Development Genes and Evolution

, Volume 217, Issue 11–12, pp 733–748 | Cite as

Regenerating the central nervous system: how easy for planarians!

  • Francesc CebriàEmail author


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.


Planarian Central nervous system Neural genes Regeneration Axon guidance Neurotransmission 



I would like to thank Kiyokazu Agata, Chiyoko Kobayashi, Yoshihiko Umesono, Phillip A. Newmark, Tingxia Guo, Ricardo M. Zayas, and the laboratory of Emili Saló for helpful discussions on the planarian CNS; Hidefumi Orii and Emili Saló for their helpful comments; and Miquel Vila Farré for providing the specimens of Polycelis felina and Phagocata ullala used for the immunostaining shown in Fig. 1. I also thank Dr. Iain Patten for the advice on the English style in a version of the manuscript. The antibody 3C11 (anti-synapsin) used in Fig. 1 and developed by Dr. E. Buchner was obtained from the Developmental Studies Hybridoma Bank developed under the auspices of the NICHD and maintained by the University of Iowa, Department of Biological Sciences, Iowa City, USA. F.C. is supported by the Beatriu de Pinós (Generalitat de Catalunya) and Ramón y Cajal (Ministery of Education and Culture, Spain) programs.


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© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Departament de Genètica, Facultat de Biologia and Institut de Biomedicina de la Universitat de Barcelona (IBUB)BarcelonaSpain

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