[Neurohistologic and histochemical findings concerning the accessory fiber of several incapsulated receptors].

In order to clarify the role of catecholamines in encapsulated receptors, Pacinian corpuscles and the bulbs of Krause have been studied by the fluorescent method of Falck. Fluorescence, specific for catecholamines, has not been revealed in the receptors. Catecholamines do not seem to be neuromediators in stimulating sensitive nerve terminals. The regulatory role of catecholamines in the activity of the encapsulated receptors is discussed. The neurohistological method of tissue fixation in the mixture of zink-iodine -- osmic acid has revealed some additional nerve fibers (Timofeev's apparatus) in the bulbs of Krause of the cat lip and nose. In order to understand the nature of the additional fibres in the bulbs of Krause, a branch of the trigeminal nerve has been sectioned in the suborbital area. After sectioning the staining of both the main and additional fibres in the bulbs of Krause in the lip and nose has disappeared. The data obtained support the view on sensitive nature of the additional fibres (Timofeev's apparatus) in the sensitive bulbs of Krause.