Brainstem loci for activation of electrodermal response in the cat

Brainstem loci from which electrodermal responses could be elicited were systematically explored by direct-stimulation techniques in chloralose-anesthetized and decerebrate cats. Reactive sites of the greatest amplitude were found to extend from the rostral border of the posterior hypothalamus, through the ventrolateral reticular formation of the pons and the medulla, to the cervical cord. Stimulation of these sites elicited stable, reproducible electrodermal responses of 10-30 mV in amplitude. In addition, it was found that stimulation of the ventrolateral extent of the lower brainstem evoked similar responses in the decerebrate preparation. Electrodermal responses could not be elicited from the dorsal medulla, the posterior commissure, or the midline region. The electrodermal response could be elicited from an apparently hypothalamus through the ventrolateral brainstem.