Córtex cerebral não laminar em peixes teleósteos?

Non-laminar cerebral cortex in teleost fishes?

Hironobu Ito1,* and Naoyuki Yamamoto2

- Author Affiliations

1Department of Anatomy and Neurobiology, Nippon Medical School Tokyo 113-8602, Japan

2Laboratory of Fish Biology, Graduate School of Bioagricultural Sciences, Nagoya University Nagoya 464-8601, Japan

Author for correspondence (hiroito@amber.plala.or.jp)

Abstract

A large skull is disadvantageous to animals that move quickly in three-dimensional space, such as fishes and birds in water or air. A cerebral neocortex with a six-layered sheet has not evolved, most likely due to the limited cranial space. Instead of the laminar cortex, telencephalic nuclear masses seem to have evolved as the pallium in teleost fishes. We consider that the nuclear masses contain rather simple neural circuits sharing a skeleton of simple circuits in the mammalian cortex, which have been elaborated by additional circuits in mammals. Such basic similarities at the connectional level shared by nuclear and cortical pallium might underlie similar or equivalent functions.

Keywords:

cortex pallium evolution actinopterygian teleost

Footnotes

One contribution of 10 to a Special Feature on ‘Brain evolution’.

Received July 17, 2008.

Accepted September 9, 2008.
© 2008 The Royal Society

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