischemia, BrainAnoxiaAnimals, NewbornPlethysmography, Whole BodyStrokeHypoxia, BrainBrain IschemiaIschemiaRats, Sprague-DawleyCell HypoxiaPia MaterHypercapniaNeuroprotective AgentsMyocardial IschemiaHypotensionBrainCerebrovascular CirculationDisease Models, AnimalCell DeathRats, WistarNeuronsReperfusion InjuryIschemic Attack, TransientCerebrovascular Disorders