Prefrontal control of respiration.

The aim of the present study was to test the hypothesis that different parts of the prefrontal cortex could be involved in respiratory control. This hypothesis was tested by examining the changes in respiratory pattern produced by low intensity electrical stimulation of the insular and infralimbic cortex. The experiments were performed on the anaesthetised rats. It was found that the sites capable of inducing different kinds of respiratory responses were localized to the insular and infralimbic cortices. Microstimulation of the anterior insular cortex produced responses which manifested themselves in a decrease of inspiratory flow and tidal volume, but the respiratory time remained stable. Responsive sites within caudal insular and infralimbic cortex produced other alterations in breathing which included an increase of inspiratory flow, and decreases of tidal volume and respiratory time. These observations support the hypothesis proposed and localize distinct patterns of respiratory responses to different parts of the prefrontal cortex in the rat.