Expression of agouti-related protein (AgRP) in the hypothalamus and adrenal gland of the duck (Anas platyrhynchos)

Mirabella, Nicola; Esposito, Vincenzo; Squillacioti, Caterina; Luca, Arianna De; Paino, G.

doi:10.1007/s00429-004-0431-0

Cited by 10 publications

(10 citation statements)

References 31 publications

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“…AgRP terminals were shown to be widely spread throughout several hypothalamic structures as well as the amygdala, other forebrain regions and brainstem5556. AgRP terminals were also found in the internal layer of the median eminence in rodents5659, the infundibulum in rhesus monkeys60, and the infundibulum and median eminence in ducks61. Those findings suggest that AgRP may also act as a hypophysiotropic factor and thus exert neuroendocrine functions, a potential property of AgRP that has been largely overlooked.…”

Section: Discussionmentioning

confidence: 94%

Novel hypophysiotropic AgRP2 neurons and pineal cells revealed by BAC transgenesis in zebrafish

Shainer

Buchshtab

Hawkins

et al. 2017

Sci Rep

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The neuropeptide agouti-related protein (AgRP) is expressed in the arcuate nucleus of the mammalian hypothalamus and plays a key role in regulating food consumption and energy homeostasis. Fish express two agrp genes in the brain: agrp1, considered functionally homologous with the mammalian AgRP, and agrp2. The role of agrp2 and its relationship to agrp1 are not fully understood. Utilizing BAC transgenesis, we generated transgenic zebrafish in which agrp1- and agrp2-expressing cells can be visualized and manipulated. By characterizing these transgenic lines, we showed that agrp1-expressing neurons are located in the ventral periventricular hypothalamus (the equivalent of the mammalian arcuate nucleus), projecting throughout the hypothalamus and towards the preoptic area. The agrp2 gene was expressed in the pineal gland in a previously uncharacterized subgroup of cells. Additionally, agrp2 was expressed in a small group of neurons in the preoptic area that project directly towards the pituitary and form an interface with the pituitary vasculature, suggesting that preoptic AgRP2 neurons are hypophysiotropic. We showed that direct synaptic connection can exist between AgRP1 and AgRP2 neurons in the hypothalamus, suggesting communication and coordination between AgRP1 and AgRP2 neurons and, therefore, probably also between the processes they regulate.

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Section: Discussionmentioning

confidence: 94%

Novel hypophysiotropic AgRP2 neurons and pineal cells revealed by BAC transgenesis in zebrafish

Shainer

Buchshtab

Hawkins

et al. 2017

Sci Rep

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“…Specificity was determined through preabsorption of the antiserum with the peptide antigen (Légrádi & Lechan, 1999; Nilsson et al, ), following which the authors found no immunolabeling of AgRP in any sections. A single band between 14–21kDa was recognized by this antibody with western blot analysis of total duck brain or hypothalamic tissue extracts (Mirabella, Esposito, Squillacioti, De Luca, & Paino, ).…”

Section: Methodsmentioning

confidence: 99%

Neurotransmitter diversity in pre‐synaptic terminals located in the parvicellular neuroendocrine paraventricular nucleus of the rat and mouse hypothalamus

Johnson

Bains

Watts

2018

J of Comparative Neurology

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Virtually all rodent neuroendocrine corticotropin-releasing-hormone (CRH) neurons are in the dorsal medial parvicellular (mpd) part of the paraventricular nucleus of the hypothalamus (PVH). They form the final common pathway for adrenocortical stress responses. Their activity is controlled by sets of GABA-, glutamate-, and catecholamine-containing inputs arranged in an interactive pre-motor network. Defining the nature and arrangement of these inputs can help clarify how stressor type and intensity information is conveyed to neuroendocrine neurons. Here we use immunohistochemistry with high-resolution 3-dimensional image analyses to examine the arrangement of single- and co-occurring GABA, glutamate, and catecholamine markers in synaptophysin-defined pre-synaptic terminals in the PVHmpd of unstressed rats and Crh-IRES-Cre;Ai14 transgenic mice: respectively, vesicular glutamate transporter 2 (VGluT2), vesicular GABA transporter (VGAT), dopamine β-hydroxylase (DBH), and phenylethanolamine n-methyltransferase (PNMT). Just over half of all PVHmpd pre-synaptic terminals contain VGAT, with slightly less containing VGluT2. The vast majority of terminal appositions with mouse CRH neurons occur non-somatically. However, there are significantly more somatic VGAT than VGluT2 appositions. In the rat PVHmpd, about five times as many pre-synaptic terminals contain PNMT than DBH only. However, because epinephrine release has never been detected in the PVH, PNMT terminals may functionally be noradrenergic not adrenergic. PNMT and VGluT2 co-occur in some pre-synaptic terminals indicating the potential for co-transmission of glutamate and norepinephrine. Collectively, these results provide a structural basis for how GABA/glutamate/catecholamine interactions enable adrenocortical responses to fast-onset interosensory stimuli, and more broadly, how combinations of PVH neurotransmitters and neuromodulators interact dynamically to control adrenocortical activity.

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“…The rabbit AgRP antiserum (Phoenix Pharmacueticals # H-003-53; lot # 00481) was made against a synthetic peptide representing amino acids 83-132-NH 2 from human AgRP and shows no cross-reactivity with ␣-MSH, or mammalian leptin, orexin A/B, neuropeptide Y, or melanocyteconcentrating hormone (MCH) in RIA (manufacturer's technical information). The specificity of this antiserum has also been documented by its detection of a single band of 17 kDa molecular weight by Western blot in brain tissue and by preadsorption with its respective antigen for immunocytochemistry on brain slices (Legradi and Lechan, 1999;Mirabella et al, 2004).…”

Section: Immunocytochemistrymentioning

confidence: 98%

Conserved neurochemical pathways involved in hypothalamic control of energy homeostasis

Forlano

Cone

2007

J of Comparative Neurology

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The melanocortin system, which includes alpha-melanocyte-stimulating hormone (alpha-MSH) and its endogenous antagonist, agouti-related protein (AgRP), is fundamental for the central control of energy homeostasis in mammals. Recent studies have demonstrated that many neuropeptides involved in the control of ingestive behavior and energy expenditure, including melanocortins, are also expressed and functional in teleost fishes. To test the hypothesis that the underlying neural pathways involved in energy homeostasis are conserved throughout vertebrate evolution, the neuroanatomical distribution of alpha-MSH in relation to AgRP was mapped in a teleost (zebrafish, Danio rerio) by double-label immunocytochemistry. Zebrafish alpha-MSH- and AgRP-immunoreactive (ir) cells are found in discrete populations in the ventral periventricular hypothalamus, the proposed arcuate homologue in teleosts. Major ascending projections are similar for both peptides, and dense ir-fibers innervate preoptic and ventral telencephalic nuclei homologous to paraventricular, lateral septal, and amygdala nuclei in mammals. Furthermore, alpha-MSH and AgRP-ir somata and fibers are pronounced at 5 days post fertilization when yolk reserves are depleted and larvae begin to feed actively, which supports the functional significance of these peptides for feeding behavior. The conservation of melanocortin peptide function and projection pathways further support zebrafish as an excellent genetic model system to investigate basic mechanisms involved in the central regulation of energy homeostasis.

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Expression of agouti-related protein (AgRP) in the hypothalamus and adrenal gland of the duck (Anas platyrhynchos)

Cited by 10 publications

References 31 publications

Novel hypophysiotropic AgRP2 neurons and pineal cells revealed by BAC transgenesis in zebrafish

Novel hypophysiotropic AgRP2 neurons and pineal cells revealed by BAC transgenesis in zebrafish

Neurotransmitter diversity in pre‐synaptic terminals located in the parvicellular neuroendocrine paraventricular nucleus of the rat and mouse hypothalamus

Conserved neurochemical pathways involved in hypothalamic control of energy homeostasis

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