[QUANTITATIVE ASSESSMENT OF THE RELATIONSHIP BETWEEN SLOW-WAVE OSCILLATIONS OF HEART RHYTHM AND MOTOR ACTIVITY IN RAT FETUSES WITH FEMALE RESPIRATORY AND CARDIAC ACTIVITY].

A mathematical analysis of correlation of slow-wave processes in the system > during the last 4 days of bearing was performed in experiments on rat fetuses with retained placental connection with the female. The parallel recording of physiological indicators of the female and fetus state revealed the existence of a relationship between oscillations of heartbeat rhythms and breathing in about-one-minute and many-minute ranges. The highest values of connection between the heart rhythms of female and fetus are characteristic for days 17 and 20 of gestation. On day 18-19 the interrelationships are slightly weaker. The specific mechanism providing this synchronization between heartbeat oscillations of mother and fetus is unclear. There are two hypothetic possibilities: an oscillation driver close in parameters for mother and fetus, and the maternal rhythm directly affecting the fetus.