Cerebral Ventricle NeoplasmsCerebral VentriclesInjections, IntraventricularFourth VentricleCisterna MagnaHeart VentriclesShiveringBrain StemCerebral ArteriesInjectionsBrainBody TemperatureLateral VentriclesHypothalamusCerebrospinal FluidPempidineCerebral InfarctionEpendymaBody Temperature RegulationHypnosis, AnestheticPhysostigmineCatsHexamethonium CompoundsTranylcypromineThird VentricleEvoked Potentials, Auditory, Brain StemSubarachnoid SpaceCerebral PalsyCerebrovascular CirculationConsciousnessSerotoninHydrocephalusPerfusionHistamine AgentsMiddle Cerebral ArteryPyrogensDogsNorepinephrineChoroid PlexusRats, Sprague-DawleyBlood PressureRats, WistarTime FactorsPhentolamineLysergic Acid DiethylamideDrinkingCerebral Angiography