Stalking the everted telencephalon: Comparisons of forebrain organization in basal ray-finned fishes and teleosts

Title:
Stalking the everted telencephalon: Comparisons of forebrain organization in basal ray-finned fishes and teleosts
Authors:
Braford, M. R.
Abstract:
Compared to land vertebrates and the other fishes, the basal ray-finned fishes and teleosts have morphologically unusual forebrains. The telencephalic pallium is everted, and its diencephalic inputs arise largely – not from what is clearly the dorsal thalamus but rather – from an enigmatic group of migrated nuclei of the basal diencephalon. The subpallia exhibit much less variation than the pallia. The polypteriforms have a long, thin pallial sheet that can be divided into four zones which recent data suggest could correspond to the ventral, lateral, dorsal, and medial pallia of tetrapods, with some caveats. In sturgeons and gars, the pallium is thicker and divisible into three or four zones. The data available for sturgeons and gars are not sufficient for the formulation of more than a barely working hypothesis, although a review of the existing literature has illuminated some basic unresolved issues in these taxa. The voluminous literature on the pallium of teleosts is briefly summarized. The thickened pallium is divided into four zones which are compared with those of the polypteriforms and those of the tetrapods. The topographical position of the primary olfactory target in the pallium is lateral, which is unexpected in an everted pallium. Several recent hypotheses have sought to explain this organization: partial eversion, caudolateral eversion and displacement, simple eversion with changed olfactory connections, and not quite so simple an eversion with preserved topology. These hypotheses are evaluated and some persisting problems are enumerated.
Citation:
Braford, Mark. 2009. "Stalking the everted telencephalon: Comparisons of forebrain organization in basal ray-finned fishes and teleosts." Brain, Behavior, And Evolution 74: 56-76.
Publisher:
Karger
DATE ISSUED:
2009
Department:
Biology
Type:
article
PUBLISHED VERSION:
10.1159/000229013
PERMANENT LINK:
http://hdl.handle.net/11282/309317

Full metadata record

DC FieldValue Language
dc.contributor.authorBraford, M. R.en_US
dc.date.accessioned2013-12-23T16:07:03Z-
dc.date.available2013-12-23T16:07:03Z-
dc.date.issued2009en
dc.identifier.citationBraford, Mark. 2009. "Stalking the everted telencephalon: Comparisons of forebrain organization in basal ray-finned fishes and teleosts." Brain, Behavior, And Evolution 74: 56-76.en_US
dc.identifier.issn0006-8977en_US
dc.identifier.urihttp://hdl.handle.net/11282/309317-
dc.description.abstractCompared to land vertebrates and the other fishes, the basal ray-finned fishes and teleosts have morphologically unusual forebrains. The telencephalic pallium is everted, and its diencephalic inputs arise largely – not from what is clearly the dorsal thalamus but rather – from an enigmatic group of migrated nuclei of the basal diencephalon. The subpallia exhibit much less variation than the pallia. The polypteriforms have a long, thin pallial sheet that can be divided into four zones which recent data suggest could correspond to the ventral, lateral, dorsal, and medial pallia of tetrapods, with some caveats. In sturgeons and gars, the pallium is thicker and divisible into three or four zones. The data available for sturgeons and gars are not sufficient for the formulation of more than a barely working hypothesis, although a review of the existing literature has illuminated some basic unresolved issues in these taxa. The voluminous literature on the pallium of teleosts is briefly summarized. The thickened pallium is divided into four zones which are compared with those of the polypteriforms and those of the tetrapods. The topographical position of the primary olfactory target in the pallium is lateral, which is unexpected in an everted pallium. Several recent hypotheses have sought to explain this organization: partial eversion, caudolateral eversion and displacement, simple eversion with changed olfactory connections, and not quite so simple an eversion with preserved topology. These hypotheses are evaluated and some persisting problems are enumerated.en_US
dc.language.isonullen
dc.publisherKargeren_US
dc.identifier.doi10.1159/000229013en
dc.subject.departmentBiologyen_US
dc.titleStalking the everted telencephalon: Comparisons of forebrain organization in basal ray-finned fishes and teleostsen_US
dc.typearticleen_US
dc.identifier.journalBrain, Behavior, And Evolutionen_US
dc.identifier.volume74en_US
dc.identifier.startpage56en_US
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