TY - JOUR
T1 - Distribution of orexin/hypocretin immunoreactivity in the brain of a male songbird, the house finch, Carpodacus mexicanus (DOI:10.1016/j.jchemneu.2006.05.003)
AU - Singletary, Kristan G.
AU - Deviche, Pierre
AU - Strand, Christine
AU - Delville, Yvon
N1 - Funding Information:
The present work was supported by ES10385 from the NIH and IOB0516272 from the NSF awarded to YD. KGS was supported by a Neuroscience Graduate Fellowship from the Institute for Neuroscience at the University of Texas. We would like to thank Mimi Huang and Geri Vine for their excellent technical assistance.
PY - 2007/3
Y1 - 2007/3
N2 - Previous research has shown orexin/hypocretin immunoreactive (orexin-ir) neurons in domesticated Galliformes. However, these findings may not be representative of other birds and these studies did not include a distribution of orexin-ir projections throughout the brain. The present study was carried out in a wild-caught passerine, the house finch, Carpodacus mexicanus, and includes a detailed description of orexin-ir neurons and their projections. Orexin A and B-ir neurons were located in a single population centered on the paraventricular nucleus of the hypothalamus extending into the lateral hypothalamic area, consistent with other studies in birds. Orexin A and B-ir fibers were similarly visible across the brain, with the highest density within the preoptic area, hypothalamus and thalamus. Orexin-ir projections extended from the paraventricular nucleus rostrally to the preoptic area, laterally towards the medial striatum, nidopallium, and dorsally along the lateral ventricle towards the mesopallium. Caudally, the highest densities of orexin-ir fibers were found along the third ventricle. The periaqueductal grey, substantia nigra pars compacta and the locus coeruleus also showed a high density of orexin-ir fibers. This study showed a detailed fiber distribution previously unreported in birds and showed that orexin-ir neurons were located in similar areas regardless of phylogeny or domestication in birds. The apparently conserved neural distribution of orexins suggests that these peptides play similar roles among birds. The widespread distribution of the projections in brain areas serving various roles indicates the potential involvement of these peptides in multiple behavioral and physiological functions.
AB - Previous research has shown orexin/hypocretin immunoreactive (orexin-ir) neurons in domesticated Galliformes. However, these findings may not be representative of other birds and these studies did not include a distribution of orexin-ir projections throughout the brain. The present study was carried out in a wild-caught passerine, the house finch, Carpodacus mexicanus, and includes a detailed description of orexin-ir neurons and their projections. Orexin A and B-ir neurons were located in a single population centered on the paraventricular nucleus of the hypothalamus extending into the lateral hypothalamic area, consistent with other studies in birds. Orexin A and B-ir fibers were similarly visible across the brain, with the highest density within the preoptic area, hypothalamus and thalamus. Orexin-ir projections extended from the paraventricular nucleus rostrally to the preoptic area, laterally towards the medial striatum, nidopallium, and dorsally along the lateral ventricle towards the mesopallium. Caudally, the highest densities of orexin-ir fibers were found along the third ventricle. The periaqueductal grey, substantia nigra pars compacta and the locus coeruleus also showed a high density of orexin-ir fibers. This study showed a detailed fiber distribution previously unreported in birds and showed that orexin-ir neurons were located in similar areas regardless of phylogeny or domestication in birds. The apparently conserved neural distribution of orexins suggests that these peptides play similar roles among birds. The widespread distribution of the projections in brain areas serving various roles indicates the potential involvement of these peptides in multiple behavioral and physiological functions.
KW - Birds
KW - Comparative neuroanatomy
KW - Hypothalamus
KW - Neuropeptide
KW - Paraventricular nucleus
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U2 - 10.1016/j.jchemneu.2006.12.002
DO - 10.1016/j.jchemneu.2006.12.002
M3 - Comment/debate
AN - SCOPUS:33847687177
SN - 0891-0618
VL - 33
SP - 101
EP - 109
JO - Journal of Chemical Neuroanatomy
JF - Journal of Chemical Neuroanatomy
IS - 2
ER -