Mechanotransduction in epidermal Merkel cells

Area of Science:

• Neuroscience
• Cell Biology
• Sensory Physiology

Background:

• Vertebrate touch reception is poorly understood compared to other senses.
• Somatosensory afferents in the skin detect tactile qualities like pressure and flutter.
• The role of non-neuronal cells (e.g., Merkel cells) in touch transduction is debated.

Purpose of the Study:

• To investigate the cellular and molecular mechanisms of touch reception.
• To determine if Merkel cells actively participate in mechanosensory transduction.
• To elucidate the contribution of Merkel cells to slowly adapting type I (SAI) responses.

Main Methods:

• Whole-cell recordings in rodent models.
• Optogenetics and intact recordings.
• Loss-of-function studies in transgenic mouse models.

Main Results:

• Merkel cells are touch-sensitive and possess mechanically activated currents dependent on Piezo2.
• Merkel cells mediate sustained SAI firing patterns.
• SAI afferents are also touch sensitive, supporting a two-receptor site model.

Conclusions:

• Merkel cells play an active role in touch transduction.
• Piezo2 is crucial for Merkel cell mechanosensitivity and SAI responses.
• These findings revise the understanding of mechanosensory transduction in touch reception.