Regulation of nonstationary cellular dynamics and chaotic respiratory rhythm in vivo.

摘要

An automated system was developed, utilizing nonstationary analysis of heterodyne laser light scattering, to measure CBF;To investigate the involvement of peripheral feedback loops in the rhythmogenesis of normal breathing patterns and to delineate the bronchial and alveolar sites of action responsible for perturbing respiratory rhythm in anesthetized beagles following irritant challenge, chaotic analysis was applied to transpulmonary pressure time series. The analysis revealed that in vagi-intact animals respiratory rhythm conformed to low order deterministic chaotic behavior. Immediately after a predominantly alveolar deposition of histamine (8mg/ml) the rhythm undergoes a sequence of reverse Hopf bifurcations before returning to the normal chaotic pattern. The same response could not be evoked from a predominantly bronchial challenge of the irritant. A bilateral vagotomy, caused the normal respiratory rhythm to become periodic and prevented the occurrence of the bifurcations after the alveolar challenge. (Abstract shortened by UMI.).;The system was then enhanced using a TMS320C30 digital signal processor to yield CBF