introduction: it is known that acute and chronic stress induce hormonal and neuronal changes which affecting both pain threshold and nociceptive behaviours. orexin plays an important role in modulation of pain and stress. considering pain modulation during stress and the role of orexin in pain and stress, orexin might be involved in pain modulation during stress.we evaluated the involvement of ...

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...

introduction: orexin-a and b (hypocretin 1 and 2) are neuropeptides that are mostly expressed in the posterior and lateral hypothalamus (lh). intracisternal (icv) and intratechal (it) injections of orexin-a (hypocretin-1) have been shown to elicit analgesic responses in formalin test. however, the locations of central sites that may mediate these effects have not been clearly elucidated. orexin...

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...

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...

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 morphin...

Orexin receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on [43]) are activated endogenous polypeptides orexin-A and orexin-B (also known hypocretin-1 -2; 33 28 aa) derived from a common precursor, preproorexin or orexin proteolytic cleavage some typical peptide modifications [117]. signaling has been associated with regulation of sleep wakefulness, reward addiction, appetite feed...

Orexin neurons (hypocretin neurons) have a critical role in the regulation of sleep/wakefulness, especially in the maintenance of arousal. Here, we revealed that orexin neurons are directly and indirectly activated by orexin via the orexin 2 receptor (OX2R). Orexin B (1 μM) induced depolarization in orexin neurons, which was still observed in the presence of TTX (1 μM), AP-5 (50 μM), and CNQX (...

Introduction: Orexin-A and B (Hypocretin 1 and 2) are neuropeptides that are mostly expressed in the posterior and lateral hypothalamus (LH). Intracisternal (ICV) and intratechal (IT) injections of orexin-A (hypocretin-1) have been shown to elicit analgesic responses in formalin test. However, the locations of central sites that may mediate these effects have not been clearly elucidated. Ore...