title: From nerve net to nerve ring, nerve cord and brain--evolution of the nervous system.
abstract: The puzzle of how complex nervous systems emerged remains unsolved. Comparative studies of neurodevelopment in cnidarians and bilaterians suggest that this process began with distinct integration centres that evolved on opposite ends of an initial nerve net. The 'apical nervous system' controlled general body physiology, and the 'blastoporal nervous system' coordinated feeding movements and locomotion. We propose that expansion, integration and fusion of these centres gave rise to the bilaterian nerve cord and brain.
authors.affiliation: Developmental Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 699117 Heidelberg, Germany.
authors.forename: Detlev
authors.initials: D
authors.lastname: Arendt
authors.affiliation: Max Planck Institute for Brain Research, Max-von-Laue-Strasse 4, 60438 Frankfurt am Main, Germany.
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Tosches
authors.affiliation: Pasteur Institute, 25-28 Rue du Dr Roux, 75015 Paris, France.
authors.forename: Heather
authors.initials: H
authors.lastname: Marlow
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001921:Brain / Q000502:physiology*; D006801:Humans; D009415:Nerve Net / Q000502:physiology*; D009420:Nervous System / Q000503:physiopathology*; D009424:Nervous System Physiological Phenomena; D009474:Neurons / Q000502:physiology