Search results for "OLFACTORY"
showing 10 items of 319 documents
Parvalbumin-containing interneurons do not innervate granule cells in the olfactory bulb
2001
Combining pre-embedding parvalbumin immunostaining and post-embedding immunogold detection of GABA in the olfactory bulb, we investigated whether the parvalbumin-containing GABAergic interneurons of the external plexiform layer exclusively innervate principal cells, or whether they also establish inhibitory synapses upon GABAergic local neurons such as granule cells. Our results demonstrate that the parvalbumin-containing cells do not contact GABAergic interneurons in the neuropil of the external plexiform layer. On the contrary, their postsynaptic elements were always non-GABAergic principal cells. Although classically it has been accepted that the interneurons of the external plexiform la…
Decreasing prevalence of specific anosmia to non-steroid odorants from childhood to adolescence
2020
International audience; Specific anosmia is defined as the inability to detect a particular odorant, despite a normal olfactory function. Previous studies reported sex-related difference in detection threshold to steroid odorants, like androstenone or androstadienone during adolescence, and boys showed an increased detection threshold with age. However, such investigations have not been performed for non-steroid odorants. Hence, the current study investigated sex- and age-related effects on the prevalence of specific anosmia in children/adolescents aged 5-14 years (n = 800) to non-steroid odorants. The detection thresholds of three non-steroid odorants (bacdanol, methylsalicylate, and 3-hyd…
An olfactory receptor for food-derived odours promotes male courtship in Drosophila.
2011
International audience; Many animals attract mating partners through the release of volatile sex pheromones, which can convey information on the species, gender and receptivity of the sender to induce innate courtship and mating behaviours by the receiver. Male Drosophila melanogaster fruitflies display stereotyped reproductive behaviours towards females, and these behaviours are controlled by the neural circuitry expressing male-specific isoforms of the transcription factor Fruitless (FRU(M)). However, the volatile pheromone ligands, receptors and olfactory sensory neurons (OSNs) that promote male courtship have not been identified in this important model organism. Here we describe a novel…
Effects of manganese injected into rat nostrils: implications for in vivo functional study of olfaction using MEMRI.
2011
WOS: 000298212500007; International audience; Manganese-enhanced magnetic resonance imaging (MEMRI) is a powerful tool for visualizing neuronal pathways and mapping brain activity modulation. A potential drawback of MEMRI lies in the toxic effects of manganese (Mn), which also depend on its administration route. The aim of this study was to analyze the effects of Mn doses injected into the nostrils of rats on both olfactory perception and MRI contrast enhancement. For this purpose, doses in the range 0-8 μmol MnCl(2) were tested. Behavioral items were quantified with and without odor stimulation during the first 2 h following Mn injection. The MRI study was performed after 16 h of intermitt…
Fixation conditions affect the intensity but not the pattern of NADPH-diaphorase staining as a marker for neuronal nitric oxide synthase in rat olfac…
1994
NADPH-diaphorase (NADPH-d) is commonly used as a histochemical marker for the neuronal form of the enzyme nitric oxide synthase (NOS). A recent biochemical study showed that in broken-cell preparations NADPH-d activity did not fully represent NOS and that NOS-unrelated NADPH-d activity was suppressed during fixation. Because it is unknown whether fixation also affects NOS-associated NADPH-d activity, we investigated the effects of various widely used fixatives on NADPH-d staining in relation to NOS immunoreactivity, obtained with polyclonal antibodies, in rat olfactory bulb. We found that the intensity of NADPH-d staining associated with NOS, as well as that unrelated to NOS, depends on fi…
A binary genetic approach to characterize TRPM5 cells in mice
2015
International audience; Transient receptor potential channel subfamily M member 5 (TRPM5) is an important downstream signaling component in a subset of taste receptor cells making it a potential target for taste modulation. Interestingly, TRPM5 has been detected in extra-oral tissues; however, the function of extra-gustatory TRPM5-expressing cells is less well understood. To facilitate visualization and manipulation of TRPM5-expressing cells in mice, we generated a Cre knock-in TRPM5 allele by homologous recombination. We then used the novel TRPM5-IRES-Cre mouse strain to report TRPM5 expression by activating a tau GFP transgene. To confirm faithful coexpression of tau GFP and TRPM5 we gene…
Characterization of rat glutathione transferases in olfactory epithelium and mucus
2019
International audience; The olfactory epithelium is continuously exposed to exogenous chemicals, including odorants. During the past decade, the enzymes surrounding the olfactory receptors have been shown to make an important contribution to the process of olfaction. Mammalian xenobiotic metabolizing enzymes, such as cytochrome P450, esterases and glutathione transferases (GSTs), have been shown to participate in odorant clearance from the olfactory receptor environment, consequently contributing to the maintenance of sensitivity toward odorants. GSTs have previously been shown to be involved in numerous physiological processes, including detoxification, steroid hormone biosynthesis, and am…
Chronic restraint stress and chronic corticosterone treatment modulate differentially the expression of molecules related to structural plasticity in…
2004
Stress and stress-related hormones induce structural changes in neurons of the adult CNS. Neurons in the hippocampus, the amygdala and the prefrontal cortex undergo neurite remodeling after chronic stress. In the hippocampus some of these effects can be mimicked with chronic administration of adrenal steroids. These changes in neuronal structure may be mediated by certain molecules related to plastic events such as the polysialylated form of the neural cell adhesion molecule (PSA-NCAM). The expression of PSA-NCAM persists in the adult hippocampus and it is up-regulated after chronic stress. The piriform cortex also displays considerable levels of PSA-NCAM during adulthood and indirect evide…
Cellular composition and three-dimensional organization of the subventricular germinal zone in the adult mammalian brain.
1997
The adult mammalian subventricular zone (SVZ) contains stem cells that give rise to neurons and glia.In vivo, SVZ progeny migrate 3–8 mm to the olfactory bulb, where they form neurons. We show here that the SVZ of the lateral wall of the lateral ventricles in adult mice is composed of neuroblasts, glial cells, and a novel putative precursor cell. The topographical organization of these cells suggests how neurogenesis and migration are integrated in this region. Type A cells had the ultrastructure of migrating neuronal precursors. These cells were arranged as chains parallel to the walls of the ventricle and were polysialylated neural adhesion cell molecule- (PSA–NCAM), TuJ1- (β-tubulin), an…
Subventricular Zone Astrocytes Are Neural Stem Cells in the Adult Mammalian Brain
1999
AbstractNeural stem cells reside in the subventricular zone (SVZ) of the adult mammalian brain. This germinal region, which continually generates new neurons destined for the olfactory bulb, is composed of four cell types: migrating neuroblasts, immature precursors, astrocytes, and ependymal cells. Here we show that SVZ astrocytes, and not ependymal cells, remain labeled with proliferation markers after long survivals in adult mice. After elimination of immature precursors and neuroblasts by an antimitotic treatment, SVZ astrocytes divide to generate immature precursors and neuroblasts. Furthermore, in untreated mice, SVZ astrocytes specifically infected with a retrovirus give rise to new n…