Anxiogenic, orexigenic and metabolic effects of hypothalamic ghrelin

Currie, Paul J.; Grueneisen, Andreas; Wall, D.G.; Sarkodie, Kwaku

doi:10.1016/j.appet.2008.04.062

Cited by 3 publications

(3 citation statements)

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“…Ghrelin was injected over a 1 min period with the injector left in place for an additional 2 min to permit peptide diffusion After injections, the injector was slowly extracted from the guide cannula. Doses were selected based on previously published reports [7–9] and preliminary work in our lab [46]. In repeated measures testing, ghrelin doses were administered in a randomized order.…”

Section: Methodsmentioning

confidence: 99%

Ghrelin is an orexigenic peptide and elicits anxiety-like behaviors following administration into discrete regions of the hypothalamus

Currie

Khelemsky

Rigsbee

et al. 2012

Behavioural Brain Research

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Previous evidence indicates that peripherally administered ghrelin significantly increases corticotropin releasing hormone (CRH) mRNA and serum corticosterone. In addition, intraventricular administration of ghrelin has been reported to elicit anxiety-like behaviors suggesting that the peptide plays a role in mediating neuroendocrine and behavioral responses to stress. In the present study, we characterized the orexigenic, metabolic, and anxiogenic action of ghrelin following microinjection into the arcuate nucleus (ARN), paraventricular nucleus (PVN), perifornical hypothalamus (PFH), and the ventromedial nucleus (VMN). To assess ghrelin’s role in anxiogenic behavior, rats were injected with vehicle or 50–800 pmol of ghrelin and then placed in an elevated plus maze (EPM) for 10 min. Each test was performed as a single trial per animal. In separate behavioral testing we measured the induction of stereotypic behaviors. Doses of 200 pmol or higher administered into the ARN and PVN elicited anxiety-like behaviors, including an increased avoidance of the open arms of the EPM. However, in the PFH and VMN, higher doses of ghrelin (400–800 pmol) were required to induce anxiety. Ghrelin doses as low as 50 pmol stimulated eating and altered energy substrate oxidation (respiratory quotient; RQ) when injected into the ARN and PVN. Injections into the PFH and VMN elicited more modest effects on eating and RQ at doses of 400 pmol or greater. Our findings indicate that regions of the hypothalamus appear to be differentially sensitive and responsive to the feeding-stimulant, metabolic and anxiogenic actions of ghrelin and that the ARN and PVN, in particular, exert a primary role in mediating these effects.

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Section: Methodsmentioning

confidence: 99%

Ghrelin is an orexigenic peptide and elicits anxiety-like behaviors following administration into discrete regions of the hypothalamus

Currie

Khelemsky

Rigsbee

et al. 2012

Behavioural Brain Research

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“…Therefore, ghrelin-stimulated eating prevents the subsequent expression of anxiety-like behavior. Since we have previously reported that ghrelin treatment into the PVN is effective in eliciting open arm avoidance when administered up to 60 min prior to EPM testing (Currie et al, 2008), it is arguable that the lack of effect of ghrelin we observed in the current study was not simply due to the time course of the peptide’s effect. While MRN injection of 8-OH-DPAT also increased food intake, local infusion of the 5-HT 1A agonist elicited an anxiolytic response.…”

Section: Discussionmentioning

confidence: 62%

Midbrain raphe 5-HT_1A receptor activation alters the effects of ghrelin on appetite and performance in the elevated plus maze

et al. 2015

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Prior research suggests that midbrain serotonergic signaling and hypothalamic ghrelinergic signaling both play critical roles in appetitive and emotional behaviors. In the present study, we investigated the effects of median raphe nucleus (MRN) somatodentritic 5-HT1A receptor activation on the feeding-stimulant and anxiogenic action of paraventricular nucleus (PVN) ghrelin. In an initial experiment, adult male Sprague-Dawley rats were injected with either ghrelin (200-800 pmol) into the PVN or 8-OH-DPAT (2.5-10 nmol), a 5-HT1A receptor agonist, into the MRN. Performance on the elevated plus maze (EPM) was then assessed. In separate rats, MRN 8-OH-DPAT (2.5-5 nmol) was administered 5 min prior to PVN injection of ghrelin (400 pmol) followed by EPM testing. The orexigenic effects of MRN 8-OH-DPAT (0.1-1.6 nmol) paired with PVN ghrelin (50 pmol) were also examined. When administered alone into the PVN, ghrelin significantly decreased the number of entries and time spent in the open arms of the EPM. This anxiogenic effect was blocked if rats were allowed to eat immediately after ghrelin administration and then tested in the plus maze. MRN injections of 8-OH-DPAT were anxiolytic, and when rats were pretreated with 8-OH-DPAT prior to ghrelin, the anxiogenic action of the peptide was attenuated. In contrast, MRN administration of 8-OH-DPAT potentiated the eating-stimulant effect of PVN ghrelin. Overall, our findings demonstrate that ghrelinergic and serotonergic circuits interact in the neural control of eating and anxiety-like behaviors, with 5-HT1A receptor mechanisms potentiating the orexigenic action of ghrelin while inhibiting ghrelin-induced anxiogenesis as measured via the EPM.

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“…Ghrelin was isolated from goldfish and it is naturally secreted by stomach and hypothalamic neurons now recognized as a multifunctional peptide for human feeding, cardiovascular and pshycological metabolisms (Currie et al, 2008;Miura et al, 2009). Ghrelin has also electrophysiological effects on pedunculopontine tegmental neurons in rats (Kim et al, 2009).…”

Section: Ghrelinmentioning

confidence: 99%

Fish derived bio-active peptides and their metabolic effects

Altınelataman¹,

Týčová²,

Tsentalovich³

2015

EgeJFAS

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Diğer tüm organizmalar gibi, balıklar da, araştırmalarda antimikrobiyal, antihipertensif, antioksidan ve antitümör aktivitelerine odaklanılan bio-aktif bileşiklerin zengin kaynağıdırlar. Bunlar, sadece yüksek besin değeri nedeniyle değil, özellikle son yirmi yılda geliştirilen analitik yöntemlerle elde edilen peptidleri açısından da kullanılabilirler. Akuatik canlılar dünya üzerinde en fazla tür sayısına sahiptir, dolayısıyla bunlardan bio-aktif peptidlerin eldesi diğerlerine göre oldukça olasıdır ve bu, önceki çalışmalarda açıkça ortaya konmuştur. Doğal peptidler ve uzun zincirli polipeptidlerden uygun enzimatik yöntemlerle elde edilen peptidler tıp alanında yeni ufuklar açabilirler.

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Anxiogenic, orexigenic and metabolic effects of hypothalamic ghrelin

Cited by 3 publications

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Ghrelin is an orexigenic peptide and elicits anxiety-like behaviors following administration into discrete regions of the hypothalamus

Ghrelin is an orexigenic peptide and elicits anxiety-like behaviors following administration into discrete regions of the hypothalamus

Midbrain raphe 5-HT_1A receptor activation alters the effects of ghrelin on appetite and performance in the elevated plus maze

Fish derived bio-active peptides and their metabolic effects

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Anxiogenic, orexigenic and metabolic effects of hypothalamic ghrelin

Cited by 3 publications

References 0 publications

Ghrelin is an orexigenic peptide and elicits anxiety-like behaviors following administration into discrete regions of the hypothalamus

Ghrelin is an orexigenic peptide and elicits anxiety-like behaviors following administration into discrete regions of the hypothalamus

Midbrain raphe 5-HT1A receptor activation alters the effects of ghrelin on appetite and performance in the elevated plus maze

Fish derived bio-active peptides and their metabolic effects

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Midbrain raphe 5-HT_1A receptor activation alters the effects of ghrelin on appetite and performance in the elevated plus maze