Adaptation of Cutaneous Tactile Receptors. Iii by Hudson Hoagland

In a recent paper (Hoagland, 1934-35) evidence was presented indicating that adaptation to pressure as measured by the failure of nerve impulses from single mechanoreceptors in frogs' skin is produced by an inhibitory neurohumor, probably containing potassium, released from cutaneous cells when they are pressed upon. The receptors are axon endings branching among the cutaneous cells. The released potassium was assumed to raise the concentration of potassium, K o, outside of the axon branches, and thus to reduce their excitabilities by lowering the ratio of potassium inside the nerve to that outside (K dKo).