Role of the Betzinger complex GABA A-receptors in respiratory control in rats

In adult anaesthetized rats the reactions of breathing and inspiratory muscles activity to microinjections of muscimol (10 -6 M) andbicuculline (10 -6 M) into the Betzinger complex (BC) were investigated. It was shown, that muscimol microinjections into the BC shortened inspiratory and expiratory time and increased respiratory frequency, under this conditions the tidal volume and lung ventilation were increased. These responses corresponded to responses of temporal and amplitude parameters of electromiogramms of inspiratory muscles activity. Аdministrations of bicuculline into the BC decreased respiratory frequency, while volumetric parameters of breathing was not changed essentially. It is suggested that the reactions observed demonstrate the various contribution of GABA A-receptors within BC, in control of the temporal and volumetric parameters of breathing pattern.