Neurogenin2 specifies the connectivity of thalamic neurons by controlling axon responsiveness to intermediate target cues.
Many lines of evidence indicate that important traits of neuronal phenotype, such as cell body position and neurotransmitter expression, are specified through complex interactions between extrinsic and intrinsic genetic determinants. However, the molecular mechanisms specifying neuronal connectivity are less well understood at the transcriptional level. Here we demonstrate that the bHLH transcription factor Neurogenin2 cell autonomously specifies the projection of thalamic neurons to frontal cortical areas. Unexpectedly, Ngn2 determines the projection of thalamic neurons to specific cortical domains by specifying the responsiveness of their axons to cues encountered in an intermediate target, the ventral telencephalon. Our results thus demonstrate that in parallel to their well-documented proneural function, bHLH transcription factors also contribute to the specification of neuronal connectivity in the mammalian brain.
Seibt
Julie
J
INSERM U371, 18 Avenue Doyen Lépine, 69675 Bron, France.
Schuurmans
Carol
C
Gradwhol
Gérard
G
Dehay
Colette
C
Vanderhaeghen
Pierre
P
Guillemot
François
F
Polleux
Franck
F
D000818:Animals; D001369:Axons / Q000378:metabolism / Q000502:physiology*; D051792:Basic Helix-Loop-Helix Proteins; D002642:Chick Embryo; D005260:Female; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D009434:Neural Pathways / Q000196:embryology / Q000378:metabolism / Q000502:physiology; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D013788:Thalamus / Q000196:embryology / Q000378:metabolism / Q000502:physiology*
D051792:Basic Helix-Loop-Helix Proteins; D009419:Nerve Tissue Proteins; C102938:Neurog2 protein, mouse