The structural organization of the forebrain: a commentary on the papers presented at the 20th Annual Karger Workshop 'Forebrain evolution in fishes'.

During the 2008 Karger Workshop considerable progress was made towards defining a model or structural plan, valid for the prosencephalon of all vertebrates. The presentations demonstrated that the following features, which are valid for tetrapods, also hold true for most groups of fish: (1) The diencephalon proper is clearly composed of three neuromeres, p1-p3; (2) in the pallium four, rather than three, fundamental longitudinal zones can be distinguished; (3) during ontogenesis, numerous GABA-ergic elements migrate tangentially from the subpallium to the pallium. 2009 S. Karger AG, Basel