On the humoral transfer of excitation from one neuron to another

The idea of ​​the possibility of transferring nervous excitation by humoral means was first expressed by Langley. His suggestion was related to vasodilation caused by irritation of sensory fibers. Several years later, this assumption was confirmed experimentally. H. Dale and J. Gaddum have established in their experiments that both the vasodilation resulting from irritation of sensory fibers and parasympathetic nerves, and the contractures of denervated muscles accompanying this action, are very similar to the vasodilation and contractures caused by acetylcholine. This gives reason with a high probability to assume. That this vasodilating effect of sensitive fibers. The “antidromic” conductive, and parasympathetic nerves are due to the peripheral release of acetylcholine. We also came to the conclusion about the humoral transfer of the vasodilating action of sensory fibers in our previous work, where we showed that when the posterior sensory roots are irritated, the blood of the corresponding limb acquires vasodilating properties. The same properties are acquired by Ringer's solution, passed through the vessels of the extremities, when the posterior sensitive roots are irritated.