Automated Analysis of a Nematode Population-based Chemosensory Preference Assay
Abstract
The nematode, Caenorhabditis elegans' compact nervous system of only 302 neurons underlies a diverse repertoire of behaviors. To facilitate the dissection of the neural circuits underlying these behaviors, the development of robust and reproducible behavioral assays is necessary. Previous C. elegans behavioral studies have used variations of a "drop test", a "chemotaxis assay", and a "retention assay" to investigate the response of C. elegans to soluble compounds. The method described in this article seeks to combine the complementary strengths of the three aforementioned assays. Briefly, a small circle in the middle of each assay plate is divided into four quadrants with the control and experimental solutions alternately placed. After the addition of the worms, the assay plates are loaded into a behavior chamber where microscope cameras record the worms' encounters with the treated regions. Automated video analysis is then performed and a preference index (PI) value for each video is generated. The video acquisition and automated analysis features of this method minimizes the experimenter's involvement and any associated errors. Furthermore, minute amounts of the experimental compound are used per assay and the behavior chamber's multi-camera setup increases experimental throughput. This method is particularly useful for conducting behavioral screens of genetic mutants and novel chemical compounds. However, this method is not appropriate for studying stimulus gradient navigation due to the close proximity of the control and experimental solution regions. It should also not be used when only a small population of worms is available. While suitable for assaying responses only to soluble compounds in its current form, this method can be easily modified to accommodate multimodal sensory interaction and optogenetic studies. This method can also be adapted to assay the chemosensory responses of other nematode species.
Additional Information
© 2017 Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Date Published: 7/13/2017. Some strains were provided by the Caenorhabditis Genetics Center (CGC), which is funded by NIH Office of Research Infrastructure Programs (P40 OD010440). This work is supported by the Howard Hughes Medical Institute, with which P.W.S. is an investigator.Attached Files
Published - jove-protocol-55963-automated-analysis-nematode-population-based-chemosensory-preference.pdf
Supplemental Material - JoVE_template.pptx
Supplemental Material - Supplementary_Video_1.mp4
Supplemental Material - Supplementary_video_2.mp4
Files
Additional details
- PMCID
- PMC5612354
- Eprint ID
- 79583
- Resolver ID
- CaltechAUTHORS:20170731-091632206
- NIH
- P40 OD010440
- Howard Hughes Medical Institute (HHMI)
- Created
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2017-08-01Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field