Details

Autor(en) / Beteiligte

• Oddes, Demi
• Ngwenya, Ayanda
• Malungo, Illke B.
• Burkevica, Anita
• Hård, Therese
• Bertelsen, Mads. F.
• Spocter, Muhammad A.
• Scantlebury, D. Michael
• Manger, Paul R.

Titel

Orexinergic neurons in the hypothalami of an Asiatic lion, an African lion, and a Southeast African cheetah

Ist Teil von

• Journal of comparative neurology (1911), 2023-02, Vol.531 (3), p.366-389

Ort / Verlag

United States: Wiley Subscription Services, Inc

Erscheinungsjahr

2023

Quelle

MEDLINE

Beschreibungen/Notizen

• Employing orexin‐A immunohistochemistry, we describe the distribution, morphology, and nuclear parcellation of orexinergic neurons within the hypothalami of an Asiatic lion (Panthera leo subsp. persica), an African lion (Panthera leo subsp. melanochaita), and a Southeast African cheetah (Acinonyx jubatus subsp. jubatus). In all three felids, the clustering of large, bipolar, and multipolar hypothalamic orexinergic neurons primarily follows the pattern observed in other mammals. The orexinergic neurons were found, primarily, to form three distinct clusters—the main, zona incerta, and optic tract clusters. In addition, large orexinergic neurons were observed in the ventromedial supraoptic region of the hypothalamus, where they are not typically observed in other species. As has been observed in cetartiodactyls and the African elephant, a cluster of small, multipolar orexinergic neurons, the parvocellular cluster, was observed in the medial zone of the hypothalamus in all three felids, although this parvocellular cluster has not been reported in other carnivores. In both subspecies of lions, but not the cheetah, potential orexin‐immunopositive neurons were observed in the paraventricular hypothalamic nucleus, supraoptic nucleus, the lateral part of the retrochiasmatic area, and the inner layer of the median eminence. The distribution and parcellation of orexinergic neurons in the hypothalami of the three felids studied appear to be more complex than observed in many other mammals and for the two subspecies of lion may be even more complex. These findings are discussed in terms of potential technical concerns, phylogenetic variations of this system, and potentially associated functional aspects of the orexinergic system. Photomicrograph of orexinergic neurons forming the main orexinergic neuronal cluster in the hypothalamus of a Southeast African cheetah. While showing the standard features of the orexinergic system, the Southeast African cheetah, along with an Asiatic and an African lion, also exhibits specializations in the organization of this system. This has implications for sleep and arousal in these large carnivores.