Age Changes in Patterns of Exploratory Behavior and Processes of Lipid Peroxidation of Female Rats Depending on the Stage of the Reproductive Cycle

The paper presents the results of a study of patterns of exploratory behavior and processes of lipid peroxidation in liver tissue in young and old female rats, depending on the stage of the estrous cycle. The studies were carried out on females in the estrus and diestrus stages. It was shown that females at the age of 2-3 months were characterized by regular reproductive cycles with an average duration of 4.5 ± 0.11 days, which corresponds to the normal estrous cycle of sexually mature rats, which includes 4 consecutive stages. Animals 24 months old had cycles different from the normal physiological cycles of young animals. The work shows that in young sexually mature females the motor activity in the open field test is higher, and the level of anxiety is lower in the estrus stage compared to the analogous indicators in the diestrus stage. In young females, the baseline MDA level was significantly higher in the diestrus stage relative to that in the estrus stage. Patterns of exploratory behavior and the level of LPO depended on the age of the animal. Old rats had an increased level of anxiety regardless of the stage of the reproductive cycle, while young females were characterized by higher patterns of exploratory activity. In addition, old female rats had a higher level of free radical oxidation in comparison with young animals.