Merkel cells transduce and encode tactile stimuli to drive Aβ-afferent impulses.

Bibliographic Collection: 
MOCA Reference, APE
Publication Type: Journal Article
Authors: Ikeda, Ryo; Cha, Myeounghoon; Ling, Jennifer; Jia, Zhanfeng; Coyle, Dennis; Gu, Jianguo G
Year of Publication: 2014
Journal: Cell
Volume: 157
Issue: 3
Pagination: 664-75
Date Published: 2014 Apr 24
Publication Language: eng
ISSN: 1097-4172
Keywords: Action Potentials, Animals, Calcium, Gene Knockdown Techniques, Ion Channels, Mechanoreceptors, Mechanotransduction, Cellular, Merkel Cells, Rats, Touch, Vibrissae

Sensory systems for detecting tactile stimuli have evolved from touch-sensing nerves in invertebrates to complicated tactile end organs in mammals. Merkel discs are tactile end organs consisting of Merkel cells and Aβ-afferent nerve endings and are localized in fingertips, whisker hair follicles, and other touch-sensitive spots. Merkel discs transduce touch into slowly adapting impulses to enable tactile discrimination, but their transduction and encoding mechanisms remain unknown. Using rat whisker hair follicles, we show that Merkel cells rather than Aβ-afferent nerve endings are primary sites of tactile transduction and identify the Piezo2 ion channel as the Merkel cell mechanical transducer. Piezo2 transduces tactile stimuli into Ca(2+)-action potentials in Merkel cells, which drive Aβ-afferent nerve endings to fire slowly adapting impulses. We further demonstrate that Piezo2 and Ca(2+)-action potentials in Merkel cells are required for behavioral tactile responses. Our findings provide insights into how tactile end-organs function and have clinical implications for tactile dysfunctions.

DOI: 10.1016/j.cell.2014.02.026
Alternate Journal: Cell
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