Olfactory sensory axons expressing a dominant-negative semaphorin receptor enter the CNS early and overshoot their target

Neuron. 2000 Nov;28(2):437-47. doi: 10.1016/s0896-6273(00)00123-9.


Sensory axons extend from the chick olfactory epithelium to the telencephalon well before the maturation of their target, the olfactory bulb. During a waiting period of several days, olfactory axons arrive and accumulate outside the CNS while the bulb differentiates beneath them. Semephorin-3A is expressed in the tel-encephalon during this period and has been proposed to prevent their entry into the CNS. We show that the misexpression of a dominant-negative neuropilin-1 that blocks SEMA-3A-mediated signaling in olfactory sensory axons induces many of them to enter the tel-encephalon prematurely and to overshoot the olfactory bulb. These results suggest that chemorepellents can prevent the premature innervation of immature targets.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Axons / metabolism*
  • Axons / ultrastructure
  • Central Nervous System / cytology
  • Central Nervous System / embryology
  • Chick Embryo
  • Electroporation
  • Genes, Dominant
  • Intercellular Signaling Peptides and Proteins
  • Nerve Tissue Proteins / biosynthesis*
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neurons, Afferent / cytology
  • Neurons, Afferent / metabolism*
  • Neuropilin-1
  • Olfactory Nerve / embryology*
  • Olfactory Nerve / metabolism
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / genetics
  • Semaphorin-3A
  • Telencephalon / embryology
  • Transfection


  • Intercellular Signaling Peptides and Proteins
  • Nerve Tissue Proteins
  • Recombinant Proteins
  • Semaphorin-3A
  • collapsin response mediator protein-2
  • Neuropilin-1