Respiratory response on the activation of GABAа-and GABAb-receptors of a parafacial respiratory group by specific agonists

The purpose of the paper is to conduct comparative analysis of GABAA and GABAВ receptors of the parafacial respiratory group (pFRG) in central mechanisms of respiratory regulation in adult rats. Materials and Methods. The authors studied the reactions of external respiration and diaphragmatic muscle on microinjections of muscimol and baclofen solutions (10-6 M, 200 nl) in the region of pFRG on rats, anesthetized with urethane. Injections were administered through a glass microcannula according to stereotactic coordinates. A spirogram and electromyogram (EMG) of the diaphragm were recorded in the initial state and within 60 minutes after microinjection of the abovementioned agonists of GABAA and GABAВ receptors. Results. Microinjections of muscimol, the agonist of GABAA receptors, in pFRG had an inhibitory effect on respiration. The inhibitory effect was characterized by a short latent period. Minute lung ventilation decreased in rats due to changes in tidal volume and respiratory rate, while the inspiratory and expiratory time increased...