Changes in ganglion nodosum neurons associated with stress-related cardiac deficiency.

Cell bodies of cardio-vascular receptors localized in the ganglion nodosum of rabbits exposed to experimental emotional stress were studied with the light and electron microscope and histochemically. Under emotional stress some rabbits demonstrated almost unchanged arterial pressure and only a small increase in heart rate, while other animals displayed strongly marked disturbances of their blood circulation leading to the acute heart deficiency at the end of the experiment. In the stress-resistant rabbits, microscopic anatomy and ultrastructure of neurons indicated their increased activity. Activities of lysosomal enzymes--acid phosphatase and aminopeptidase--were found to be at the control level, while the activity of mitochondrial enzyme--glutamate dehydrogenase--was slightly increased. On the other hand morphological evidence of severe hyperactivity and exhaustion was revealed in neurons of the stress-predisposed rabbits. Moreover the activities of all three enzymes studied were significantly increased. These results indicate correlation between the structural and metabolic changes occurring under experimental emotional stress in nodosal neurons and the extent of hemodynamic changes.