Specificity of monosynaptic sensory-motor connections imposed by repellent Sema3E-PlexinD1 signaling

Cell Rep. 2013 Nov 14;5(3):748-58. doi: 10.1016/j.celrep.2013.10.005. Epub 2013 Nov 7.

Abstract

In mammalian spinal cord, group Ia proprioceptive afferents form selective monosynaptic connections with a select group of motor pool targets. The extent to which sensory recognition of motor neurons contributes to the selectivity of sensory-motor connections remains unclear. We show here that proprioceptive sensory afferents that express PlexinD1 avoid forming monosynaptic connections with neurons in Sema3E(+) motor pools yet are able to form direct connections with neurons in Sema3E(off) motor pools. Anatomical and electrophysiological analysis of mice in which Sema3E-PlexinD1 signaling has been deregulated or inactivated genetically reveals that repellent signaling underlies aspects of the specificity of monosynaptic sensory-motor connectivity in these reflex arcs. A semaphorin-based system of motor neuron recognition and repulsion therefore contributes to the formation of specific sensory-motor connections in mammalian spinal cord.

Publication types

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

MeSH terms

  • Animals
  • Cytoskeletal Proteins
  • Glycoproteins / biosynthesis
  • Glycoproteins / genetics
  • Glycoproteins / metabolism*
  • Intracellular Signaling Peptides and Proteins
  • Membrane Glycoproteins / biosynthesis
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism*
  • Membrane Proteins / biosynthesis
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Motor Neurons / cytology
  • Motor Neurons / metabolism*
  • Nerve Tissue Proteins / biosynthesis
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neural Pathways / cytology
  • Neural Pathways / metabolism*
  • Semaphorins
  • Sensory Receptor Cells / cytology
  • Sensory Receptor Cells / metabolism*
  • Signal Transduction
  • Substrate Specificity

Substances

  • Cytoskeletal Proteins
  • Glycoproteins
  • Intracellular Signaling Peptides and Proteins
  • Membrane Glycoproteins
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Plxnd1 protein, mouse
  • Sema3e protein, mouse
  • Semaphorins