Faculty Opinions recommendation of Nociceptive neurons protect Drosophila larvae from parasitoid wasps.

SummaryHere, we describe a targeted reverse genetic screen for thermal nociception genes of Drosophila larvae. Using laser capture microdissection and microarray analyses of nociceptive and non-nociceptive neurons we identified 275 nociceptor-enriched genes. We then tested the function of the enriched genes with nociceptor-specific RNAi and thermal nociception assays. Tissue specific RNAi targeted against 14 genes caused insensitive thermal nociception while targeting of 22 genes caused hypersensitive thermal nociception. Previously uncategorized genes were named for heat resistance (ie. boilerman, fire dancer, oven mitt, trivet, thawb and bunker gear) or heat sensitivity (firelighter, black match, eucalyptus, primacord, jet fuel, detonator, gasoline, smoke alarm, and jetboil). Insensitive nociception phenotypes were often associated with severely reduced branching of nociceptor neurites and hyperbranched dendrites were seen in two of the hypersensitive cases. Many genes that we identified were not isolated in a prior genome-wide screen, and are evolutionarily conserved in mammals.

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Formin3 directs dendritic architecture via microtubule regulation and is required for somatosensory nociceptive behavior

Development ◽

10.1242/dev.187609 ◽

2021 ◽

Author(s):

Ravi Das ◽

Shatabdi Bhattacharjee ◽

Jamin M. Letcher ◽

Jenna M. Harris ◽

Sumit Nanda ◽

...

Keyword(s):

Sensory Neurons ◽

Time Course ◽

Neuronal Function ◽

Nociceptive Behavior ◽

Noxious Heat ◽

Cytoskeletal Organization ◽

Nociceptive Neurons ◽

Charcot Marie Tooth ◽

Drosophila Larvae ◽

Severe Impairment

Dendrite shape impacts functional connectivity and is mediated by organization and dynamics of cytoskeletal fibers. Identifying molecular factors that regulate dendritic cytoskeletal architecture is therefore important in understanding mechanistic links between cytoskeletal organization and neuronal function. We identified Formin3 (Form3) as a critical regulator of cytoskeletal architecture in nociceptive sensory neurons in Drosophila larvae. Time course analyses reveal Form3 is cell-autonomously required to promote dendritic arbor complexity. We show that form3 is required for the maintenance of a population of stable dendritic microtubules (MTs), and mutants exhibit defects in the localization of dendritic mitochondria, satellite Golgi, and the TRPA channel Painless. Form3 directly interacts with MTs via FH1-FH2 domains. Mutations in human Inverted Formin 2 (INF2; ortholog of form3) have been causally linked to Charcot-Marie-Tooth (CMT) disease. CMT sensory neuropathies lead to impaired peripheral sensitivity. Defects in form3 function in nociceptive neurons result in severe impairment of noxious heat-evoked behaviors. Expression of the INF2 FH1-FH2 domains partially recovers form3 defects in MTs and nocifensive behavior, suggesting conserved functions, thereby providing putative mechanistic insights into potential etiologies of CMT sensory neuropathies.

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Larval Defense against Attack from Parasitoid Wasps Requires Nociceptive Neurons

PLoS ONE ◽

10.1371/journal.pone.0078704 ◽

2013 ◽

Vol 8 (10) ◽

pp. e78704 ◽

Cited By ~ 43

Author(s):

Jessica L. Robertson ◽

Asako Tsubouchi ◽

W. Daniel Tracey

Keyword(s):

Parasitoid Wasps ◽

Nociceptive Neurons

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Small conductance Ca2+-activated K+ channels induce the firing pause periods during the activation of Drosophila nociceptive neurons

eLife ◽

10.7554/elife.29754 ◽

2017 ◽

Vol 6 ◽

Cited By ~ 4

Author(s):

Koun Onodera ◽

Shumpei Baba ◽

Akira Murakami ◽

Tadashi Uemura ◽

Tadao Usui

Keyword(s):

Regulatory Mechanism ◽

Stereotyped Behavior ◽

Sk Channels ◽

Nociceptive Neurons ◽

Drosophila Larvae ◽

Rate Coding ◽

Thermal Stimuli ◽

Complex Spikes ◽

Small Conductance ◽

Class Iv

In Drosophila larvae, Class IV sensory neurons respond to noxious thermal stimuli and provoke heat avoidance behavior. Previously, we showed that the activated neurons displayed characteristic fluctuations of firing rates, which consisted of repetitive high-frequency spike trains and subsequent pause periods, and we proposed that the firing rate fluctuations enhanced the heat avoidance (Terada et al., 2016). Here, we further substantiate this idea by showing that the pause periods and the frequency of fluctuations are regulated by small conductance Ca2+-activated K+ (SK) channels, and the SK knockdown larvae display faster heat avoidance than control larvae. The regulatory mechanism of the fluctuations in the Class IV neurons resembles that in mammalian Purkinje cells, which display complex spikes. Furthermore, our results suggest that such fluctuation coding in Class IV neurons is required to convert noxious thermal inputs into effective stereotyped behavior as well as general rate coding.

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