Revised nomenclature for avian telencephalon and some related brainstem nuclei.
Abstract
The standard nomenclature that has been used for many telencephalic and related brainstem
structures in birds is based on flawed assumptions of homology to mammals. In particular,
the outdated terminology implies that most of the avian telencephalon is a hypertrophied
basal ganglia, when it is now clear that most of the avian telencephalon is neurochemically,
hodologically, and functionally comparable to the mammalian neocortex, claustrum,
and pallial amygdala (all of which derive from the pallial sector of the developing
telencephalon). Recognizing that this promotes misunderstanding of the functional
organization of avian brains and their evolutionary relationship to mammalian brains,
avian brain specialists began discussions to rectify this problem, culminating in
the Avian Brain Nomenclature Forum held at Duke University in July 2002, which approved
a new terminology for avian telencephalon and some allied brainstem cell groups. Details
of this new terminology are presented here, as is a rationale for each name change
and evidence for any homologies implied by the new names. Revisions for the brainstem
focused on vocal control, catecholaminergic, cholinergic, and basal ganglia-related
nuclei. For example, the Forum recognized that the hypoglossal nucleus had been incorrectly
identified as the nucleus intermedius in the Karten and Hodos (1967) pigeon brain
atlas, and what was identified as the hypoglossal nucleus in that atlas should instead
be called the supraspinal nucleus. The locus ceruleus of this and other avian atlases
was noted to consist of a caudal noradrenergic part homologous to the mammalian locus
coeruleus and a rostral region corresponding to the mammalian A8 dopaminergic cell
group. The midbrain dopaminergic cell group in birds known as the nucleus tegmenti
pedunculopontinus pars compacta was recognized as homologous to the mammalian substantia
nigra pars compacta and was renamed accordingly; a group of gamma-aminobutyric acid
(GABA)ergic neurons at the lateral edge of this region was identified as homologous
to the mammalian substantia nigra pars reticulata and was also renamed accordingly.
A field of cholinergic neurons in the rostral avian hindbrain was named the nucleus
pedunculopontinus tegmenti, whereas the anterior nucleus of the ansa lenticularis
in the avian diencephalon was renamed the subthalamic nucleus, both for their evident
mammalian homologues. For the basal (i.e., subpallial) telencephalon, the actual parts
of the basal ganglia were given names reflecting their now evident homologues. For
example, the lobus parolfactorius and paleostriatum augmentatum were acknowledged
to make up the dorsal subdivision of the striatal part of the basal ganglia and were
renamed as the medial and lateral striatum. The paleostriatum primitivum was recognized
as homologous to the mammalian globus pallidus and renamed as such. Additionally,
the rostroventral part of what was called the lobus parolfactorius was acknowledged
as comparable to the mammalian nucleus accumbens, which, together with the olfactory
tubercle, was noted to be part of the ventral striatum in birds. A ventral pallidum,
a basal cholinergic cell group, and medial and lateral bed nuclei of the stria terminalis
were also recognized. The dorsal (i.e., pallial) telencephalic regions that had been
erroneously named to reflect presumed homology to striatal parts of mammalian basal
ganglia were renamed as part of the pallium, using prefixes that retain most established
abbreviations, to maintain continuity with the outdated nomenclature. We concluded,
however, that one-to-one (i.e., discrete) homologies with mammals are still uncertain
for most of the telencephalic pallium in birds and thus the new pallial terminology
is largely devoid of assumptions of one-to-one homologies with mammals. The sectors
of the hyperstriatum composing the Wulst (i.e., the hyperstriatum accessorium intermedium,
and dorsale), the hyperstriatum ventrale, the neostriatum, and the archistriatum have
been renamed (respectively) the hyperpallium (hypertrophied pallium), the mesopallium
(middle pallium), the nidopallium (nest pallium), and the arcopallium (arched pallium).
The posterior part of the archistriatum has been renamed the posterior pallial amygdala,
the nucleus taeniae recognized as part of the avian amygdala, and a region inferior
to the posterior paleostriatum primitivum included as a subpallial part of the avian
amygdala. The names of some of the laminae and fiber tracts were also changed to reflect
current understanding of the location of pallial and subpallial sectors of the avian
telencephalon. Notably, the lamina medularis dorsalis has been renamed the pallial-subpallial
lamina. We urge all to use this new terminology, because we believe it will promote
better communication among neuroscientists. Further information is available at http://avianbrain.org
Type
Journal articleSubject
AnimalsBirds
Brain Stem
Histological Techniques
Immunohistochemistry
Rats
Telencephalon
Terminology as Topic
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https://hdl.handle.net/10161/11232Published Version (Please cite this version)
10.1002/cne.20118Publication Info
Reiner, Anton; Perkel, David J; Bruce, Laura L; Butler, Ann B; Csillag, András; Kuenzel,
Wayne; ... Avian Brain Nomenclature Forum (2004). Revised nomenclature for avian telencephalon and some related brainstem nuclei. J Comp Neurol, 473(3). pp. 377-414. 10.1002/cne.20118. Retrieved from https://hdl.handle.net/10161/11232.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Erich David Jarvis
Adjunct Professor in the Deptartment of Neurobiology
Dr. Jarvis' laboratory studies the neurobiology of vocal communication. Emphasis is
placed on the molecular pathways involved in the perception and production of learned
vocalizations. They use an integrative approach that combines behavioral, anatomical,
electrophysiological and molecular biological techniques. The main animal model used
is songbirds, one of the few vertebrate groups that evolved the ability to learn vocalizations.
The generality of the discoveries is tested in other vocal lear

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