Olfactory organ ofOctopus vulgaris: morphology, plasticity, turnover and sensory characterization

Abstract

The cephalopod olfactory organ was described for the first time in 1844 by von Kölliker, who was attracted to the pair of small pits of ciliated cells on each side of the head, below the eyes close to the mantle edge, in both octopuses and squids. Several functional studies have been conducted on decapods but very little is known about octopods. The morphology of the octopus olfactory system has been studied, but only to a limited extent on post-hatching specimens, and the only paper on adult octopus gives a minimal description of the olfactory organ. Here, we describe the detailed morphology of young male and female Octopus vulgaris olfactory epithelium, and using a combination of classical morphology and 3D reconstruction techniques, we propose a new classification for O. vulgaris olfactory sensory neurons. Furthermore, using specific markers such as olfactory marker protein (OMP) and proliferating cell nuclear antigen (PCNA) we have been able to identify and differentially localize both mature olfactory sensory neurons and olfactory sensory neurons involved in epithelium turnover. Taken together, our data suggest that the O. vulgaris olfactory organ is extremely plastic, capable of changing its shape and also proliferating its cells in older specimens.

Enriched Environment Increases PCNA and PARP1 Levels in Octopus vulgaris Central Nervous System: First Evidence of Adult Neurogenesis in Lophotrochozoa

“…(, ). It receives fibers from the olfactory organ, through the olfactory nerve (Young, ), and may act as a switch between growth and reproduction (Di Cosmo and Polese ; Polese et al., , ).…”

“…The olfactory lobe consists of three lobules, anterior, middle, and posterior, interconnected to each other (Young,'71). Its role is recently clarified by Polese et al (2015Polese et al ( , 2016. It receives fibers from the olfactory organ, through the olfactory nerve (Young,'71), and may act as a switch between growth and reproduction Polese et al, 2015Polese et al, , 2016.…”

Biochemical and histopathological impacts of rutile and anatase (TiO2 forms) in Mytilus galloprovincialis

“…After this process, a transverse histological sample of approximately 1 cm thickness of the anterior part of each organism was cut and samples were dehydrated in ethanol and placed in xylene. Afterwards, samples were embedded in paraffin (58°C) in a vacuum stove (D'Aniello et al, 2016;Polese et al, 2016;Zupo et al, 2019). Histological sections of 7 lm thick were cut with a microtome and placed on slides covered with glycerin/albumin.…”

“…For histological staining, the samples were placed in xylene and rehydrated in ethanol to remove the paraffin. Then, half of the sections were stained with hematoxylin to assess tissue health (Polese et al, 2016;Zupo et al, 2019). The other half of sections were stained with toluidine blue (0.2% of toluidine blue in sodium acetate buffer) to assess the abundance of hemocytes (Gabe, 1968).…”

Histamine and histidine decarboxylase in the olfactory system and brain of the common cuttlefish Sepia officinalis (Linnaeus, 1758)

“…These are best studied in gastropods (Elste et al, 1990;Habib et al, 2015;Hegedűs et al, 2004;Matsuo et al, 2016;Ohsuga et al, 2000;Soinila et al, 1990;Wyeth & Croll, 2011), although these animals may also use other transmitters like nitric oxide (Elphick, Kemenes, Staras, & O'Shea, 1995;Wyeth & Croll, 2011), FMRFamide-related peptides (Nezlin & Voronezhskaya, 1997;Suzuki, Kimura, Sekiguchi, & Mizukami, 1997), and acetylcholine (Matsuo et al, 2014) in their OSNs. Cephalopods may also use multiple transmitters in their olfactory organs including nitric oxide (Di Cosmo et al, 2000;Di Cristo, De Lisa, & Di Cosmo, 2009;Emery, 1975) and FMRFamide-related peptides (Di Cosmo & Di Cristo, 1998;Polese, Bertapelle, & Di Cosmo, 2016;Wildenburg, 1997). Scaros et al, 2018 suggested that different subsets of OSNs might use different neurotransmitters.…”