A dp/dt method to assess dynamic properties of lung mechanoreceptors

The activity of airway slowly adapting mechanoreceptors (SARs) reflects the presence of both a static and dynamic component. The dynamic response is typically assessed by the adaptation index; however, this is an indirect reflection of the more appropriate physiological stimulus, the rate of change of inflation pressure (dp/dt). We describe a method in which measurement of receptor discharge exceeding the SAR static response is used to measure dynamic discharge and dynamic sensitivity of lung mechanoreceptors. Repeat inflations with varying dp/dt illustrate the method for a SAR in which the dynamic sensitivity is inversely related to dp/dt and the initial "onset" discharge is highly dp/dt sensitive. The method may provide new insight into the classification and behaviour of lung mechanoreceptors.