Central inspiratory influence on abdominal expiratory nerve activity

Ralph F Fregosi, D. Bartlett

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Our purpose was to determine whether the intensity of abdominal expiratory nerve discharge is conditioned by the intensity of the preceding inspiratory phrenic discharge, independent of mechanical and chemical afferent influences. In decerebrate, paralyzed, vagotomized cats with bilateral pneumothoraxes, we recorded phrenic and abdominal (cranial iliohypogastric nerve, L1) nerve activities at hyperoxic normocapnia. We reduced the duration and intensity (i.e., integrated peak height) of phrenic nerve discharge for single cycles by stimulating the cut central end of the superior laryngeal nerve (SLN) during the central inspiratory phase (75 μA, 20-50 Hz, 0.2-ms pulse). Premature termination of inspiration consistently reduced expiratory duration (TE) and abdominal expiratory nerve activity (area of integrated neurogram), but the average reduction in TE was much less than the reduction in abdominal nerve activity (14 vs. 51%). Stimulation of the cut central end of the vagus nerve yielded similar results, as did spontaneous premature terminations of inspiration, whcih we observed in one cat. SLN stimulation during hyperoxic hypercapnia resulted in more variable responses, and higher stimulation frequencies were usually required to abort inspiration. SLN (or vagal) stimulation during expiration consistently increased abdominal expiratory nerve activity. We speculate that this facilitatory response is gated during inspiration, thereby allowing the inspiratory conditioning effect on the subsequent expiration to be expressed. These findings indicate that information concerning cycle-to-cycle changes in the intensity of centrally generated inspiratory activity is conveyed to abdominal expiratory motoneurons, leading to corresponding changes in their activity.

Original languageEnglish (US)
Pages (from-to)1647-1654
Number of pages8
JournalJournal of Applied Physiology
Volume65
Issue number4
StatePublished - 1988
Externally publishedYes

Fingerprint

Laryngeal Nerves
Diaphragm
Cats
Phrenic Nerve
Vagus Nerve
Hypercapnia
Cranial Nerves
Motor Neurons
Pneumothorax

ASJC Scopus subject areas

  • Endocrinology
  • Physiology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Central inspiratory influence on abdominal expiratory nerve activity. / Fregosi, Ralph F; Bartlett, D.

In: Journal of Applied Physiology, Vol. 65, No. 4, 1988, p. 1647-1654.

Research output: Contribution to journalArticle

@article{82ad64cd50174f30a8013a1ca85c8da9,
title = "Central inspiratory influence on abdominal expiratory nerve activity",
abstract = "Our purpose was to determine whether the intensity of abdominal expiratory nerve discharge is conditioned by the intensity of the preceding inspiratory phrenic discharge, independent of mechanical and chemical afferent influences. In decerebrate, paralyzed, vagotomized cats with bilateral pneumothoraxes, we recorded phrenic and abdominal (cranial iliohypogastric nerve, L1) nerve activities at hyperoxic normocapnia. We reduced the duration and intensity (i.e., integrated peak height) of phrenic nerve discharge for single cycles by stimulating the cut central end of the superior laryngeal nerve (SLN) during the central inspiratory phase (75 μA, 20-50 Hz, 0.2-ms pulse). Premature termination of inspiration consistently reduced expiratory duration (TE) and abdominal expiratory nerve activity (area of integrated neurogram), but the average reduction in TE was much less than the reduction in abdominal nerve activity (14 vs. 51{\%}). Stimulation of the cut central end of the vagus nerve yielded similar results, as did spontaneous premature terminations of inspiration, whcih we observed in one cat. SLN stimulation during hyperoxic hypercapnia resulted in more variable responses, and higher stimulation frequencies were usually required to abort inspiration. SLN (or vagal) stimulation during expiration consistently increased abdominal expiratory nerve activity. We speculate that this facilitatory response is gated during inspiration, thereby allowing the inspiratory conditioning effect on the subsequent expiration to be expressed. These findings indicate that information concerning cycle-to-cycle changes in the intensity of centrally generated inspiratory activity is conveyed to abdominal expiratory motoneurons, leading to corresponding changes in their activity.",
author = "Fregosi, {Ralph F} and D. Bartlett",
year = "1988",
language = "English (US)",
volume = "65",
pages = "1647--1654",
journal = "Journal of Applied Physiology",
issn = "8750-7587",
publisher = "American Physiological Society",
number = "4",

}

TY - JOUR

T1 - Central inspiratory influence on abdominal expiratory nerve activity

AU - Fregosi, Ralph F

AU - Bartlett, D.

PY - 1988

Y1 - 1988

N2 - Our purpose was to determine whether the intensity of abdominal expiratory nerve discharge is conditioned by the intensity of the preceding inspiratory phrenic discharge, independent of mechanical and chemical afferent influences. In decerebrate, paralyzed, vagotomized cats with bilateral pneumothoraxes, we recorded phrenic and abdominal (cranial iliohypogastric nerve, L1) nerve activities at hyperoxic normocapnia. We reduced the duration and intensity (i.e., integrated peak height) of phrenic nerve discharge for single cycles by stimulating the cut central end of the superior laryngeal nerve (SLN) during the central inspiratory phase (75 μA, 20-50 Hz, 0.2-ms pulse). Premature termination of inspiration consistently reduced expiratory duration (TE) and abdominal expiratory nerve activity (area of integrated neurogram), but the average reduction in TE was much less than the reduction in abdominal nerve activity (14 vs. 51%). Stimulation of the cut central end of the vagus nerve yielded similar results, as did spontaneous premature terminations of inspiration, whcih we observed in one cat. SLN stimulation during hyperoxic hypercapnia resulted in more variable responses, and higher stimulation frequencies were usually required to abort inspiration. SLN (or vagal) stimulation during expiration consistently increased abdominal expiratory nerve activity. We speculate that this facilitatory response is gated during inspiration, thereby allowing the inspiratory conditioning effect on the subsequent expiration to be expressed. These findings indicate that information concerning cycle-to-cycle changes in the intensity of centrally generated inspiratory activity is conveyed to abdominal expiratory motoneurons, leading to corresponding changes in their activity.

AB - Our purpose was to determine whether the intensity of abdominal expiratory nerve discharge is conditioned by the intensity of the preceding inspiratory phrenic discharge, independent of mechanical and chemical afferent influences. In decerebrate, paralyzed, vagotomized cats with bilateral pneumothoraxes, we recorded phrenic and abdominal (cranial iliohypogastric nerve, L1) nerve activities at hyperoxic normocapnia. We reduced the duration and intensity (i.e., integrated peak height) of phrenic nerve discharge for single cycles by stimulating the cut central end of the superior laryngeal nerve (SLN) during the central inspiratory phase (75 μA, 20-50 Hz, 0.2-ms pulse). Premature termination of inspiration consistently reduced expiratory duration (TE) and abdominal expiratory nerve activity (area of integrated neurogram), but the average reduction in TE was much less than the reduction in abdominal nerve activity (14 vs. 51%). Stimulation of the cut central end of the vagus nerve yielded similar results, as did spontaneous premature terminations of inspiration, whcih we observed in one cat. SLN stimulation during hyperoxic hypercapnia resulted in more variable responses, and higher stimulation frequencies were usually required to abort inspiration. SLN (or vagal) stimulation during expiration consistently increased abdominal expiratory nerve activity. We speculate that this facilitatory response is gated during inspiration, thereby allowing the inspiratory conditioning effect on the subsequent expiration to be expressed. These findings indicate that information concerning cycle-to-cycle changes in the intensity of centrally generated inspiratory activity is conveyed to abdominal expiratory motoneurons, leading to corresponding changes in their activity.

UR - http://www.scopus.com/inward/record.url?scp=0023715958&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023715958&partnerID=8YFLogxK

M3 - Article

C2 - 2972674

AN - SCOPUS:0023715958

VL - 65

SP - 1647

EP - 1654

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

SN - 8750-7587

IS - 4

ER -