background and objectives cannabinoids which are active compounds of marijuana show some pharmacological effects similar to the opioids. there are also functional interactions between both cannabinoid and opioid systems. in this study we investigated the role of cannabinoid receptors in central amygdala and its interaction with opioid system.   methods in the present study, we investigated the ...

Application of low concentrations (pu-nu) of NGF to mouse dorsal root ganglion (DRG)-spinal cord explants in long-term organotypic cultures rapidly prolongs the duration of the Ca2+-dependent component of the action potential (APD) in a major subset of DRG neurons that were previously shown to have characteristic responsiveness to exogenous opioids. These NGF-elicited excitatory modulating effe...

one of the main components of the stress system is hypothalamus- pituitary-adrenal (hpa) axis. acute activation of µ-opioid receptors increases the activity of the hpa axis, leading to release of acth and corticosterone. glucocorticoids can change behaviors, depend on age but there were no evidences about the interaction between age, opioid system and glucocorticoids. in this experiment, effect...

In the present study, interactions of dopamine receptor agonists and antagonists with water swimming stress (WSS) on naloxone-induced jumping in morphine-dependent mice were examined. Mice were rendered dependent as described in the methods section. The opioid receptor antagonist, naloxone (1 mg/kg), was injected to elicit jumping (as a withdrawal sign). The first group exposed to WSS in the pr...

Local analgesic effects of exogenous opioid agonists are particularly prominent in painful inflammatory conditions and are mediated by opioid receptors on peripheral sensory nerves. The endogenous ligands of these receptors, opioid peptides, have been demonstrated in resident immune cells within inflamed tissue of animals and humans. Here we examine in vivo and in vitro whether interleukin 1 be...

Opioids have been previously shown to confer short-term cardioprotection against a prolonged ischemic insult. Therefore, the present study was designed to determine whether opioids can induce a delayed or "second window" of cardioprotection and to assess the potential involvement of the mitochondrial KATP channel. All rats were subjected to 30 minutes of ischemia and 2 hours of reperfusion (I/R...

The parafascicular nucleus (PFN) of thalamus, as a supraspinal structure, has an important role in processing of nociceptive information. In addition, μ-opioid receptor contributes to supraspinal modulation of nociception. In the present study, the effects of microinjection of naloxone (a non-specific opioid-receptor antagonist) and naloxonazine (a specific μ-opioid receptor antagonist) were in...

Spinal cord neurons can support a simple form of instrumental learning. In this paradigm, rats completely transected at the second thoracic vertebra learn to minimize shock exposure by maintaining a hindlimb in a flexed position. Prior exposure to uncontrollable shock (shock independent of leg position) disrupts this learning. This learning deficit lasts for at least 24h and depends on the NMDA...

In the present study, interactions of dopamine receptor agonists and antagonists with water swimming stress (WSS) on naloxone-induced jumping in morphine-dependent mice were examined. Mice were rendered dependent as described in the methods section. The opioid receptor antagonist, naloxone (1 mg/kg), was injected to elicit jumping (as a withdrawal sign). The first group exposed to WSS in the pr...