Cerebrovascular CirculationCerebral ArteriesMiddle Cerebral ArteryPia MaterBlood Circulation TimeCerebral InfarctionBrainBlood Flow VelocityCerebral AngiographyCarbon DioxideUltrasonography, Doppler, TranscranialBrain IschemiaBasilar ArteryBlood PressureHypercapniaCerebral VeinsPapioCerebral PalsyVascular ResistanceHypocapniaArteriolesPartial PressureBlood CirculationXenon RadioisotopesHypotensionVasodilationIntracranial PressureBemegrideIntracranial Embolism and ThrombosisVasomotor SystemSubarachnoid HemorrhageCerebrovascular DisordersRegional Blood FlowBlood Gas AnalysisHyperventilationOxygenHomeostasisTrimethaphanIschemic Attack, TransientVertebral ArteryVasoconstrictionInfarction, Middle Cerebral ArteryHemodynamicsHypoxia, BrainVasodilator AgentsIntracranial EmbolismMalaria, CerebralAcetazolamideBlood-Brain BarrierExtracorporeal CirculationLaser-Doppler FlowmetryIntracranial AneurysmEmbolism, AirBlood VolumeOxygen ConsumptionCatsMicrocirculationCarotid ArteriesCerebral HemorrhageAnimals, NewbornPulmonary CirculationIndomethacinArteriesCarotid Artery, InternalAngiography, Digital SubtractionStrokeNitric OxideCarotid StenosisMagnetic Resonance ImagingSwineDisease Models, AnimalJugular VeinsNitroprussideTime FactorsAnoxiaEndothelium, VascularMagnetic Resonance AngiographyRats, Sprague-DawleyCollateral CirculationDogsTomography, X-Ray ComputedAcetylcholineVasoconstrictor AgentsBlood VesselsCarotid Artery DiseasesNitric Oxide SynthaseElectroencephalographyAnterior Cerebral ArteryHeart RatePosterior Cerebral ArteryProstaglandinsHypertensionDose-Response Relationship, DrugRabbitsCerebral Amyloid AngiopathyCerebral VentriclesBradykininSympathetic Nervous SystemEnterohepatic CirculationReference Values