Receptor specificity in various peripheral zones of the interoceptive analyzer

Summary

A solution of 0.01 N HCl was introduced into the lumen of the cat and it was found that there was an increase in the number of afferent impulses from the duodenum, and that a similar increase occurred when 0.1 N HCl was introduced into the jejunum. The increase in the impulses shows a long latent period lasting from 30 seconds to 5 minutes, and the effect is maintained for as long as 30 or even 60 minutes. Introduction of 0.01 N HCl solution into the perfusate provoked a brief increase of rapid onset in the afferent impulses from the jejunum. Reduction of the partial oxygen pressure of the blood or of the perfusate increased the number of impulses from the sinus nerves, but had no such effect on the nerves from the intestine. Therefore, different portions of the peripheral interoceptors show a selective sensitivity to various stimuli.