Larval and adult brains 1

  title={Larval and adult brains 1},
  author={Claus Nielsen},
  journal={Evolution \& Development},
  • C. Nielsen
  • Published 1 September 2005
  • Biology
  • Evolution & Development
Summary Apical organs are a well‐known structure in almost all ciliated eumetazoan larvae, although their function is poorly known. A review of the literature indicates that this small ganglion is the “brain” of the early larva, and it seems probable that it represents the brain of the ancestral, holopelagic ancestor of all eumetazoans, the gastraea. This early brain is lost before or at metamorphosis in all groups. Protostomes (excluding phoronids and brachiopods) appear to have brains of dual… 

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