Hyperlipidemic Diet Causes Loss of Olfactory Sensory Neurons, Reduces Olfactory Discrimination, and Disrupts Odor-Reversal Learning

AbstractAlthough praying mantises rely mainly on vision for predatory behaviours, olfaction also plays a critical role in feeding and mating behaviours. However, the receptive processes underlying olfactory signals remain unclear. Here, we identified olfactory sensory neurons (OSNs) that are highly tuned to detect aldehydes in the mantis Tenodera aridifolia. In extracellular recordings from OSNs in basiconic sensilla on the antennae, we observed three different spike shapes, indicating that at least three OSNs are housed in a single basiconic sensillum. Unexpectedly, one of the three OSNs exhibited strong excitatory responses to a set of aldehydes. Based on the similarities of the response spectra to 15 different aldehydes, the aldehyde-specific OSNs were classified into three classes: B, S, and M. Class B broadly responded to most aldehydes used as stimulants; class S responded to short-chain aldehydes (C3–C7); and class M responded to middle-length chain aldehydes (C6–C9). Thus, aldehyde molecules can be finely discriminated based on the activity patterns of a population of OSNs. Because many insects emit aldehydes for pheromonal communication, mantises might use aldehydes as olfactory cues for locating prey habitat.

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Region-specific amyloid-β accumulation in the olfactory system influences olfactory sensory neuronal dysfunction in 5xFAD mice

Alzheimer s Research & Therapy ◽

10.1186/s13195-020-00730-2 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Gowoon Son ◽

Seung-Jun Yoo ◽

Shinwoo Kang ◽

Ameer Rasheed ◽

Da Hae Jung ◽

...

Keyword(s):

Olfactory Bulb ◽

Sensory Neurons ◽

Olfactory System ◽

Amyloid Β ◽

Olfactory Sensory Neurons ◽

Basal Cells ◽

Irreversible Damage ◽

5Xfad Mouse ◽

Peripheral Areas ◽

5Xfad Mice

Abstract Background Hyposmia in Alzheimer’s disease (AD) is a typical early symptom according to numerous previous clinical studies. Although amyloid-β (Aβ), which is one of the toxic factors upregulated early in AD, has been identified in many studies, even in the peripheral areas of the olfactory system, the pathology involving olfactory sensory neurons (OSNs) remains poorly understood. Methods Here, we focused on peripheral olfactory sensory neurons (OSNs) and delved deeper into the direct relationship between pathophysiological and behavioral results using odorants. We also confirmed histologically the pathological changes in 3-month-old 5xFAD mouse models, which recapitulates AD pathology. We introduced a numeric scale histologically to compare physiological phenomenon and local tissue lesions regardless of the anatomical plane. Results We observed the odorant group that the 5xFAD mice showed reduced responses to odorants. These also did not physiologically activate OSNs that propagate their axons to the ventral olfactory bulb. Interestingly, the amount of accumulated amyloid-β (Aβ) was high in the OSNs located in the olfactory epithelial ectoturbinate and the ventral olfactory bulb glomeruli. We also observed irreversible damage to the ectoturbinate of the olfactory epithelium by measuring the impaired neuronal turnover ratio from the basal cells to the matured OSNs. Conclusions Our results showed that partial and asymmetrical accumulation of Aβ coincided with physiologically and structurally damaged areas in the peripheral olfactory system, which evoked hyporeactivity to some odorants. Taken together, partial olfactory dysfunction closely associated with peripheral OSN’s loss could be a leading cause of AD-related hyposmia, a characteristic of early AD.

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G protein-coupled odorant receptors underlie mechanosensitivity in mammalian olfactory sensory neurons

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1418515112 ◽

2014 ◽

Vol 112 (2) ◽

pp. 590-595 ◽

Cited By ~ 43

Author(s):

Timothy Connelly ◽

Yiqun Yu ◽

Xavier Grosmaitre ◽

Jue Wang ◽

Lindsey C. Santarelli ◽

...

Keyword(s):

G Protein ◽

Sensory Neurons ◽

Ectopic Expression ◽

Host Cells ◽

Odorant Receptors ◽

Olfactory Sensory Neurons ◽

Mechanical Stimuli ◽

Genetic Ablation ◽

Mechanical Responses ◽

G Protein Coupled

Mechanosensitive cells are essential for organisms to sense the external and internal environments, and a variety of molecules have been implicated as mechanical sensors. Here we report that odorant receptors (ORs), a large family of G protein-coupled receptors, underlie the responses to both chemical and mechanical stimuli in mouse olfactory sensory neurons (OSNs). Genetic ablation of key signaling proteins in odor transduction or disruption of OR–G protein coupling eliminates mechanical responses. Curiously, OSNs expressing different OR types display significantly different responses to mechanical stimuli. Genetic swap of putatively mechanosensitive ORs abolishes or reduces mechanical responses of OSNs. Furthermore, ectopic expression of an OR restores mechanosensitivity in loss-of-function OSNs. Lastly, heterologous expression of an OR confers mechanosensitivity to its host cells. These results indicate that certain ORs are both necessary and sufficient to cause mechanical responses, revealing a previously unidentified mechanism for mechanotransduction.

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Developmental change in reversal learning of an olfactory discrimination

Psychobiology ◽

10.1007/bf03337783 ◽

1989 ◽

Vol 17 (3) ◽

pp. 293-299 ◽

Cited By ~ 6

Author(s):

Lawrence A. Saperstein ◽

David Kucharski ◽

Mark E. Stanton ◽

W. G. Hall

Keyword(s):

Reversal Learning ◽

Developmental Change ◽

Olfactory Discrimination

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