EN
The reaction to stress stimuli occurs at the mental and somatic level, and it is why the behavioral changes may be a good predictor for assessment of such states. Many studies show that the age of animal influences the adaptation abilities to a significant level. The aim of the study was to compare adaptation processes in response to short-lasting stressors by the analysis of behavior of young (2-month-old) and mature (12-month-old) rats. The experiment was performed on 60 rats which were treated with the following stressors: food deprivation, water deprivation, isolation and bacterial lipopolysaccharide (LPS) injection. Then the behavioral tests of „open field“ and „eight arms“ were performed. The obtained results showed significant decrease of the activity of mature rats in comparison to young ones in both behavioral tests, especially in response to water deprivation („open field“) and isolation („eight arms“). Only in the group treated with LPS young rats showed lower activity, however, in this group the lowest activity was seen on both age groups. Animals showed significant decrease of motor activity. Higher activity of mature rats in response to LPS treatment may be due to the higher resistance to pyrogen and the lower energy demand to fight the inflammation.