Lateralized Response of the Hypoglossal, Facial and Phrenic Nerves to Lung Inflation

Abstract

For several animal species it is well known that, after the lungs are prevented from collapsing at the end of inspiration or while they are inflated by positive pressure, pattern of breathing markedly changes — inspiratory activity diminishes and expiratory time increases. Magnitude of these changes rises with increasing tidal volume. Volume of air in the lungs is sensed by the slowly adapting pulmonary stretch receptors (PSR). The information arising from each lung is transmitted to the brainstem solely via the vagus nerve ipsilateral to the lung (Guz et al., 1966; Cross et al., 1981). It is not known how volume information arising from each lung individually and reaching the brainstem by two separate afferent pathways summates and converges onto a common output. The aim of this study was to assess whether, after lateralization of the PSR inputs by denervation of one lung, activity of respiratory nerves on both sides of the body will be equally inhibited during maintained lung inflation or whether lateralized input will result in a lateralized response.