Intravenous thyrotropin releasing hormone (TRH) enhances the excitatory actions of acetylcholine (ACh) on rat cortical neurons.

I.v. administered TRH (1.25--10 mg/kg) enhanced the excitatory actions of iontophoretically applied ACh on spontaneously active cerebral cortical neurons of pentobarbital-anaesthetized rats. These observations are consistent with the hypothesis of a cholinergic-link in the anti-anaesthetic actions of exogenously administered TRH.