PIEZO1 Is Selectively Expressed in Small Diameter Mouse DRG Neurons Distinct From Neurons Strongly Expressing TRPV1

Area of Science:

• Neuroscience
• Molecular Biology
• Pain Research

Background:

• The molecular mechanisms underlying mechanosensation and nociception are incompletely understood.
• Dorsal root ganglion (DRG) neurons transmit sensory information, including touch, proprioception, and pain, to the central nervous system.
• Ion channels like PIEZO and TRPV1 are known to play critical roles in sensory transduction.

Purpose of the Study:

• To investigate the expression patterns of PIEZO1, PIEZO2, and TRPV1 transcripts in mouse DRG neurons.
• To explore the potential role of PIEZO1 in mediating mechanical pain (mechano-nociception).

Main Methods:

• High-resolution in situ hybridization to quantify transcript levels of PIEZO1, PIEZO2, and TRPV1 in mouse DRG neurons.
• In vivo functional assays using PIEZO1-specific agonist (Yoda1) and TRPV1-specific agonist (capsaicin) to assess mechanical hyperalgesia.

Main Results:

• PIEZO2 transcripts were ubiquitously expressed in DRG neurons of all sizes.
• PIEZO1 transcripts were selectively found in small DRG neurons, distinct from most TRPV1-expressing neurons.
• Yoda1 induced prolonged mechanical hyperalgesia, suggesting PIEZO1's role in pain signaling.

Conclusions:

• PIEZO1 is selectively expressed in small DRG neurons, a population implicated in nociception.
• PIEZO1 represents a promising candidate for the long-sought channel mediating mechano-nociception.
• These findings advance our understanding of the molecular basis of pain perception.