Olfactory Sensory Neuron Morphotypes in the Featherback Fish, Notopterus notopterus (Osteoglossiformes: Notopteridae)

Abstract

BackgroundAs in other vertebrates, olfactory sensory neurons (OSNs) in fishes are the main components of sensory part of olfactory epithelium that relay olfactory information (smell and taste) to the brain.PurposeObjective of the present study was to analyze if any polymorphism occurs in the OSNs in a featherback fish, Notopterus notopterus as far as the teleost lineage is concerned.MethodsWith the help of neuronal staining technique, polymorphism of OSNs in N. notopterus was studied.ResultsThree polymorphic forms of OSNs were identified which are ciliated OSNs, microvillus OSNs and crypt OSNs. These morphotypes were identified on the basis of location of their somata within the depth of olfactory epithelium and resulting length of their dendrites. The ciliated OSNs have basally situated somata and long, thin dendrites with a few apically arranged cilia while microvillous OSNs have somata located midway in the epithelium and thick moderate-length dendrites with microvilli. Third cell type is crypt OSNs which are spherical or pear-shaped, located apically just close to the epithelial surface having cilia and microvilli in an invagination and devoid of any dendrite.ConclusionN. notopterus belongs to order Osteoglossiformes which is a representative of an early evolutionary lineage of teleost fishes. OSN polymorphism reported in the present work indicates that it is a fairly conserved trait throughout the evolution of teleosts. To our knowledge, we are the first ones to report OSN polymorphism in a member of the order Osteoglossiformes.

Tissue Microenvironments in the Nasal Epithelium of Rainbow Trout (Oncorhynchus mykiss) Define Two Distinct CD8α+ Cell Populations and Establish Regional Immunity

“…In particular, the chemosensory portion of the nasal cavity, the olfactory epithelium, contains no goblet cells (24). In teleosts, the olfactory organ is also divided into sensory and non-sensory regions, however, the location of these regions varies in different species (25, 26). The sensory region of the olfactory lamella contains olfactory sensory neurons including ciliated, microvillus, and crypt cells (26–28), whilst the non-sensory region is a mucosal epithelium characterized by the presence of goblet cells.…”

The preorbital depression and recess of antiarch placoderms (jawed stem-gnathostomes) revisited from an ontogenetic (saltatory) point of view

“…This depression may have been used for particle filtration (Dupret et al, 2010) or as a protection device (Janvier, 1996; Zhu and Janvier, 1996) for the nasal openings of these benthic animals that were probably burrowing in the sediment (Cloutier et al, 2011; Béchard et al, 2014; Chevrinais et al, 2017b; Trinajstic and Roelofs, 2019). Extant fishes with bottom-dwelling habits, such as inferred for antiarchs, often show special adaptations to avoid clogging of their olfactory system, such as tube-shaped nostrils (Kasumyan, 2004; Patle and Baile, 2014) or accessory olfactory sacs (sometimes producing mucus) helping to remove mud particles from the olfactory organ (Døving et al, 1977). Also, numerous features in front of the nostrils of extant fishes serve to direct the water flow into the olfactory chamber such as skin flaps, funnels, grooves, or depressions (Cox, 2008; Tierney, 2015).…”

“…As for the visual acuity, variation in olfactory acuity depends on many features of the olfactory organs: the number of primary and secondary lamellae, the number of olfactory buds, the density and the surface area of the olfactory epithelium, and the density and type of olfactory sensory neurons composing the olfactory epithelium (Kasumyan, 2004;Schluessel et al, 2008Schluessel et al, , 2010Theiss et al, 2009;Meredith and Kajiura, 2010;Howard et al, 2013;Patle and Baile, 2014;Blin et al, 2018;Ferrando et al, 2019). The size of the region of the brain analysing the olfactory cues (olfactory bulbs; Lisney et al, 2007Lisney et al, , 2017Yopak et al, 2015) also plays a role in the olfactory acuity.…”

Histomorphological and microanatomical characteristics of the olfactory organ of freshwater carp, Cirrhinus reba (Hamilton)

“…The olfactory organs of fish are widely diversified depending on systematic groups and ecological habitats (Zeiske et al 2009). The structure and function of the fish olfactory organs have been investigated by a number of researchers using light and electron microscopes (Bhute and Baile 2007, Ghosh and Chakrabarti 2009, Ma and Wang 2010, Atta 2013, Patle and Baile 2014, Ghosh et al 2015, Samajdar and Mandal 2016. Studies show there is immense diversity regarding shape, the number and position of olfactory lamellae, the distribution of sensory and non-sensory epithelium, and the abundance of various receptor cell types in several teleosts depending on their adaptation to different behavoirs and habitats.…”

“…Studies show there is immense diversity regarding shape, the number and position of olfactory lamellae, the distribution of sensory and non-sensory epithelium, and the abundance of various receptor cell types in several teleosts depending on their adaptation to different behavoirs and habitats. Reports are also available on the morphohistological peculiarities of the olfactory organs of cyprinidae (Ojha and Kapoor 1973, Bhute and Baile 2007, Ghosh and Chakrabarti 2013, 2014, 2015, Samajdar and Mandal 2016. The oval and multi-lamellar olfactory rosette of cyprinids are characterized by linguiform processes that belong to the group of "eye-nose fishes."…”