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Re-Classification of Drosophila melanogaster Trichoid and Intermediate Sensilla Using Fluorescence-Guided Single Sensillum Recording.

Lin CC, Potter CJ - PLoS ONE (2015)

Bottom Line: Drosophila olfactory receptor neurons are found within specialized sensory hairs on antenna and maxillary palps.Fluorescence-guided SSR further revealed that two antennal trichoid sensilla types should be re-classified as intermediate sensilla.This approach provides a simple and practical addition to a proven method for investigating olfactory neurons, and can be extended by the addition of UAS-geneX effectors for gain-of-function or loss-of-function studies.

View Article: PubMed Central - PubMed

Affiliation: The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.

ABSTRACT
Drosophila olfactory receptor neurons are found within specialized sensory hairs on antenna and maxillary palps. The linking of odorant-induced responses to olfactory neuron activities is often accomplished via Single Sensillum Recordings (SSR), in which an electrode inserted into a single sensory hair records the neuronal activities of all the neurons housed in that sensillum. The identification of the recorded sensillum requires matching the neuronal responses with known odor-response profiles. To record from specific sensilla, or to systematically screen all sensillar types, requires repetitive and semi-random SSR experiments. Here, we validate an approach in which the GAL4/UAS binary expression system is used for targeting specific sensilla for recordings. We take advantage of available OrX-Gal4 lines, in combination with recently generated strong membrane targeted GFP reporters, to guide electrophysiological recordings to GFP-labeled sensilla. We validate a full set of reagents that can be used to rapidly screen the odor-response profiles of all basiconic, intermediate, and trichoid sensilla. Fluorescence-guided SSR further revealed that two antennal trichoid sensilla types should be re-classified as intermediate sensilla. This approach provides a simple and practical addition to a proven method for investigating olfactory neurons, and can be extended by the addition of UAS-geneX effectors for gain-of-function or loss-of-function studies.

No MeSH data available.


Related in: MedlinePlus

Re-classification of Drosophila melanogaster intermediate and trichoid sensilla.(A) Schematic for the location of trichoid and intermediate sensilla on the antennae. (B) FgSSR analyses re-classified two trichoid sensilla (names bolded) as intermediate sensilla. Intermediate sensilla identification numbers are correlated to the number of housed neurons: ai1 contains one neuron, ai2 contains two neurons, and ai3 contains three neurons.
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pone.0139675.g005: Re-classification of Drosophila melanogaster intermediate and trichoid sensilla.(A) Schematic for the location of trichoid and intermediate sensilla on the antennae. (B) FgSSR analyses re-classified two trichoid sensilla (names bolded) as intermediate sensilla. Intermediate sensilla identification numbers are correlated to the number of housed neurons: ai1 contains one neuron, ai2 contains two neurons, and ai3 contains three neurons.

Mentions: During our validation of FgSSR, we found that some ORNs previously classified as “trichoid” [3] were not housed in what appeared to be trichoid sensilla. Instead, they were positioned in significantly shorter sensilla with thinner cuticles that are similar to intermediate sensilla [1]. With DIC combined with confocal images as the measurement of sensillar lengths (Fig 4A–4E), we found that these other sensilla were significantly shorter than trichoid sensilla, ranging from 10.38 ± 0.17μm for at2 and 8.49 ± 0.17 μm for at3 (as compared to traditional trichoid sensilla: 19.56 ± 0.31 μm for at1 and 17.7 ± 0.22 μm for at4) (Fig 4F and 4G). As the significant length differences between at1/at4 and at2/at3 likely underlied different categories of sensilla, we reclassified at2 and at3 into ai2 and ai3 respectively (Fig 5). To avoid confusion between past and future SSR studies, we did not rename at4. The 4 types of sensilla were distributed in the distolateral region on the antenna, with at1 in the proximal region, at4 at the distal region and intermixed ai2 and ai3 in between at1 and at4 (Fig 5A).


Re-Classification of Drosophila melanogaster Trichoid and Intermediate Sensilla Using Fluorescence-Guided Single Sensillum Recording.

Lin CC, Potter CJ - PLoS ONE (2015)

Re-classification of Drosophila melanogaster intermediate and trichoid sensilla.(A) Schematic for the location of trichoid and intermediate sensilla on the antennae. (B) FgSSR analyses re-classified two trichoid sensilla (names bolded) as intermediate sensilla. Intermediate sensilla identification numbers are correlated to the number of housed neurons: ai1 contains one neuron, ai2 contains two neurons, and ai3 contains three neurons.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4592000&req=5

pone.0139675.g005: Re-classification of Drosophila melanogaster intermediate and trichoid sensilla.(A) Schematic for the location of trichoid and intermediate sensilla on the antennae. (B) FgSSR analyses re-classified two trichoid sensilla (names bolded) as intermediate sensilla. Intermediate sensilla identification numbers are correlated to the number of housed neurons: ai1 contains one neuron, ai2 contains two neurons, and ai3 contains three neurons.
Mentions: During our validation of FgSSR, we found that some ORNs previously classified as “trichoid” [3] were not housed in what appeared to be trichoid sensilla. Instead, they were positioned in significantly shorter sensilla with thinner cuticles that are similar to intermediate sensilla [1]. With DIC combined with confocal images as the measurement of sensillar lengths (Fig 4A–4E), we found that these other sensilla were significantly shorter than trichoid sensilla, ranging from 10.38 ± 0.17μm for at2 and 8.49 ± 0.17 μm for at3 (as compared to traditional trichoid sensilla: 19.56 ± 0.31 μm for at1 and 17.7 ± 0.22 μm for at4) (Fig 4F and 4G). As the significant length differences between at1/at4 and at2/at3 likely underlied different categories of sensilla, we reclassified at2 and at3 into ai2 and ai3 respectively (Fig 5). To avoid confusion between past and future SSR studies, we did not rename at4. The 4 types of sensilla were distributed in the distolateral region on the antenna, with at1 in the proximal region, at4 at the distal region and intermixed ai2 and ai3 in between at1 and at4 (Fig 5A).

Bottom Line: Drosophila olfactory receptor neurons are found within specialized sensory hairs on antenna and maxillary palps.Fluorescence-guided SSR further revealed that two antennal trichoid sensilla types should be re-classified as intermediate sensilla.This approach provides a simple and practical addition to a proven method for investigating olfactory neurons, and can be extended by the addition of UAS-geneX effectors for gain-of-function or loss-of-function studies.

View Article: PubMed Central - PubMed

Affiliation: The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.

ABSTRACT
Drosophila olfactory receptor neurons are found within specialized sensory hairs on antenna and maxillary palps. The linking of odorant-induced responses to olfactory neuron activities is often accomplished via Single Sensillum Recordings (SSR), in which an electrode inserted into a single sensory hair records the neuronal activities of all the neurons housed in that sensillum. The identification of the recorded sensillum requires matching the neuronal responses with known odor-response profiles. To record from specific sensilla, or to systematically screen all sensillar types, requires repetitive and semi-random SSR experiments. Here, we validate an approach in which the GAL4/UAS binary expression system is used for targeting specific sensilla for recordings. We take advantage of available OrX-Gal4 lines, in combination with recently generated strong membrane targeted GFP reporters, to guide electrophysiological recordings to GFP-labeled sensilla. We validate a full set of reagents that can be used to rapidly screen the odor-response profiles of all basiconic, intermediate, and trichoid sensilla. Fluorescence-guided SSR further revealed that two antennal trichoid sensilla types should be re-classified as intermediate sensilla. This approach provides a simple and practical addition to a proven method for investigating olfactory neurons, and can be extended by the addition of UAS-geneX effectors for gain-of-function or loss-of-function studies.

No MeSH data available.


Related in: MedlinePlus