THE DISTRIBUTION OF CHOLINESTERASE IN THE CUTANEOUS RECEPTOR ORGANS, ESPECIALLY TOUCH CORPUSCLES OF THE HUMAN FINGER

Abstract

1. Cutaneous receptor organs of the human digital skin have been investigated for cholinesterase activity by a modification of the histochemical technique of Koelle and Friedenwald, and the findings have been analyzed in relation to the structure of the receptors. 2. It was found that in Meissner's corpuscles the nerves and their sheaths were negative, but the plasma membranes of the laminar cells and the intercellular substance gave strong positive reactions with either acetyl or butyryl substrates. 3. In Merkel's corpuscles, nerve endings and the associated Merkel's cells were negative, but the preterminal medullated nerve fibres gave positive reactions with the butyryl substrate. 4. In hairs, the terminal nerve fibres surrounding the epithelial sheaths gave positive reactions with both substrates. 5. Free nerve endings were negative but the cells related to the endings gave a positive reaction with both substrates. 6. Capillaries and sebaceous glands were negative, but adventitia of larger blood vessels gave positive reactions with the butyryl substrate. 7. The significance of the findings is discussed and a suggestion is made that both acetylcholine and its enzyme may constitute active agents in the synaptic transmission of a nervous impulse in Meissner's corpuscle.