Related Experiment Videos
High-resolution structure of hair-cell tip links
1Section on Structural Cell Biology, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892-4163, USA. kachab@nidcd.nih.gov
Summary
The gating spring in hair cells is likely not the tip link filament. High-resolution imaging reveals the tip link
Area of Science:
- Auditory neuroscience
- Cellular biophysics
- Mechanotransduction
Background:
- Hair cells are sensory receptors in the inner ear responsible for hearing and balance.
- Mechanical stimuli are converted into electrical signals by mechanotransduction channels.
- A gating spring is hypothesized to regulate these channels, but its identity remains unclear.
Purpose of the Study:
- To investigate the structural properties of the tip link, a candidate for the gating spring.
- To determine if the tip link's structure is consistent with the known elasticity of the gating spring.
Main Methods:
- Rapid-freeze, deep-etch electron microscopy was employed for high-resolution imaging.
- Structural analysis of the tip link filament connecting stereocilia.
Main Results:
- The tip link was visualized as a right-handed, coiled double filament.
- The tip link structure suggests it is stiff and inextensible.
- This observed stiffness is incompatible with the measured elasticity of the gating spring.
Conclusions:
- The tip link, as visualized, is unlikely to be the gating spring itself.
- The gating spring is proposed to be located in series with the helical segment of the tip link.