Browsing by Subject "Olfaction"

Now showing 1 - 4 of 4
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    Comparative analysis of the olfactory organs in selected species of marine sharks and freshwater batoids
    (Elsevier GmbH, 2021-07-29) Dymek, Jakub; Muñoz, Pilar; Mayo-Hernández, Elvira; Kuciel, Michał; Zuwała, Krystyna; Sanidad Animal
    We present comparative analysis of the micro- and macro-morphology of the olfactory organ of six neoselachians living in different habitats: two freshwater benthopelagic batoids, Potamotrygon motoro and Potamotrygon hystrix (Potamotrygonidae) as well as four species of sharks occupying the outer continental shelves and upper slopes Mustelus mustelus (Trikidae) and Scyliorhinus canicula (Scyliorhinidae), and deep-water Galeus melastomus (Scyliorhinidae) and Etmopterus spinax (Etmopteridae). Our research used light and electron (TEM, SEM) microscopes as well as macroscopic observations. The position of the nostrils in relation to the mouth varied in these species but all of them possessed elongate olfactory rosettes with primary lamellae arranged over two rows. The types of primary lamellae were distinguished based on their arrangement on the opposite sides of the median raphe as well as morphology of secondary lamellae and distribution of sensory and non-sensory regions of olfactory epithelium lining the lamellae; these were different between batoids and sharks. Analysis of olfactory epithelium revealed the presence of microvillous olfactory sensory neurons as the only type of receptor cells in all studied species whereas ionocytes were recognized only in sharks. All species possessed one type of goblet cells (Alcian Blue or Periodic Acid Schiff positives) except for P. motoro in which both types of goblet cells were present. Moreover, apical parts of non-sensory microvillous cells that lined the basal parts of the primary lamellae, possessed PAS-positive mucous granules; these were present in both species of batoids. This analogous region was abundant in goblet cells in the species of sharks studied here. Results indicated that differences between freshwater and marine species as well as between marine species occupying various habitat zones include mainly nostrils position, density of occurrence of ionocytes and goblet cells within olfactory epithelium as well as biochemical character of mucus
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    Effects of chronic low-level copper exposure on ultrastructure of the olfactory system in rain bow trout (Oncorhynchus mykiss)
    (Murcia : F. Hernández, 1993) Julliard, A.K.; Saucier, D.; Astic, L.
    This study investigated the effects of a chronic exposure to a low level of copper on cell populations of the olfactory system in yearling rainbow trout. Fish were sacrificed after 15, 30 and 60 days of copper exposure. Transmission electron microscopy was used to describe the sequence of subcellular changes occurring in three tissues, the sensory epithelium, the olfactory nerve and the olfactory bulb. Data show that a 15-day exposure to 20 pg/l of copper causes specific degeneration of al1 mature receptor cells as well as numerous immature neurons. Moreover, degenerating receptor cells exhibited morphological features of a cell death by apoptosis. After 30 days, and more specifically after 60 days of exposure, numerous clusters of cells were observed in the basa1 region of the epithelium, suggesting a great mitotic activity in this area. In parallel, an increased number of maturing receptor cells and goblet cells were observed, but no fully mature neurons were noted even after 60 days of exposure. In both the olfactory nerve and the olfactory bulb, the number of degenerating axons and terminals, which was high at 15 days, decreased with time and some process of glomerular reinnervation was detected after 60 days. A reactive hypertrophy of supporting, ensheathing and astrocytic cells was also observed in exposed fish, which demonstrates that these cell types are actively involved in the process of tissue scarring. Even though some signs of neurona1 regeneration were reported during the time-course of exposure, indicating some fish acclimation, results raise the question of the olfactory function during such environmental stress.
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    Modificaciones en la mucosa olfatoria de ratones adultos jóvenes expuestos al humo de cigarrillo
    (Universidad de Murcia. Servicio de publicaciones, 2022) Dávila Vera, Delsy; Mendoza Briceño, Rosa Virginia; Andrade Ruiz, Henry; Peña Contreras, Zulma; Torres Vielma, Yzoleth; Labarca Villasmil, Emilitza; Zavala Morillo, Leisalba; Gregorio Peña, José; Sánchez Gil, Beluardi; Vergara Dávila, Yulianny
    Se analizaron las alteraciones ocasionados por el humo de cigarrillo en la mucosa olfatoria, haciendo énfasis en el epitelio olfatorio, en ratones NMRI adultos jóvenes distribuidos en un grupo control y cuatro grupos experimentales expuestos al humo de cigarrillo a distintas dosis y tiempos. El efecto de los tóxicos presentes en el humo de cigarrillo, durante el tiempo de exposición experimentalmente programado, produjo leves modificaciones de la citoarquitectura epitelial como son la distribución irregular de las células y el desplazamiento de un alto porcentaje de ellas hacia la superficie; así como un incremento de la producción de sustancia mucosa verificada por microscopía óptica y de barrido, lo cual afecta la actividad normal del epitelio olfatorio.
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    The Grueneberg ganglion, a novel sensory system in the nose
    (Murcia : F. Hernández, 2010) Fleischer, Joerg; Breer, Heinz
    Within the nasal epithelium of mammals, there are several compartments which are populated with neuronal cells. One of them – the so-called Grueneberg ganglion – is composed of ciliated neurons residing in the anterior region of the nose. Although cells of the Grueneberg ganglion lack direct contact with the lumen of the nasal cavity, they are endowed with features indicative of olfactory sensory neurons, such as the olfactory marker protein and distinct olfactory receptors, as well as projection of axonal processes to the olfactory bulb of the brain. These findings have led to the notion that the Grueneberg ganglion might be a novel olfactory subsystem; a concept which was lately supported by the observation that chemical cues activate Grueneberg ganglion neurons. Unexpectedly, it was recently found that these cells also respond to cool ambient temperatures, presumably via a signaling pathway mediated by second messengers. Thus, the Grueneberg ganglion may operate as a dual sensory organ involved in the detection of both chemical and thermal stimuli.