Liang Xin's research group in the School of Life Sciences revealed the cell biological mechanism of local stinging by Drosophila pain neurons

The animal's perception of mechanical force is a physiological process that transforms stimuli from external forces into biological signals
.
The perception of mechanical stimuli is the basis of a variety of sensory processes, including touch, hearing, and mechanical pain
.
In response to complex mechanical stimuli in the environment, organisms develop a wide variety of mechanore-sensing cells
.
Among them, mechanical pain sensing cells can feel nourishing external stimuli, allowing the organism to avoid danger, which is essential
for survival.
Previous studies have revealed that C4da neurons are neural pathways in which c4da neurons are involved in the neural pathway of pain sensation and the key force-sensitive ion channels responsible for sensing mechanical forces, but the cellular biology mechanisms by which such pain-sensing cells process mechanical force signals are still unclear
.

Fig.
1 Model schematic of the "mechanical force-optics" hybrid device

Fig.
2 Tissue in situ mechanical force and calcium imaging

On October 6, 2022, the Tsinghua University School of Life Sciences, Tsinghua-IDG/McGovern Institute of Brain Sciences Liang Xin research group published a research paper
entitled "Drosophila Mechanical Nociceptors Preferentially Sense Localized Poking" online in eLife magazine 。 In this paper, the self-built "mechanical-optics" combination device (Figure 1) was used to stimulate the c4da pain neurons in situ by performing in situ mechanical stimulation, and the responses of neurons to different types of force signals were simultaneously recorded and analyzed (Figure 2).

The discovery that c4da neurons are sensitive to milli-bovine-level mechanical stimuli while exhibiting higher sensitivity to stimuli with a smaller pressure distribution provides a cellular biological basis
for understanding the involvement of c4da neurons in sensing attacks by natural enemies of Drosophila larvae.
Further experimental and mechanical model analysis found that c4da neurons optimized their perception of mechanical pain stimuli by optimizing their own dendritic network morphology, developing sensitivity to lateral tissue tension and intradendritic active signal diffusion and other cellular biological mechanisms (Figure 3).

The results of this study, which combine research methods and techniques in many related fields such as biophysics and neuroscience, provide an important reference for further understanding the formation mechanism of mechanical pain and expand the basic knowledge
of cellular and molecular pathways for mechanical pain sensation.

Fig.
3 Cell biological mechanism of c4da nerve cells sensing local mechanical analgesia

Associate Professor Liang Xin of the School of Life Sciences of Tsinghua University is the corresponding author of this paper, Liu Zhen, a 2015 doctoral student of Tsinghua University, and Dr.
Wu Menghua, a postdoctoral student, are the co-first authors of this paper, and Dr.
Wang Qixuan of the Liang Xinshi Research Group of the School of Life Sciences of Tsinghua University provided important help
in the conduct of the experiment.
Professor Feng Xiqiao, Associate Professor Li Bo and Dr.
Lin Shaozhen of the Institute of Biomechanics and Medical Engineering, School of Aeronautics and Astronautics, Tsinghua University, completed the mechanical model analysis
in this work.
This research was supported
by the National Natural Science Foundation of China, the Tsinghua-Peking University Joint Center for Life Sciences, and the Tsinghua-IDG/McGovern Institute for Brain Sciences.

Original link: https://elifesciences.
org/articles/76574