Dynamic characteristics of heart rate control by the autonomic nervous system in rats.
We estimated the transfer function of autonomic heart rate (HR) control by using random binary sympathetic or vagal nerve stimulation in anaesthetized rats. The transfer function from sympathetic stimulation to HR response approximated a second-order, low-pass filter with a lag time (gain, 4.29 +/- 1.55 beats min(1) Hz(1); natural frequency, 0.07 +/- 0.03 Hz; damping coefficient, 1.96 +/- 0.64; and lag time, 0.73 +/- 0.12 s). The transfer function from vagal stimulation to HR response approximated a first-order, low-pass filter with a lag time (gain, 8.84 +/- 4.51 beats min(1) Hz(1); corner frequency, 0.12 +/- 0.06 Hz; and lag time, 0.12 +/- 0.08 s). These results suggest that the dynamic characteristics of HR control by the autonomic nervous system in rats are similar to those of larger mammals.
Departments of Physical Therapy and Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9174, USA. masaki.mizuno@utsouthwestern.edu
Masaki
M
Mizuno
Toru
T
Kawada
Atsunori
A
Kamiya
Tadayoshi
T
Miyamoto
Shuji
S
Shimizu
Toshiaki
T
Shishido
Scott A
SA
Smith
Masaru
M
Sugimachi
D000818:Animals; D001341:Autonomic Nervous System / Q000502:physiology*; D001794:Blood Pressure; D004558:Electric Stimulation; D005583:Fourier Analysis; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time; D012815:Signal Processing, Computer-Assisted; D013564:Sympathetic Nervous System / Q000502:physiology; D013997:Time Factors; D014630:Vagus Nerve / Q000502:physiology