Orexins A and B are hypothalamic peptides which are derived from the proteolytic cleavage of prepro-orexin and act via two subtypes of receptors, named OX1-R (that almost exclusively binds orexin-A) and OX2-R (nonselective for both orexins). Several lines of evidence show that other neuropeptides, which like orexins are involved in the central control of energy homeostasis (e.g. leptin and ghre...

Recently, overlapping molecular phenotypes of hematopoietic and neuropoietic cells were described in mice. Here, we examined primary human CD34(+) hematopoietic stem and progenitor cells applying specialized cDNA arrays, real-time reverse-transcriptase-polymerase chain reaction (RT-PCR), and fluorescent-activated cell sorter (FACS) analysis focusing on genes involved in neurobiologic functions....

introduction: the functional effects of orexin-b on the calcium spikes and excitability of the neuronal soma membrane of garden snail, helix aspersa were studied. methods: conventional intracellular recording, under the current clamp conditions was performed to examine the effects of orexin-b on the configuration and electrophysiological properties of calcium spikes. results: application of ore...

Initial research on the functional significance of two novel hypothalamic neuropeptides, orexin-A and orexin-B, suggested an important role in appetite regulation. Since then, however, these peptides have also been shown to influence a wide range of other physiological and behavioural processes. In this paper, we review the now quite extensive literature on orexins and appetite control, and con...

The orexin/hypocretin system is involved in multiple cocaine addiction processes that involve drug-associated environmental cues, including cue-induced reinstatement of extinguished cocaine seeking and expression of conditioned place preference. However, the orexin system does not play a role in several behaviors that are less cue-dependent, such as cocaine-primed reinstatement of extinguished ...

OBJECTIVES Orexins A and B are neuropeptides involved in the regulation of feeding behavior, energy homeostasis and arousal. In the human retina, however, immunohistochemical localization of orexins and their receptors, OX-R1 and OX-R2, has not been ascertained. METHODS We localized orexins A and B, OX-R1 and OX-R2 in the human retina using immunohistochemistry. Retinae from 2 Alzheimer's dis...

The orexins [orexin A (OXA) and orexin B (OXB)] are novel neuropeptides that increase food intake in rodents. The aim of this study was to determine the distribution of orexin and orexin receptors (OX1R and OX2R) in the rat duodenum and examine the effects of intravenous orexin on fasting gut motility. OXA-like immunoreactivity was found in varicose nerve fibers in myenteric and submucosal gang...

Introduction: Orexin-containing neurons exist in the lateral hypothalamic region, sending their projections toward mesolimbic regions such as the Ventral Tegmental Area (VTA). Methods: In the current study, a Reinstatement model is used to examine the effects of intra-VTA administration of SB334867 as an Orexin-1 Receptor (OX1R) antagonist on drug priming- and Forced Swim Stress (FSS)-induced ...

An enantioselective synthesis of almorexant, a potent antagonist of human orexin receptors, is presented. The chiral tetrahydroisoquinoline core structure was prepared via iridium-catalysed asymmetric intramolecular allylic amidation. Further key catalytic steps of the synthesis include an oxidative Heck reaction at room temperature and a hydrazine-mediated organocatalysed reduction.

Orexin neurons in the lateral hypothalamus (LH)/perifornical area (PFA) are known to promote food intake as well as provide excitatory influence on the dopaminergic reward pathway. Dopamine (DA), in turn, inhibits the reward pathway and food intake through its action in the LH/PFA. However, the cellular mechanism by which DA modulates orexin neurons remains largely unknown. Therefore, we examin...