ASICs mediate fast excitatory synaptic transmission for tactile discrimination

Area of Science:

• Neuroscience
• Sensory Biology
• Mechanotransduction

Background:

• Tactile discrimination is crucial for interacting with the environment and development.
• Merkel cell-neurite complexes (MNCs) are key sensory organs for touch.
• The precise mechanism of tactile signal encoding in MNCs was previously unclear.

Purpose of the Study:

• To investigate how tactile signals are encoded at the cellular level within Merkel cell-neurite complexes (MNCs).
• To identify the molecular mechanisms underlying signal transmission in MNCs.
• To determine the role of identified channels in tactile perception.

Main Methods:

• Electrophysiological recordings from rodent whisker hair follicles.
• Pharmacological inhibition of acid-sensing ion channels (ASICs).
• Genetic deletion of ASICs in animal models.

Main Results:

• Tactile signals are transmitted via fast excitatory synaptic transmission in MNCs.
• Acid-sensing ion channels (ASICs) on neurites mediate this transmission, using protons as transmitters.
• Inhibiting or deleting ASICs disrupted tactile signal encoding and impaired tactile discrimination.

Conclusions:

• Acid-sensing ion channels (ASICs) are essential for encoding tactile information in MNCs.
• Proton-mediated signaling through ASICs is critical for mammalian tactile discrimination.
• This discovery provides a molecular basis for understanding touch perception.