OBJECTIVE

To study the psycho-emotional state and its relationship to the duration of ultrasonic vocalization in the offspring of rats with physiological and stress-complicated pregnancy.

MATERIAL AND METHODS

The experiments were performed on the offspring (n=120) of rats with physiological pregnancy and the offspring of animals stressed during the entire gestation period (21—23 days). Study animals were divided into the following groups: 1 — intact — males and females (n=52) born to healthy rats; 2 — stress — males and females (n=68) born to rats that underwent stress during pregnancy.

At the age of 17 days, the total vocalization duration (at 50 kHz) was recorded in rats. To assess the psycho-emotional state of the offspring, the open field and elevated plus maze tests were performed at 22 days, marble burying at 35 days, and Porsolt forced swimming test at 47 days. To assess cognitive function in the offspring, short-term working memory was examined in the recognition of a new object test at 35 days and long-term memory in the conditioned passive avoidance reflex test at the age of 47 days.

RESULTS

The results of the open field and elevated plus maze tests indicated that the offspring of females stressed during pregnancy showed anxious behavior. In addition, animals from stressed rats exhibited compulsive and depressive behaviors in the marble burying and Porsolt forced swimming tests. The offspring of stressed rats showed impaired reproduction of the memory traces in the conditioned passive avoidance reflex test.

CONCLUSION

In the offspring of females stressed during pregnancy, anxious, compulsive, and depressive behavior is observed, accompanied by an increase in the duration of ultrasonic vocalization at 50 kHz.