scholarly journals Predicting the response of olfactory sensory neurons to odor mixtures from single odor response

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Addolorata Marasco ◽  
Alessandro De Paris ◽  
Michele Migliore
2019 ◽  
Author(s):  
Shigenori Inagaki ◽  
Ryo Iwata ◽  
Masakazu Iwamoto ◽  
Takeshi Imai

SUMMARYSensory information is selectively or non-selectively inhibited and enhanced in the brain, but it remains unclear whether this occurs commonly at the peripheral stage. Here, we performed two-photon calcium imaging of mouse olfactory sensory neurons (OSNs) in vivo and found that odors produce not only excitatory but also inhibitory responses at their axon terminals. The inhibitory responses remained in mutant mice, in which all possible sources of presynaptic lateral inhibition were eliminated. Direct imaging of the olfactory epithelium revealed widespread inhibitory responses at OSN somata. The inhibition was in part due to inverse agonism toward the odorant receptor. We also found that responses to odor mixtures are often suppressed or enhanced in OSNs: Antagonism was dominant at higher odor concentrations, whereas synergy was more prominent at lower odor concentrations. Thus, odor responses are extensively tuned by inhibition, antagonism, and synergy, at the early peripheral stage, contributing to robust odor representations.


2019 ◽  
Author(s):  
Joseph D. Zak ◽  
Gautam Reddy ◽  
Massimo Vergassola ◽  
Venkatesh N. Murthy

AbstractOdor landscapes contain complex blends of discrete molecules that each activate unique, overlapping populations of olfactory sensory neurons (OSNs). Despite the presence of hundreds of OSN subtypes in many animals, the overlapping nature of odor inputs may lead to saturation of neural responses at the early stages of stimulus encoding. Information loss due to saturation could be mitigated by normalizing mechanisms such as antagonism at the level of receptor-ligand interactions, whose existence and prevalence remains uncertain. By imaging OSN axon terminals in olfactory bulb glomeruli as well as OSN cell bodies within the olfactory epithelium in freely breathing mice, we found widespread antagonistic interactions in binary odor mixtures. In complex mixtures of up to 12 odorants, antagonistic interactions became stronger and more prevalent with increasing mixture complexity. Therefore, antagonism is a remarkably common feature of odor mixture encoding in olfactory sensory neurons and helps in normalizing activity to reduce saturation.


2019 ◽  
Author(s):  
Lu Xu ◽  
Wenze Li ◽  
Venkatakaushik Voleti ◽  
Elizabeth M. C. Hillman ◽  
Stuart Firestein

AbstractWe utilized swept confocally aligned planar excitation (SCAPE) microscopy to measure odor-driven activity simultaneously in many (>10,000) olfactory sensory neurons distributed over large areas of intact mouse olfactory epithelium. This approach allowed us to investigate the responses to mixtures or blends of odors and their components, a more realistic stimulus than monomolecular odors. In up to 38% of responding cells, responses to a mixture of odors were different - absent, smaller or larger - than what would be expected from the sum of the individual components. Further investigation revealed instances of both antagonism and allosteric enhancement in the primary olfactory sensory neurons. All 10 of the odor compounds tested were found to act as both agonists and antagonists at different receptors. We present a hypothetical scheme for how modulation at the peripheral receptors increases the capability of the olfactory system to recognize patterns of complex odor mixtures. The widespread modulation of primary sensory receptors argues against a simple combinatorial code and should motivate a search for alternative coding strategies.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kota Ezaki ◽  
Takashi Yamashita ◽  
Thomas Carle ◽  
Hidehiro Watanabe ◽  
Fumio Yokohari ◽  
...  

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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