Activation of sympathetic vasodilator and vasoconstrictor neurons by electric stimulation in the medulla of the dog and cat.

Electric stimulation in the ventrolateral area of the medulla elicited vasodilation in skeletal muscles, and vasoconstriction in the skin and intestines. The vasodilation was accredited to activity in the cholinergic sympathetic vasodilator outflow previously shown to originate in the motor cortex of the dog. The possible functional significance of the vasodilator fibers in regulating muscle blood flow during exercise is discussed.