The pre-Bötzinger complex participates in generating the respiratory effects of thyroliberin

Experiments on anesthetized rats were performed to study the effects of microinjection of thyroliberin (10 fM-100 microM) into the area of the pre-Bötzinger complex on respiratory and circulatory parameters. Thyroliberin dose-dependently increased respiration frequency, with shortening of inspiration and expiration. Tidal volume and the amplitude of the integrated EMG recorded from the inspiratory muscles decreased after administration of concentrated solutions. Using this dosage method, thyroliberin had weak effects on systemic hemodynamics. The data suggest that structures located in the area of the pre-Bötzinger complex take part in generating the respiratory effects of thyroliberin.