Keratinocytes can modulate and directly initiate nociceptive responses
- University of Connecticut, United States
- University of Alabama, United States
- University of Pittsburgh, United States
Abstract
How thermal, mechanical and chemical stimuli applied to the skin are transduced into signals transmitted by peripheral neurons to the CNS is an area of intense study. Several studies indicate that transduction mechanisms are intrinsic to cutaneous neurons and that epidermal keratinocytes only modulate this transduction. Using mice expressing channelrhodopsin (ChR2) in keratinocytes we show that blue light activation of the epidermis alone can produce action potentials (APs) in multiple types of cutaneous sensory neurons including SA1, A-HTMR, CM, CH, CMC, CMH and CMHC fiber types. In loss of function studies, yellow light stimulation of keratinocytes that express halorhodopsin reduced AP generation in response to naturalistic stimuli. These findings support the idea that intrinsic sensory transduction mechanisms in epidermal keratinocytes can direct AP firing in nociceptor as well as tactile sensory afferents and suggest a significantly expanded role for the epidermis in sensory processing.
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Ethics
Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. Animals were handled in compliance with an approved Institutional Animal Care and Use Committee (IACUC) protocol (#14074296) of the University of Pittsburgh. All surgery was performed under appropriate anesthesia with every effort was made to minimize pain.
Copyright
© 2015, Baumbauer et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Keratinocytes can modulate and directly initiate nociceptive responses
eLife 4:e09674.
https://doi.org/10.7554/eLife.09674
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