[Effect of stimulation of the central gray substance of the midbrain on hemodynamic nociceptive reactions].

Experiments on unrestrained rats were made to study the influence of central gray matter of the midbrain, whose activation evokes analgesia, on hemodynamic manifestations of pain reactions under tooth pulp irritation. Electrical stimulation of the brain "analgetic areas" that does not change the animals' behavior or vegetative indices at rest decreased or abolished nociceptive arterial pressure reactions and tachycardia. Possible mechanisms of central gray matter of the midbrain influence on the pain-evoked vegetative reactions are discussed.