scholarly journals Response plasticity of Drosophila olfactory sensory neurons

2021 ◽  
Author(s):  
Lorena Halty-deLeon ◽  
Venkatesh Pal Mahadevan ◽  
Bill S. Hansson ◽  
Dieter Wicher
Keyword(s):  
Sensory Neurons ◽  
Time Window ◽  
Active Role ◽  
Receptor Activation ◽  
Olfactory Sensory Neurons ◽  
Response Dynamics ◽  
Olfactory Signal ◽  
Intracellular Ca ◽  
Food Odors ◽  
Vinegar Fly

AbstractIn insect olfaction, sensitization refers to the amplification of a weak olfactory signal when the stimulus is repeated within a specific time window. In the vinegar fly, Drosophila melanogaster, his occurs already at the periphery, at the level of olfactory sensory neurons (OSNs) located in the antenna. In our study, we investigate whether sensitization is a widespread property in a set of seven types of OSNs, as well as the mechanisms involved. First, we characterize and compare differences in spontaneous activity, response velocity and response dynamics among the selected OSN types. These express different receptors with distinct tuning properties and behavioral relevance. Second, we show that sensitization is not a general property. Among our selected OSNs types, it occurs in those responding to more general food odors, while OSNs involved in very specific detection of highly specific ecological cues like pheromones and warning signals show no sensitization. Moreover, we show that mitochondria play an active role in sensitization by contributing to the increase in intracellular Ca2+ upon weak receptor activation. Thus, by using a combination of single sensillum recordings (SSR), calcium imaging and pharmacology, we widen the understanding of how the olfactory signal is processed at the periphery.Abstract Figure

scholarly journals Functional Interaction Between Drosophila Olfactory Sensory Neurons and Their Support Cells

2022 ◽  
Vol 15 ◽  
Author(s):  
Sinisa Prelic ◽  
Venkatesh Pal Mahadevan ◽  
Vignesh Venkateswaran ◽  
Sofia Lavista-Llanos ◽  
Bill S. Hansson ◽  
...  
Keyword(s):  
Sensory Neurons ◽  
Ex Vivo ◽  
Active Role ◽  
Cell Types ◽  
Olfactory Sensory Neurons ◽  
Functional Interaction ◽  
Supporting Cells ◽  
Volatile Chemicals ◽  
Odor Detection ◽  
Support Cell

Insects detect volatile chemicals using antennae, which house a vast variety of olfactory sensory neurons (OSNs) that innervate hair-like structures called sensilla where odor detection takes place. In addition to OSNs, the antenna also hosts various support cell types. These include the triad of trichogen, tormogen, and thecogen support cells that lie adjacent to their respective OSNs. The arrangement of OSN supporting cells occurs stereotypically for all sensilla and is widely conserved in evolution. While insect chemosensory neurons have received considerable attention, little is known about the functional significance of the cells that support them. For instance, it remains unknown whether support cells play an active role in odor detection, or only passively contribute to homeostasis, e.g., by maintaining sensillum lymph composition. To investigate the functional interaction between OSNs and support cells, we used optical and electrophysiological approaches in Drosophila. First, we characterized the distribution of various supporting cells using genetic markers. By means of an ex vivo antennal preparation and genetically-encoded Ca2+ and K+ indicators, we then studied the activation of these auxiliary cells during odor presentation in adult flies. We observed acute responses and distinct differences in Ca2+ and K+ fluxes between support cell types. Finally, we observed alterations in OSN responses upon thecogen cell ablation in mature adults. Upon inducible ablation of thecogen cells, we notice a gain in mechanical responsiveness to mechanical stimulations during single-sensillum recording, but a lack of change to the neuronal resting activity. Taken together, these results demonstrate that support cells play a more active and responsive role during odor processing than previously thought. Our observations thus reveal that support cells functionally interact with OSNs and may be important for the extraordinary ability of insect olfactory systems to dynamically and sensitively discriminate between odors in the turbulent sensory landscape of insect flight.

scholarly journals Functional interaction between Drosophila olfactory sensory neurons and their support cells

2021 ◽  
Author(s):  
Sinisa Prelic ◽  
Venkatesh Pal Mahadevan ◽  
Vignesh Venkateswaran ◽  
Sofia Lavista-Llanos ◽  
Bill S. Hansson ◽  
...  
Keyword(s):  
Sensory Neurons ◽  
Ex Vivo ◽  
Active Role ◽  
Cell Types ◽  
Olfactory Sensory Neurons ◽  
Functional Interaction ◽  
Supporting Cells ◽  
Volatile Chemicals ◽  
Odor Detection ◽  
Support Cell

AbstractInsects detect volatile chemicals using antennae, which house a vast variety of olfactory sensory neurons (OSNs) that innervate hair-like structures called sensilla where odor detection takes place. In addition to OSNs, the antenna also hosts various support cell types. These include the triad of trichogen, tormogen and thecogen support cells that lie adjacent to their respective OSNs. The arrangement of OSN supporting cells occurs stereotypically for all sensilla and is widely conserved in evolution. While insect chemosensory neurons have received considerable attention, little is known about the functional significance of the cells that support them. For instance, it remains unknown whether support cells play an active role in odor detection, or only passively contribute to homeostasis, e.g. by maintaining sensillum lymph composition. To investigate the functional interaction between OSNs and support cells, we used optical and electrophysiological approaches in Drosophila. First, we characterized the distribution of various supporting cells using genetic markers. By means of an ex vivo antennal preparation and genetically-encoded Ca2+ and K+ indicators, we then studied the activation of these auxiliary cells during odor presentation in adult flies. We observed acute responses and distinct differences in Ca2+ and K+ fluxes between support cell types. Finally, we observed alterations in OSN responses upon thecogen cell ablation in mature adults. Upon inducible ablation of thecogen cells, we notice a gain in mechanical responsiveness to mechanical stimulations during single-sensillum recording, but a lack of change to neuronal resting activity. Taken together, these results demonstrate that support cells play a more active and responsive role during odor processing than previously thought. Our observations thus reveal that support cells functionally interact with OSNs and may be important for the extraordinary ability of insect olfactory systems to dynamically and sensitively discriminate between odors in the turbulent sensory landscape of insect flight.

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