The Ultrastructure of Cutaneous Receptors in the Skin of Caiman Crocodilus

Abstract

The main preceding studies on the innervation of reptile skin are those by Hulanicka (1913) and Jaburek (1927). The touch papilla described by the light microscope are spot-like elevations scattered over the horny scales of the upper and lower jaws of the Caiman crocodilus. The diameter of such a touch papilla measures 0,3–0,5 mm (Fig. 1). In the living animal the surface epithelium of the papilla is tightly stretched. Near the papilla the horny part of the epithelium is smaller than over the surrounding area. It is the purpose of this paper to describe the ultrastructure and organization of different types of nerve terminals, such as intraepidermal nerve terminals, a subepithelial Merkel cell-neurite complex, lamellated free receptors and lamellated encapsulated receptors with a capsule space.

Supported by Deutsche Forschungsgemeinschaft SFB 114 and Schwerpunktprogramm “Rezeptorphysiologie”.