Sensory innervation in the rim of the octopus sucker

Abstract

Anatomical components of afferent innervation in the rim of the octopus sucker are described. In the sensory epithelium under the smooth cuticle two associated ciliated receptor cell-types (presumably chemosensitive) occur in clusters. A third ciliated receptor cell-type under the toothed cuticle may be a mechanoreceptor. A non-ciliated receptor cell-type of unknown function, under the toothed culticle, is characterized by a microvillus-lined apical canal containing dense granular material. The axons of the latter two receptors go directly into large nerve tracts which run through the infundibular muscle and on to the ganglion of the sucker. The axons of the first cell-types terminated on interneurons either in the base of the epithelium or below the epithelium. All the interneurons of the basal region of the epithelium migrate centripetally and develop into encapsulated interneurons. Within the epithelium, fine fibers provide collateral contact among cluster receptors. Collateral interaction among basal and encapsulated interneurons occur in the infundibular plexus. The microanatomy of the rim of the sucker suggests that chemosensory cues are funneled into the interneurons where they are concentrated into integrated signals, while other sensory input is probably sent directly to the ganglia of the sucker and/or arm.

Nitric oxide synthase (NOS) in the brain of the cephalopod Sepia officinalis

“…In Sepia, too, there are chemoreceptors in the suckers, although far fewer (Graziadei, 1964;Graziadei and Gagne, 1976). Nevertheless, clear positive staining can be seen in the cuttlefish sucker epithelium, especially around the rim of suckers (Fig.…”

Active marine predators: The sensory world of cephalopods

“…The receptors involved in contact chemoreception occur in the distal region of the long digital tentacles of Nautilus (Bidder, 1962;Fukuda, 1980Fukuda, , 1987 and in the lips and suckers of octopuses, cuttlefishes and squids ( Figure 8B; Graziadei, 1962Graziadei, ,1964aGraziadei, ,b, 1965aWells etal, 1965;Emery, 1975a,b;Santi, 1975;Graziadei and Gagne, 1976b). There are about 10,000 chemoreceptor cells in a sucker of an octopod (a total of 16 million cells per animal), but only about 100 such cells are present in a sucker of a cuttlefish (Graziadei, 1964a,b).…”

Role of olfaction in Octopus vulgaris reproduction

“…In coleoid cephalopods there are three known chemical sensory epithelia: buccal lips (Emery, 1975), arm suckers (Graziadei and Gagne, 1976), and olfactory organs (Zemoff, 1869). The function of sensory epithelia in the buccal lips and arm suckers has been well studied and shows capabilities for both tactile and distance chemoreception (Hanlon and Messenger, 1998).…”