The effect of the stress reaction on higher nervous activity

Research paper by N. A. Nikolov

Indexed on: 01 Nov '63Published on: 01 Nov '63Published in: Bulletin of Experimental Biology and Medicine


Experiments with conditioned reflexes were carried out on 4 dogs. As established, stress reaction resulting from injection of formalin (2 ml of 10% solution) into the right fore-paw causes many changes in the higher nervous activity. During the first day they are manifested in a marked (up to a total) inhibition in the cortex and subcortex and eosinophil count reduction by more than 50%—the phase of shock. A phase of countershock develops within the next 3 dats, merging with the stage of resistance. The nervous system becomes inhibited again at the stage of exhaustion. The 4th stage, or the restitution stage, is described as well. In stress reaction the excitatory process in the brain cortex suffers more than in subcortical nervous formations. This is explained by the greater resistance of the latter to strong stimuli formed during the phylogenesis.