Cell junctions with funnels in the olfactory mucosa of frogs (Rana temporaria L.).

A characteristic structure in the apical junctional belt of the olfactory epithelium in Rana temporaria is visible in freeze-fracture preparations. This structure is described as a "funnel with channel across the junctional belt". It is supposed to represent a possible way for "discarding used molecules" after stimulation, and to allow the stimulation of free nerve endings in the depth of olfactory epithelia.