Central inspiration increases barosensitivity of neurons in rat rostral ventrolateral medulla

T. Miyawaki, P. Pilowsky, Q. J. Sun, J. Minson, S. Suzuki, L. Arnolda, I. Llewellyn-Smith, J. Chalmers

    Research output: Contribution to journalArticle

    66 Citations (Scopus)

    Abstract

    Barosensitive neurons in the rostral ventrolateral medulla (RVLM) often have a respiratory-related modulation of their activity. However, the extent of the interaction between baroreceptor and respiratory inputs is controversial. The main aim of the present study was to determine the effect of central respiratory drive (CRD) on the barosensitivity of RVLM neurons. Extracellular recordings were obtained from 68 barosensitive neurons in the RVLM of anesthetized, paralyzed, and bilaterally vagotomized Sprague-Dawley rats. Examination of phrenic-triggered histograms revealed five activity patterns among barosensitive neurons: inspiratory depression (type I, n = 20), ear]y inspiratory activation (type II, n = 14), postinspiratory activation (type III, n = 18), expiratory depression (type IV, n = 5) and no modulation (type V, n = 11). In most neurons (types I and III and 56% of type II) inhibition produced by aortic nerve stimulation was greater in inspiration than in expiration. Cardiac-related modulation, as an index of natural phasic baroreceptor activation, was also greater in inspiration than expiration in type III neurons. The results demonstrate that CRD modulates the baroreflex at the level of the RVLM.

    Original languageEnglish
    Pages (from-to)R909 - 918
    Number of pages10
    JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
    Volume268
    Issue number4
    Publication statusPublished - Apr 1995

    Keywords

    • aortic nerve
    • blood pressure
    • bulbospinal
    • phrenic
    • respiratory
    • sympathetic

    Fingerprint Dive into the research topics of 'Central inspiration increases barosensitivity of neurons in rat rostral ventrolateral medulla'. Together they form a unique fingerprint.

  • Cite this