Effect of adaptation to high-altitude hypoxia in early ontogeny on higher nervous activity

Newborn male and female Wistar rats were adapted to hypoxia in a pressure chamber. Adaptation began at an “altitude” of 1000 m for 1 h daily, after which the duration and intensity of exposure were gradually increased so that, starting from the 17th day, the animals were adapted to an altitude of 5000 m for 5 h on 5 days a week. After adaptation for two months, a conditioned active avoidance reflex was produced in the animals. In the adapted males a tendency was observed for the reflex to be formed more rapidly and for it to be preserved to a much greater degree than in the control animals. In females adapted to hypoxia under similar conditions no changes were observed in the formation and preservation of the reflex.