The cellular and molecular basis of direction selectivity of Aδ-LTMRs

Michael Rutlin; Cheng-Ying Ho; Victoria E Abraira; Colleen Cassidy; Ling Bai; C Jeffery Woodbury; David D Ginty

doi:10.1016/j.cell.2014.11.038

The cellular and molecular basis of direction selectivity of Aδ-LTMRs

Cell. 2014 Dec 18;159(7):1640-51. doi: 10.1016/j.cell.2014.11.038.

Authors

Michael Rutlin¹, Cheng-Ying Ho², Victoria E Abraira³, Colleen Cassidy⁴, Ling Bai, C Jeffery Woodbury⁵, David D Ginty⁶

Affiliations

¹ Solomon H. Snyder Department of Neuroscience, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA.
² Solomon H. Snyder Department of Neuroscience, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA; Department of Pathology, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA.
³ Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Solomon H. Snyder Department of Neuroscience, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA.
⁴ Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA.
⁵ Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA. Electronic address: woodbury@uwyo.edu.
⁶ Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Solomon H. Snyder Department of Neuroscience, Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA. Electronic address: david_ginty@hms.harvard.edu.

Abstract

The perception of touch, including the direction of stimulus movement across the skin, begins with activation of low-threshold mechanosensory neurons (LTMRs) that innervate the skin. Here, we show that murine Aδ-LTMRs are preferentially tuned to deflection of body hairs in the caudal-to-rostral direction. This tuning property is explained by the finding that Aδ-LTMR lanceolate endings around hair follicles are polarized; they are concentrated on the caudal (downward) side of each hair follicle. The neurotrophic factor BDNF is synthesized in epithelial cells on the caudal, but not rostral, side of hair follicles, in close proximity to Aδ-LTMR lanceolate endings, which express TrkB. Moreover, ablation of BDNF in hair follicle epithelial cells disrupts polarization of Aδ-LTMR lanceolate endings and results in randomization of Aδ-LTMR responses to hair deflection. Thus, BDNF-TrkB signaling directs polarization of Aδ-LTMR lanceolate endings, which underlies direction-selective responsiveness of Aδ-LTMRs to hair deflection.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Animals
Brain-Derived Neurotrophic Factor / metabolism
Embryo, Mammalian
Epithelial Cells / physiology
Ganglia, Spinal / physiology*
Hair Follicle / cytology
Hair Follicle / physiology*
In Vitro Techniques
Mechanoreceptors / classification
Mechanoreceptors / physiology*
Mice
Receptor, trkB / metabolism
Touch*

Substances

Brain-Derived Neurotrophic Factor
Receptor, trkB

Abstract

Publication types

MeSH terms

Substances

Grants and funding