Autonomic effects of hypothalamic self-stimulation in the cat

Respiration, heart rate and arterial blood pressure were recorded continuously during self-stimulation with systematically varied stimulus parameters. Conspicuous autonomic effects were induced by self-stimulation. Acceleration in the respiration and heart rate, and rise in the arterial blood pressure were generally obtained as direct effects of the stimulus train, which were followed by remarkable rebound-like aftereffects. A close relationship was found between the lever-pressing behaviour and the peripheral autonomic effects of self-stimulation. The frequency of self-stimulation increased in parellel with the amplitude of the autonomic responses to a certain level, and the animal stopped self-stimulation whenever the amplitude of the autonomic effects exceeded this level. The results are consistent with the idea that the periopheral autonomic changes can modulate self-stimulation.