Circadian rhythm influences naloxone induced morphine withdrawal and neuronal activity of lateral paragigantocellularis nucleus.

Investigations have shown that the circadian rhythm can affect the mechanisms associated with drug dependence. In this regard, we sought to assess the negative consequence of morphine withdrawal syndrome on conditioned place aversion (CPA) and lateral paragigantocellularis (LPGi) neuronal activity in morphine-dependent rats during light (8:00-12:00) and dark (20:00-24:00) cycles. Male Wistar rats (250-300 g) were received 10 mg/kg morphine or its vehicle (Saline, 2 mL/kg/12 h, s.

Coregulation of sleep-pain physiological interplay by orexin system: An unprecedented review.

Accumulating evidence support the critical role of endogenous orexin system in modulation of various physiological functions. Among these, regulation of pain and wakefulness have extensively been investigated, however, by independent series of studies each focusing a distinct side. It is now well established that orexins induce potent analgesic effect via affecting their receptors within several specific brain structures.

Intracoerulear microinjection of orexin-A induces morphine withdrawal-like signs in rats.

Orexin (hypocretin) neuropeptides play a pivotal role in expression of opioid withdrawal signs. Hypothalamic orexinergic neurons provide dense afferents for the nucleus locus coeruleus (LC). Somatic signs of opioid withdrawal are associated with the enhanced activity of LC neurons.

The role of orexin type-1 receptors in the development of morphine tolerance in locus coeruleus neurons: An electrophysiological perspective.

Long-term exposure to opioid agonists results in tolerance to their analgesic effects, so the effectiveness of opioid agonists in the management of pain becomes limited. The locus coeruleus (LC) nucleus has been involved in the development of tolerance to opiates. Orexin type-1 receptors (OX1Rs) are highly expressed in LC nucleus.

Blockade of orexin type 1 receptors inhibits the development of morphine tolerance in lateral paragigantocellularis nucleus: an electrophysiological approach.

Repetitive administration of opioid agonists is associated with the development of tolerance to the effects of these substances and limits their application. Orexin (also known as hypocretin) is involved in morphine tolerance and dependence. The lateral paragigantocellularis nucleus (LPGi) is a key brain region implicated in the tolerance and dependence to opiates.

Orexin type 1 receptor antagonism in Lateral Paragigantocellularis nucleus attenuates naloxone precipitated morphine withdrawal symptoms in rats.

Orexin neuropeptides have been reported to be involved in morphine induced physical dependence and withdrawal. The Lateral Paragigantocellularis (LPGi) is a key brain region implicated in the expression of somatic signs of morphine withdrawal syndrome. Orexin A and orexin type 1 receptor have been found in LPGi neurons but the effect of orexin on the expression of opiate dependence and withdrawal phenomena in this brain structure has not been studied yet.