Correlated effects of clonidine on single-neuron activities in the gigantocellular reticular nucleus, arterial pressure and heart rate in the cat.

In chloralose-urethane anesthetized cats, intravenous administration of clonidine (10 micrograms/kg) promoted an increase in single-neuron discharges in the gigantocellular reticular nucleus that exhibited a degree and time-course parallel to the hypotension and bradycardia produced by the imidazoline compound. This observation was taken to be a positive indication that clonidine may pharmacologically activate (or disinhibit) neurons in this reticular nucleus, which in turn elicits vasodepression and cardioinhibition.