Optimal amount of oxygen is crucial for maintaining normal brain function. The lack of this essential molecule promotes hypoxia. Fetal hypoxia leads to a decrease in adaptive potential of the brain and plasticity due to a disturbance in neuronal networking, especially in the cortex and hippocampus. Brain damage can lead to serious consequences such as mental retardation, cerebral palsy, memory disturbances and epilepsy. Rats, the most common animal models of hypoxia, provide a better understanding of the less laboratory-accessible human brain. The stage of brain development of neonatal rats corresponds to the stage of development of a human fetal brain from 23rd to 34th week of pregnancy. The aim of this graduation thesis is to determine whether there are changes in social, emotional and exploratory behaviour, as well as locomotion and cognition in adult rats exposed to hypobaric or normobaric conditions on the first postnatal day compared to adult rats in control group and to what extent they correspond to changes observed in young rats. The differences in locomotion and exploratory behaviour observed in the group of young hypoxic rats in relation to the control group were not retained in adulthood. The only significant difference remaining in adulthood was the increased number of rearings in the experimental groups, which may be related to memory and spatial processing mediated by dopamine. The results suggest that some behavioural changes, caused by the exposure of developing brain to hypoxia, compensate themseves during development, while others remain permanently present.