[Effect of thyroliberin on membrane potential and pattern of spontaneous activity of neurons of the respiratory center in rats in vitro].

On frontal brainstem slices of rat by means of whole-clamp recordings, we investigated effects of TRH (10(-8) [symbol: see text]) on membrane potential and firing pattern of the neurones in ventrolateral area of the solitary tract nucleus and pre-Botzinger complex. TRH induced a membrane depolarisation and an increase in spontaneous activity of the respiratory centre neurones. After TRH administration, a shortening of time intervals between the beginning of bursts was found in bursting neurones of the pre-Botzinger complex. In some silent neurones, TRH elicited appearance of firing activity, so the silent neurones of the solitary tract nucleus were transformed into tonic while the silent pre-Botzinger complex neurones were transformed into bursting ones. Thus, there is a direct regulatory effect of TRH on the respiratory centre neurones at the level of their membrane.