EDN1 and ischemia: Therefore, we attempted to produce brain infarcts in middle-aged rats, but with a larger dose of Et-1 (150 pmol), in order to: (1) determine the size of brain infarcts after unilateral Et-1 infusion near the MCA in middle-aged rats and to compare it to that in young rats; (2) determine the ischemia-induced asymmetry of sensory-motor and reflex functions in middle-aged rats in comparison with that in young rats; and (3) examine the hemispheric asymmetry in the EEG in both groups subjected to ischemia.