Research reportTransient brain ischemia due to cardiac arrest causes irreversible long-lasting cognitive injury

Herein, we used a clinically-relevant model of 10 min cardiac arrest (CA) in Wistar rats. Histological analyses of the ischemic brains of old rats showed significant atrophy of CA1 sector of hippocampus (Nissl and NeuN stainings) corresponding with increase of glial fibrillary acidic protein expression. The long-term behavioral consequences of above manipulation producing global brain ischemia were assessed in young, middle-aged and old rats, i.e., 3-, 6- and 18-months post-treatment, respectively. In young animals no differences were found in the context-dependent memory in Fear Conditioning test. The most striking behavioral abnormalities were found in middle-aged rats (6 months post-ischemia). Ischemic rats showed hyperactivity and decreased level of anxiety in Open Field and problems with spatial learning and memory in a Novel Object Location test, T-maze and Morris Water Maze. In old animals, a decline of motor and cognitive functions was found not only in ischemic but also in sham/control ones. This study describes consequences of global brain ischemia in aging animals.

Research highlights▶ 10 min cardiac arrest (CA) in Wistar rats, produces atrophy of hippocampal CA1. ▶ CA results in hyperactivity and decreased anxiety at 6 months post-ischemia. ▶ CA produces cognitive deficits at 6 months post-ischemia. ▶ CA-evoked behavioral alterations are not observed at 18 months, as controls deteriorated too.