Limits...
C. elegans sensing of and entrainment along obstacles require different neurons at different body locations.

Nam SW, Qian C, Kim SH, van Noort D, Chiam KH, Park S - Sci Rep (2013)

Bottom Line: We probe C. elegans mechanosensation using a microfabricated platform where worms encounter a linear array of asymmetric funnel-like barriers.We found that sensing of and moving along barriers require different sets of neurons located at different parts of the animal.Wild-type worms sense and move along the barrier walls, leading to their accumulation in one side of the barriers due to the barriers' asymmetric shape.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Nano Science, Ewha Global Top5 Research Program, Ewha Womans University, Seoul, Korea.

ABSTRACT
We probe C. elegans mechanosensation using a microfabricated platform where worms encounter a linear array of asymmetric funnel-like barriers. We found that sensing of and moving along barriers require different sets of neurons located at different parts of the animal. Wild-type worms sense and move along the barrier walls, leading to their accumulation in one side of the barriers due to the barriers' asymmetric shape. However, mec-4 and mec-10 mutants deficient in touch sensory neurons in the body exhibited reversal movements at the walls, leading to no accumulation in either side of the barriers. In contrast, osm-9 mutants deficient in touch sensory neurons in the nose, moved along the barrier walls. Thus, touch sensory neurons ALM and AVM in the body are required for C. elegans to sense and move along obstacles, whereas the ASH and FLP neurons in the nose are required only for sensing of but not moving along obstacles.

Show MeSH
Representative images and behaviors of wild-type (N2) and mutants after colliding with a funnel wall.(A) Representative images of N2. (B) Representative images of mec-4. (C) Distribution of incoming and outgoing angles (incoming: black lines with circles, outgoing: red lines with triangles), as well as schematic drawings of several instances of incoming and outgoing angles. (D) Retention times on the funnel wall. (E) Persistence lengths on the funnel wall. Asterisks denote values that are different from the value of the wild-type N2 at p < 0.0001 (One-way ANOVA with Bonferroni post-tests analysis). The values were plotted as the mean ± standard deviation of 50 independent worm's movements after touching the wall.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3842086&req=5

f3: Representative images and behaviors of wild-type (N2) and mutants after colliding with a funnel wall.(A) Representative images of N2. (B) Representative images of mec-4. (C) Distribution of incoming and outgoing angles (incoming: black lines with circles, outgoing: red lines with triangles), as well as schematic drawings of several instances of incoming and outgoing angles. (D) Retention times on the funnel wall. (E) Persistence lengths on the funnel wall. Asterisks denote values that are different from the value of the wild-type N2 at p < 0.0001 (One-way ANOVA with Bonferroni post-tests analysis). The values were plotted as the mean ± standard deviation of 50 independent worm's movements after touching the wall.

Mentions: Upon bumping into the funnel walls, most of wild-type worms first exhibited repeated forward and backward movements, but eventually moved along the walls, irrespective of their incoming angles toward the walls (Movie S1 and Fig. 3A). In contrast, mec-4 and mec-10 did not exhibit entrainment along the walls. Instead, they either retracted from the walls (Movie S2), or reversed their directions via omega turns (Fig. 3B). Omega turns were identified by the head nearly touching the tail or a reorientation of more than135° within a single head swing14.


C. elegans sensing of and entrainment along obstacles require different neurons at different body locations.

Nam SW, Qian C, Kim SH, van Noort D, Chiam KH, Park S - Sci Rep (2013)

Representative images and behaviors of wild-type (N2) and mutants after colliding with a funnel wall.(A) Representative images of N2. (B) Representative images of mec-4. (C) Distribution of incoming and outgoing angles (incoming: black lines with circles, outgoing: red lines with triangles), as well as schematic drawings of several instances of incoming and outgoing angles. (D) Retention times on the funnel wall. (E) Persistence lengths on the funnel wall. Asterisks denote values that are different from the value of the wild-type N2 at p < 0.0001 (One-way ANOVA with Bonferroni post-tests analysis). The values were plotted as the mean ± standard deviation of 50 independent worm's movements after touching the wall.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3842086&req=5

f3: Representative images and behaviors of wild-type (N2) and mutants after colliding with a funnel wall.(A) Representative images of N2. (B) Representative images of mec-4. (C) Distribution of incoming and outgoing angles (incoming: black lines with circles, outgoing: red lines with triangles), as well as schematic drawings of several instances of incoming and outgoing angles. (D) Retention times on the funnel wall. (E) Persistence lengths on the funnel wall. Asterisks denote values that are different from the value of the wild-type N2 at p < 0.0001 (One-way ANOVA with Bonferroni post-tests analysis). The values were plotted as the mean ± standard deviation of 50 independent worm's movements after touching the wall.
Mentions: Upon bumping into the funnel walls, most of wild-type worms first exhibited repeated forward and backward movements, but eventually moved along the walls, irrespective of their incoming angles toward the walls (Movie S1 and Fig. 3A). In contrast, mec-4 and mec-10 did not exhibit entrainment along the walls. Instead, they either retracted from the walls (Movie S2), or reversed their directions via omega turns (Fig. 3B). Omega turns were identified by the head nearly touching the tail or a reorientation of more than135° within a single head swing14.

Bottom Line: We probe C. elegans mechanosensation using a microfabricated platform where worms encounter a linear array of asymmetric funnel-like barriers.We found that sensing of and moving along barriers require different sets of neurons located at different parts of the animal.Wild-type worms sense and move along the barrier walls, leading to their accumulation in one side of the barriers due to the barriers' asymmetric shape.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Nano Science, Ewha Global Top5 Research Program, Ewha Womans University, Seoul, Korea.

ABSTRACT
We probe C. elegans mechanosensation using a microfabricated platform where worms encounter a linear array of asymmetric funnel-like barriers. We found that sensing of and moving along barriers require different sets of neurons located at different parts of the animal. Wild-type worms sense and move along the barrier walls, leading to their accumulation in one side of the barriers due to the barriers' asymmetric shape. However, mec-4 and mec-10 mutants deficient in touch sensory neurons in the body exhibited reversal movements at the walls, leading to no accumulation in either side of the barriers. In contrast, osm-9 mutants deficient in touch sensory neurons in the nose, moved along the barrier walls. Thus, touch sensory neurons ALM and AVM in the body are required for C. elegans to sense and move along obstacles, whereas the ASH and FLP neurons in the nose are required only for sensing of but not moving along obstacles.

Show MeSH