Effect of electrical stimulation of vagus nerves on cardiac activity in sympathectomized rats during postnatal ontogeny.

In intact rats vagal stimulation reduced heart rate, but had no effect on stroke volume. In sympathectomized animals this treatment decreased both the heart rate and stroke volume. Sympathectomized rats displayed higher sensitivity to vagal nerve stimulation compared to intact animals of the same age (except for rats aging 21 and 56 days).