Piezo2 is required for Merkel-cell mechanotransduction

Area of Science:

• Neuroscience
• Mechanobiology
• Somatic Sensation

Background:

• The Merkel cell-neurite complex is crucial for gentle touch sensation, but its mechanotransduction mechanism remains unknown.
• The roles of Merkel cells and afferent nerve fibers in sensing mechanical force are debated.
• Understanding the molecular basis of touch sensation is a fundamental challenge in neuroscience.

Purpose of the Study:

• To elucidate the molecular mechanism of mechanotransduction in Merkel cells.
• To determine the role of Piezo2 channels in gentle touch sensation.
• To investigate the functional contribution of Merkel cells to the Merkel cell-neurite complex.

Main Methods:

• In vitro electrophysiology to record touch-sensitive currents in Merkel cells.
• Generation of genetically engineered mice with Piezo2 deficiency specifically in skin Merkel cells.
• In vivo electrophysiological recordings of sensory nerve responses and behavioral assays for touch sensitivity.

Main Results:

• Merkel cells exhibit touch-sensitive currents dependent on Piezo2 expression.
• Mice lacking Piezo2 in Merkel cells show reduced slowly adapting responses and impaired gentle touch behavior.
• Evidence supports a two-receptor-site model involving both Merkel cells and afferent fibers.

Conclusions:

• Piezo2 is identified as the primary mechanotransduction channel in Merkel cells for gentle touch.
• This study provides the first evidence for a physiological role of Piezo channels in mammalian mechanosensation.
• A dual-receptor model highlights the cooperative sensing function of Merkel cells and afferent neurons.