Nuclear parcellation and numbers of orexinergic neurons in five species of larger brained birds

© 2024 The Authors. The Journal of Comparative Neurology published by Wiley Periodicals LLC..

The orexinergic/hypocretinergic system, while having several roles, appears to be a key link in the balance between arousal and food intake. In birds, to date, this system has only been examined anatomically in four species, all with brains smaller than 3.5 g and of limited phylogenetic range. Here, using orexin-A immunohistochemistry, we describe the distribution, morphology, and nuclear parcellation of orexinergic neurons within the hypothalami of a Congo gray and a Timneh gray parrot, a pied crow, an emu, and a common ostrich. These birds represent a broad phylogeny, with brains ranging in size from 7.85 to 26.5 g. Within the hypothalami of the species studied, the orexinergic neurons were organized in two clusters, and a densely packed paraventricular hypothalamic nucleus cluster located within the medial hypothalamus (Hyp), but not contacting the ventricle, and a more loosely packed lateral hypothalamic cluster in the lateral Hyp. Stereological analysis revealed a strong correlation, using phylogenetic generalized least squares regression analyses, between brain mass and the total number of orexinergic neurons, as well as soma parameters such as volume and area. Orexinergic axonal terminals evinced two types of boutons, larger and the smaller en passant boutons. Unlike the orexinergic system in mammals, which has several variances in cluster organization, that of the birds studied, in the present and previous studies, currently shows organizational invariance, despite the differences in brain and body mass, phylogenetic relationships, and life-histories of the species studied.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:532

Enthalten in:

The Journal of comparative neurology - 532(2024), 3 vom: 26. März, Seite e25602

Sprache:

Englisch

Beteiligte Personen:

Mazengenya, Pedzisai [VerfasserIn]
Spocter, Muhammad A [VerfasserIn]
Manger, Paul R [VerfasserIn]

Links:

Volltext

Themen:

Aves
Hypocretin
Immunohistochemistry
Journal Article
Neuropeptides
Orexin
Orexins
RRID:AB_91545
Research Support, Non-U.S. Gov't
Stereology

Anmerkungen:

Date Completed 15.03.2024

Date Revised 26.04.2024

published: Print

Citation Status MEDLINE

doi:

10.1002/cne.25602

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM369727029