Influence of postnatal hypoxia on learning and memory formation of adult rats

Male Wistar rats were exposed to a single normobaric hypoxic treatment at the age of either 15 or 20 days. Two different kinds of hypoxia were used: 4% O2 for 6 h or 3.5% O2 for 40 min. At the age of 8 weeks the acquisition and retention of a brightness discrimination was investigated in all animals. The acquisition of all treated animals did not differ from the corresponding controls. Both hypoxic treatments at the 20th day resulted in a significant improvement of retention in the adult age, whereas only hypoxia with 3.5% O2 for 40 min at the 15th day showed a similar effect, the treatment with 4% O2 for 6 h at this time was ineffective.