Stomatin and sensory neuron mechanotransduction

J Neurophysiol. 2007 Dec;98(6):3802-8. doi: 10.1152/jn.00860.2007. Epub 2007 Oct 17.

Abstract

Somatic sensory neurons of the dorsal root ganglia are necessary for a large part of our mechanosensory experience. However, we only have a good knowledge of the molecules required for mechanotransduction in simple invertebrates such as the nematode Caenorhabiditis elegans. In C. elegans, a number of so-called mec genes have been isolated that are required for the transduction of body touch. One such gene, mec-2 codes for an integral membrane protein of the stomatin family, a large group of genes with a stomatin homology domain. Using stomatin null mutant mice, we have tested the hypothesis that the founding member of this family, stomatin might play a role in the transduction of mechanical stimuli by primary sensory neurons. We used the in vitro mouse skin nerve preparation to record from a large population of low- and high-threshold mechanoreceptors with myelinated A-fiber (n = 553) and unmyelinated C-fiber (n = 157) axons. One subtype of mechanoreceptor, the d-hair receptor, which is a rapidly adapting mechanoreceptor, had reduced sensitivity to mechanical stimulation in the absence of stomatin. Other cutaneous mechanoreceptors, including nociceptive C-fibers were not affected by the absence of a functional stomatin protein. Patch-clamp analysis of presumptive D-hair receptor mechanoreceptive neurons, which were identified by a characteristic rosette morphology in culture, showed no change in membrane excitability in the absence of the stomatin protein. We conclude that stomatin is required for normal mechanotransduction in a subpopulation of vertebrate sensory neurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Proteins / genetics*
  • Blood Proteins / physiology*
  • Electrophysiology
  • Hair / physiology
  • Mechanoreceptors / physiology
  • Mechanotransduction, Cellular / physiology*
  • Membrane Proteins / genetics*
  • Membrane Proteins / physiology*
  • Mice
  • Mice, Knockout
  • Nerve Fibers, Myelinated / physiology
  • Nerve Fibers, Unmyelinated / physiology
  • Neurons, Afferent / physiology*
  • Nociceptors / physiology
  • Patch-Clamp Techniques
  • Skin / innervation*

Substances

  • Blood Proteins
  • Epb7.2 protein, mouse
  • Membrane Proteins