Modulation of Vagal Afferent Stimulation on High Frequency Oscillation in Phrenic Nerve / 第二军医大学学报

ABSTRACT

To evaluate the role of the vagal afferents in the generation and formation of high frequency oscillation (HFO), effect of selective electrical stimulation of A?-? afferent fiber groups of the vagus nerve (0.4-0.5 V, 0.1ms, 5-160 Hz), applied at three respiratory phases inspiratory phase (IS), expiratory phase (ES), and continuous phase throughout both IS and ES (CS), on the phrenic HFO was quantitatively assessed on ether-anesthetized, vagotomized, paralyzed and artificially ventilated rabbits. After calculation of the power spectrum of the efferent phrenic nerve activity, the mean square values (MSV), representing total amount of HFO-output, and the peak frequency of the HFO were estimated by means of curve-fitting method. Regardless of the mode of the stimulation, the MSV decreased in a stimulus-frequency dependent fashion. The CS was most potent, then IS, and ES was less effective, though the reduction was significant (p