[Cortical influences on hemodynamics during combined nociceptive stimulation and electric stimulation of septal and bulbar brain structures]

Abstract

Changes of the arterial pressure, blood flow volume rate and peripheral vascular resistance were studied under the nociceptive and electric stimulation of the microcellular reticular nucleus of the medulla oblongata and the lateral septal nucleus in cats. The isolated nociceptive stimulation of the reticular nucleus increased the arterial pressure and the peripheral vascular resistance whereas the stimulation of the septum induced a depressor reaction. The combined stimulation of the bulbar structures increased still more the peripheral vascular resistance. The change in the pressor reaction depended on the character of the previous stimulation. The combined stimulation of the septum completely abolished the pressor nociceptive reaction. The reaction was but decreased under the reverse combination of the electric and nociceptive stimuli. Application of strychnine and potassium chloride on the sensomotor cortical area induced a clear decrease in the pressor reaction only when the reticular nucleus had been stimulated. The peripheral vascular resistance decreased after the application of these agents as well as on the stimulation of the septum.