Attenuation of A Pulsatile Pressure Component in the Neural ARC of the Arterial Baroreflex
NATIONAL CARDIOVASCULAR CENTER RESEARCHINST SUITA (JAPAN) DEPT OF CARDIOVASCULAR DYNAMICS
Pagination or Media Count:
A transfer function from baroreceptor pressure input to sympathetic nerve activity SNA shows high-pass characteristics in the frequency range from 0.01 to 1 Hz in anesthetized rabbits. The high-pass characteristics of the neural arc contribute to a quick and stable arterial pressure AP regulation. However, if the high-pass characteristics hold up to the frequency of heart rate 3-5 Hz, a pulsatile pressure component in AP would yield an extremely large amplitude of pulsatility in SNA. Such a large amplitude in SNA would hit the nonlinearities in baroreflex pathways, thereby disable the baroreflex regulation of AP. We hypothesized therefore that the transfer gain at the frequency of heart rate would be much smaller than that predicted from the high-pass characteristics of the neural arc. In anesthetized rabbits n6, we perturbed carotid sinus pressure CSP according to a binary white noise with a switching interval of 50 ms.
- Anatomy and Physiology
- Medicine and Medical Research