Morphological, neurochemical and electrophysiological features of parvalbumin-expressing cells: a likely source of axo-axonic inputs in the mouse spinal dorsal horn

J Physiol. 2012 Aug 15;590(16):3927-51. doi: 10.1113/jphysiol.2012.235655. Epub 2012 Jun 6.

Abstract

Perception of normal bodily sensations relies on the precise regulation of sensory information entering the dorsal horn of the spinal cord. Inhibitory, axoaxonic, synapses provide a mechanism for this regulation, but the source of these important inhibitory connections remains to be elucidated. This study shows that a subpopulation of spinal interneurons that expresses parvalbumin and have specific morphological, connectivity and functional characteristics are a likely source of the inhibitory inputs that selectivity regulate non-noxious tactile input in the spinal cord. Our findings suggest that a loss of normal function in parvalbumin positive dorsal horn neurons may result in the development of tactile allodynia, where non-painful stimuli gain the capacity to evoke the sensation of pain.

MeSH terms

  • Action Potentials
  • Animals
  • Antibodies
  • Axons / physiology*
  • Electrophysiological Phenomena / physiology*
  • Gene Expression Regulation / physiology*
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred ICR
  • Mice, Transgenic
  • Muscle Fibers, Fast-Twitch / metabolism
  • Parvalbumins / genetics
  • Parvalbumins / metabolism*
  • Patch-Clamp Techniques
  • Posterior Horn Cells / physiology*
  • Posterior Horn Cells / ultrastructure
  • Ultraviolet Rays

Substances

  • Antibodies
  • Parvalbumins
  • Green Fluorescent Proteins