Bursian A V, Dmitrieva L E, Sizonov V A
Zh Evol Biokhim Fiziol. 2009 Nov-Dec;45(6):553-8.
In wakeful rats at the age from newborn to 3 weeks there were studied interrelations of rhythmical fluctuations of heart rate, respiration rate, and periodic spontaneous motor activity. In all studied systems, these fluctuations are coordinated and occur in several frequency diapasons. Frequencies in the periminute diapason (the period from 30 to 90 s) are the most constant and do not change with age. Regular fluctuations are the most stable in newborns. Bursts of motor activity usually are irregular, but episodically the distinct periminute rhythm is traced. Studies of the character of interaction of the heart activity, respiration, and periodic somatomotor excitation allow stating that the main coordination pathway of spontaneous autorhythmical functions in early postnatal ontogenesis is formation of secondary rhythms. Possible pathway of formation of the secondary rhythms are considered.
