Open AccessAging attenuates the vestibulorespiratory reflex in humans
Author(s) -
Nathan T. Kuipers,
Charity L. Sauder,
Chester A. Ray
Publication year - 2003
Publication title -
journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2002.033357
Subject(s) - reflex , vestibular system , ventilation (architecture) , stimulation , vestibulo–ocular reflex , audiology , medicine , otolith , breathing , anesthesia , biology , physics , fishery , fish <actinopterygii> , thermodynamics
Activation of the vestibular system changes ventilation in humans. The purpose of the present study was to investigate whether aging alters the vestibulorespiratory reflex in humans. Because aging attenuates the vestibulosympathetic reflex, it was hypothesized that aging would attenuate the vestibulorespiratory reflex. Changes in ventilation during engagement of the semicircular canals and/or the otolith organs were measured in fourteen young (26 +/- 1 years) and twelve older subjects (66 +/- 1 years). In young subjects, natural engagement of the semicircular canals and the otolith organs by head rotation increased breathing frequency during dynamic upright pitch at 0.25 Hz (15 cycles min-1) and 0.5 Hz (30 cycles min-1) (delta2 +/- 1 and delta4 +/- 1 breaths min-1, respectively; P < 0.05) and during dynamic upright roll (delta2 +/- 1 and delta4 +/- 1, respectively; P < 0.05). In older subjects, the only significant changes in breathing frequency occurred during dynamic pitch and roll at 0.5 Hz (delta2 +/- 1 and delta2 +/- 1 for pitch and roll, respectively). Stimulation of the horizontal semicircular canals by yaw rotation increased minute ventilation in young but not older subjects. Selective engagement of the otolith organs during static head-down rotation did not alter breathing frequency in either the young or older subjects. The results of this study indicate that the vestibulorespiratory reflex is attenuated in older humans, with greater vestibular stimulation needed to activate the reflex.