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Olfactory epithelium changes in germfree mice.

François A, Grebert D, Rhimi M, Mariadassou M, Naudon L, Rabot S, Meunier N - Sci Rep (2016)

Bottom Line: These changes were associated with a decreased transcription of most olfactory transduction actors and of olfactory xenobiotic metabolising enzymes.Overall, we present here the first evidence that the microbiota modulates the physiology of olfactory epithelium.As olfaction is a major sensory modality for most animal species, the microbiota may have an important impact on animal physiology and behaviour through olfaction alteration.

View Article: PubMed Central - PubMed

Affiliation: NBO, UVSQ, INRA, Université Paris-Saclay, F-78350 Jouy-en-Josas, France.

ABSTRACT
Intestinal epithelium development is dramatically impaired in germfree rodents, but the consequences of the absence of microbiota have been overlooked in other epithelia. In the present study, we present the first description of the bacterial communities associated with the olfactory epithelium and explored differences in olfactory epithelium characteristics between germfree and conventional, specific pathogen-free, mice. While the anatomy of the olfactory epithelium was not significantly different, we observed a thinner olfactory cilia layer along with a decreased cellular turn-over in germfree mice. Using electro-olfactogram, we recorded the responses of olfactory sensitive neuronal populations to various odorant stimulations. We observed a global increase in the amplitude of responses to odorants in germfree mice as well as altered responses kinetics. These changes were associated with a decreased transcription of most olfactory transduction actors and of olfactory xenobiotic metabolising enzymes. Overall, we present here the first evidence that the microbiota modulates the physiology of olfactory epithelium. As olfaction is a major sensory modality for most animal species, the microbiota may have an important impact on animal physiology and behaviour through olfaction alteration.

No MeSH data available.


Related in: MedlinePlus

Global increase of responses to odorants recorded by EOG in germfree animals.(A,B) EOG responses to various odorants in conventional and germfree animals. Values represent the mean of peak amplitudes ± SEM (n = 12) (*P < 0.05; **P < 0.01; ***P < 0.001). (C) Average traces for 3 odorants from conventional (black) and germfree (red) animals. Small black line on top of recordings indicates odorant stimulation.
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f3: Global increase of responses to odorants recorded by EOG in germfree animals.(A,B) EOG responses to various odorants in conventional and germfree animals. Values represent the mean of peak amplitudes ± SEM (n = 12) (*P < 0.05; **P < 0.01; ***P < 0.001). (C) Average traces for 3 odorants from conventional (black) and germfree (red) animals. Small black line on top of recordings indicates odorant stimulation.

Mentions: To assess whether the presence of microbiota could affect the OSN responses to odorants, we performed EOG recordings. We stimulated the OE with increasing concentrations of heptanal and limonene as well as several other odorants. Part of the variation of EOG signal may be based on the microbial metabolism of odorants. We therefore chose odorants with the greatest variety of organic groups and structures (Supplementary Table 1). We measured the maximum amplitude of responses to odorants (Fig. 3) and different kinetics parameters (Supplementary Table 1). The maximum amplitude of responses was significantly increased in germfree animals for all odorants, except acetophenone and pyridine, at all dilutions used (Fig. 3A,B). Despite the higher peak amplitude of the EOG responses, the area of the signal was often not statistically different between conventional and germfree animals, indicating that the response kinetic was affected as well (Supplementary Table 1). Indeed, the depolarization and repolarization phases of the EOG responses were systematically faster in germfree animals, except for the fast component of the repolarization phase in response to acetophonenone 10−3. The repolarization phase was less affected than the depolarization without any clear link with odorant structure (Fig. 3C and Supplementary Table 1).


Olfactory epithelium changes in germfree mice.

François A, Grebert D, Rhimi M, Mariadassou M, Naudon L, Rabot S, Meunier N - Sci Rep (2016)

Global increase of responses to odorants recorded by EOG in germfree animals.(A,B) EOG responses to various odorants in conventional and germfree animals. Values represent the mean of peak amplitudes ± SEM (n = 12) (*P < 0.05; **P < 0.01; ***P < 0.001). (C) Average traces for 3 odorants from conventional (black) and germfree (red) animals. Small black line on top of recordings indicates odorant stimulation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835764&req=5

f3: Global increase of responses to odorants recorded by EOG in germfree animals.(A,B) EOG responses to various odorants in conventional and germfree animals. Values represent the mean of peak amplitudes ± SEM (n = 12) (*P < 0.05; **P < 0.01; ***P < 0.001). (C) Average traces for 3 odorants from conventional (black) and germfree (red) animals. Small black line on top of recordings indicates odorant stimulation.
Mentions: To assess whether the presence of microbiota could affect the OSN responses to odorants, we performed EOG recordings. We stimulated the OE with increasing concentrations of heptanal and limonene as well as several other odorants. Part of the variation of EOG signal may be based on the microbial metabolism of odorants. We therefore chose odorants with the greatest variety of organic groups and structures (Supplementary Table 1). We measured the maximum amplitude of responses to odorants (Fig. 3) and different kinetics parameters (Supplementary Table 1). The maximum amplitude of responses was significantly increased in germfree animals for all odorants, except acetophenone and pyridine, at all dilutions used (Fig. 3A,B). Despite the higher peak amplitude of the EOG responses, the area of the signal was often not statistically different between conventional and germfree animals, indicating that the response kinetic was affected as well (Supplementary Table 1). Indeed, the depolarization and repolarization phases of the EOG responses were systematically faster in germfree animals, except for the fast component of the repolarization phase in response to acetophonenone 10−3. The repolarization phase was less affected than the depolarization without any clear link with odorant structure (Fig. 3C and Supplementary Table 1).

Bottom Line: These changes were associated with a decreased transcription of most olfactory transduction actors and of olfactory xenobiotic metabolising enzymes.Overall, we present here the first evidence that the microbiota modulates the physiology of olfactory epithelium.As olfaction is a major sensory modality for most animal species, the microbiota may have an important impact on animal physiology and behaviour through olfaction alteration.

View Article: PubMed Central - PubMed

Affiliation: NBO, UVSQ, INRA, Université Paris-Saclay, F-78350 Jouy-en-Josas, France.

ABSTRACT
Intestinal epithelium development is dramatically impaired in germfree rodents, but the consequences of the absence of microbiota have been overlooked in other epithelia. In the present study, we present the first description of the bacterial communities associated with the olfactory epithelium and explored differences in olfactory epithelium characteristics between germfree and conventional, specific pathogen-free, mice. While the anatomy of the olfactory epithelium was not significantly different, we observed a thinner olfactory cilia layer along with a decreased cellular turn-over in germfree mice. Using electro-olfactogram, we recorded the responses of olfactory sensitive neuronal populations to various odorant stimulations. We observed a global increase in the amplitude of responses to odorants in germfree mice as well as altered responses kinetics. These changes were associated with a decreased transcription of most olfactory transduction actors and of olfactory xenobiotic metabolising enzymes. Overall, we present here the first evidence that the microbiota modulates the physiology of olfactory epithelium. As olfaction is a major sensory modality for most animal species, the microbiota may have an important impact on animal physiology and behaviour through olfaction alteration.

No MeSH data available.


Related in: MedlinePlus