WNT-7a induces axonal remodeling and increases synapsin I levels in cerebellar neurons

Dev Biol. 1997 Dec 1;192(1):31-44. doi: 10.1006/dbio.1997.8734.


WNT factors play a key role in early patterning of the embryo. However, expression of Wnt genes after cell commitment suggests additional roles in later developmental processes. We report here that Wnt-7a is expressed in cerebellar granule cell neurons as they begin to extend processes and form synapses. WNT-7a increases axonal spreading and branching in cultured granule cells. Moreover, WNT-7a increases the levels of synapsin I, a presynaptic protein involved in synapse formation and function. Lithium mimics WNT-7a in granule cells by inhibiting GSK-3beta, a component of the WNT signaling pathway. These results suggest a direct effect of WNT-7a in the regulation of neuronal cytoskeleton and synapsin I in granule cell neurons. We propose that WNT proteins have a novel function in the formation of neuronal connections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / ultrastructure*
  • Bipolar Disorder / drug therapy
  • Bipolar Disorder / metabolism
  • Cell Differentiation
  • Cells, Cultured
  • Cerebellum / cytology
  • Cerebellum / embryology*
  • Cerebellum / metabolism*
  • Gene Expression Regulation, Developmental
  • Humans
  • In Situ Hybridization
  • Lithium / pharmacology
  • Mice
  • Neurons / drug effects
  • Neurons / metabolism
  • Neurons / ultrastructure
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism*
  • RNA / genetics
  • RNA / metabolism
  • Synapsins / metabolism*
  • Wnt Proteins


  • Proto-Oncogene Proteins
  • Synapsins
  • WNT7A protein, human
  • Wnt Proteins
  • Wnt7a protein, mouse
  • RNA
  • Lithium