introduction: it has been shown that orexin peptides have a role in opioid withdrawal behaviors. orexin-expressing neurons that are present in the hypothalamic nuclei send dense projections to the locus coeruleus (lc). withdrawal syndrome is temporally associated with hyperactivity of lc neurons. however, lc neurons do not show withdrawalinduced hyperactivity in the brain slices from morphine-d...

BACKGROUND THE SLEEP SEQUENCE: i) non-REM sleep, ii) REM sleep, and iii) wakefulness, is stable and widely preserved in mammals, but the underlying mechanisms are unknown. It has been shown that this sequence is disrupted by sudden REM sleep onset during active wakefulness (i.e., narcolepsy) in orexin-deficient mutant animals. Phospholipase C (PLC) mediates the signaling of numerous metabotropi...

Insomnia is a common clinical condition characterized by difficulty initiating or maintaining sleep, or non-restorative sleep with impairment of daytime functioning. Currently, treatment for insomnia involves a combination of cognitive behavioral therapy (CBTi) and pharmacological therapy. Among pharmacological interventions, the most evidence exists for benzodiazepine (BZD) receptor agonist dr...

Aim: The effect of orexin on wakefulness has been shown to be largely mediated by activation of histaminergic neurons via orexin receptor-2 (OX2R). Consistently, OX2R mRNA is abundantly expressed in histaminergic neurons in the tuberomammillary nucleus (TMN). However, orexin receptors in the other regions of the brain might also play important roles in maintenance of wakefulness. To dissect the...

NORMAL CARDIOVASCULAR CONTROL is accomplished by a close interplay of homeostatic feedback mechanisms, such as the baroreceptor and chemoreceptor reflexes, and adaptive feedforward mechanisms that allow the organism to adapt to environmental changes and behavioral responses, such as exercise, hunting, fighting, or escape from predators. A hallmark of the adaptive mechanisms is an involvement of...

Dual orexin receptor antagonists (DORAs) are a potential treatment for insomnia that function by blocking both the orexin 1 and orexin 2 receptors. The objective of the current study was to further confirm the impact of therapeutic mechanisms targeting insomnia on locomotor coordination and ethanol interaction using DORAs and gamma-aminobutyric acid (GABA)-A receptor modulators of distinct chem...

Vassalli et al.'s study does not involve or provide additional data regarding influenza virus, influenza vaccines, human samples, animal models of narcolepsy, or experiments related to mimicry and cross-reactivity. They present data on the distribution of hypocretin (HCRT) (also known as orexin) receptors in the brain of an engineered mouse developed by them.

Orexin neuropeptides promote arousal, appetite, reward, and energy expenditure. However, whether orexin affects bone mass accrual is unknown. Here, we show that orexin functions centrally through orexin receptor 2 (OX2R) in the brain to enhance bone formation. OX2R null mice exhibit low bone mass owing to elevated circulating leptin, whereas central administration of an OX2R-selective agonist a...

Orexin/hypocretin neurons have a crucial role in the regulation of sleep and wakefulness. To help determine how these neurons promote wakefulness, we generated transgenic mice in which orexin neurons expressed halorhodopsin (orexin/Halo mice), an orange light-activated neuronal silencer. Slice patch-clamp recordings of orexin neurons that expressed halorhodopsin demonstrated that orange light p...