Regenerating the central nervous system: how easy for planarians!

Dev Genes Evol. 2007 Dec;217(11-12):733-48. doi: 10.1007/s00427-007-0188-6. Epub 2007 Nov 13.


The regenerative capabilities of freshwater planarians (Platyhelminthes) are very difficult to match. A fragment as tiny as 1/279th of the planarian body is able to regenerate a whole animal within very few days [Morgan. Arch Entwm 7:364-397 (1898)]. Although the planarian central nervous system (CNS) may appear quite morphologically simple, recent studies have shown it to be more complex at the molecular level, revealing a high degree of molecular compartmentalization in planarian cephalic ganglia. Planarian neural genes include homologues of well-known transcription factors and genes involved in human diseases, neurotransmission, axon guidance, signaling pathways, and RNA metabolism. The availability of hundreds of genes expressed in planarian neurons coupled with the ability to silence them through the use of RNA interference makes it possible to start unraveling the molecular mechanisms underlying CNS regeneration. In this review, I discuss current knowledge on the planarian nervous system and the genes involved in its regeneration, and I discuss some of the important questions that remain to be answered.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Central Nervous System / metabolism
  • Central Nervous System / physiology*
  • Gene Expression Regulation, Developmental
  • Models, Biological
  • Neurons / classification
  • Neurons / cytology
  • Planarians / physiology*
  • Regeneration*