Drosophila mechanical nociceptors preferentially sense localized poking

  1. Zhen Liu
  2. Meng-Hua Wu
  3. Qi-Xuan Wang
  4. Shao-Zhen Lin
  5. Xi-Qiao Feng
  6. Bo Li
  7. Xin Liang  Is a corresponding author
  1. School of Life Sciences, Tsinghua University, China
  2. Institute of Biomechanics and Medical Engineering, Department of Engineering Mechanics, Tsinghua University, China
10 figures, 1 video and 1 additional file

Figures

Figure 1 with 1 supplement
The 'mechanical-optical' recording system.

(A) The cartoon schematics for the ‘mechanical-optical’ recording system (left) and the contact model between a spherical probe and the larval fillet (right). Vin was the driving voltage of the …

Figure 1—figure supplement 1
The customized ‘mechanical-optical’ recording system.

(A) The mechanical device was mounted on the working stage of a spinning-disk confocal microscope. (B) The mechanical device. Yellow box: the piezo actuator. Cyan box: the beam coupled with a strain …

Figure 2 with 3 supplements
The mechanosensory features of c4da.

(A) A representative image of c4da. The forces were applied at about 100 μm from the soma, i.e. along the green dashed circle. The representative force application points were marked using the …

Figure 2—figure supplement 1
Mechanosensory responses of c1da and c3da.

(A) Left panel: the representative image showing that c1da made no responses to a 4 mN compressive force. Right panel: Statistical quantification of the responses of c1da to compressive forces (4 …

Figure 2—figure supplement 2
The responses of c4da-wt to distal stimuli have a linear scaling relationship with the pressure (Px μm).

The responses of c4da to distal stimuli versus the pressures measured at 5 μm, 10 μm and 15 μm away from the center of the force (P5 μm, P10 μm, P15 μm). Data were presented as mean ± sem (n=10 …

Figure 2—figure supplement 3
The forces delivered using different stimulation probes.

For each probe size, five fibers were used to measure the poking forces. The poking forces had no dependence on the probe size. Mann Whitney U test was used. ns: no significance.

Figure 3 with 1 supplement
The contribution of dendritic morphology to the sensory features of c4da.

(A) The schematic showing the force application points (filled circles, green: 30 μm probe, red: 60 μm probe, orange: 100 μm probe) on c4da-cti. The dashed concentric circles were 100 and 200 μm in …

Figure 3—figure supplement 1
The expression and localization of the mechanosensory molecules and cytoskeletal elements in c4da-cti.

(A) The representative images of the mechanosensory molecules in c4da-wt and c4da-cti. c4da-wt (GFP-Piezo): gfp-piezo/ppk-gal4; ppk-cd4-tdtom/+. c4da-cti (GFP-Piezo): gfp-piezo/ppk-gal4; …

Figure 4 with 1 supplement
The mechanosensitivity of c4da to lateral tension.

(A) The responses of c4da (ΔF/F0) to the d-off stimuli (4 mN, 60 μm probe) applied at different positions.The numbers of cells were indicated below the scattered data points. Mann Whitney U test was …

Figure 4—figure supplement 1
Mechanical modeling analysis on the distribution of PP and TL.

(A) Cartoon schematics for the mechanical model used in the finite element analysis. PP, pressure perpendicular to the cuticle surface. TL, tension parallel with the cuticle surface. (B) …

The differential contributions of Piezo and Ppk1/Ppk26 to the mechanosensitivity of c4da.

(A) Representative images of c4da-piezoKO (piezoKO; ppk-cd4-tdtom/+), c4da-ppk261 (uas-cd4-tdtom/ppk-gal4; ppk261), c4da-piezoKO, ppkΔ5 (piezoKO, ppkΔ5; ppk-cd4-tdtom/+). Scale bar: 100 μm. (B) …

Figure 6 with 2 supplements
Active signal propagation in the dendrites of c4da.

(A) Representative images and curves showing the responses (ΔF/F0) of the soma (red arrowhead), the homolateral dendrite (position p1: yellow arrowhead) and contralateral dendrite (position p2: …

Figure 6—figure supplement 1
Statistics quantification of the calcium increase in the contralateral dendrites in response to the force stimuli.

C4da-wt: ppk-gal4/+; ppk-cd4-tdtom/20×uas-ivs-gcamp6s. Scrambledi: ppk-gal4/20×uas-ivs-gcamp6s, ppk-cd4-tdtom/uas-Scrambledi. Ca-α1Di: ppk-gal4/20×uas-ivs-gcamp6s; ppk-cd4-tdtom/uas-Ca-α1Di. Ca-α1DX1…

Figure 6—figure supplement 2
The expression and localization of Ca-α1D in vivo.

(A) The expression level of Ca-α1D in wild-type and Ca-α1Di was examined using RT-PCR. Because Ca-α1D expressed in various types of neurons and the number of c4da in the whole animal was small, we …

The cellular mechanisms that facilitate the mechanosensory features of c4da.

Left panel: c4da showed a greater sensitivity to localized poking forces and made uniform responses to the forces applied at different dendritic regions (p) proximal stimuli. (d) distal stimuli. …

Author response image 1
The schematics for how the probe was mounted.

As shown in the picture, the force probe was firmly mounted in the double-layered holder. These glass probes were short and solid, so they would not be bent during the experiments.

Author response image 2
Representative TEM micrographs on Drosophila larval fillet preparation.

The thickness of the cuticle was indicated. The samples were prepared using high pressure freezing and freeze substitution as previously described9.

Author response image 3
The mechanosensitivity to lateral tension increases the probability of cell activation.

(A) The representative color map for the distance to the nearest dendrite, in which the distance was labeled by different colors. Scale bar, 100 μm. Random positions were chosen (the red crosses) as …

Videos

Video 1
The representative response of a c4da cell to the 4 mN force stimulus.

The asterisk indicated the force application point and the white arrowhead indicated the soma.

Additional files

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