the amygdala is a forebrain region, which is known as a modulator of pain sensation. the amygdala, particularly the central nucleus, has high concentrations of enkephalins relative to dynorphins and has high concentrations of opioid receptors. we here studied the role of central nuclei of amygdala in morphine antinociception. methods: in this study, we used 130 male wistar rats (200- 250g). bil...

Introduction: According to previous studies, colchicine causes neuronal destruction and learning depression. In this project, effects of colchicine injection into the CA1 and interaction between colchicine and nitric oxide (NO) in this area on the expression of drug-seeking behavior were investigated. Methods: Wistar rats (250-300 g) were bilaterally cannulated at the CA1 area. Colchicine (2...

Opioids, acting at μ opioid receptors, are commonly used for pain management. Chronic opioid treatment induces cellular adaptations, which trigger long-term side effects, including constipation mediated by enteric neurons. We tested the hypothesis that chronic opioid treatment induces alterations of μ opioid receptor signaling in enteric neurons, which are likely to serve as mechanisms underlyi...

Acute morphine withdrawal is considered to be the physical manifestation of dependence, emerging when morphine administration is stopped or after the administration of an opiate antagonist, such as naloxone. Gabapentin, which is an antiepileptic, agent, enhances the analgesic effect of morphine in healthy volunteers, but its effect on morphine dependence and withdrawal signs has not determined ...

BACKGROUND Morphine induces myocardial preconditioning (M-PC) via activation of mitochondrial large conductance Ca2+-sensitive potassium (mKCa) channels. An upstream regulator of mKCa channels is protein kinase A (PKA). Furthermore, mKCa channel activation regulates mitochondrial bioenergetics and thereby prevents opening of the mitochondrial permeability transition pore (mPTP). Here, we invest...

Some studies have shown that acetylcholine muscarinic receptors involved in the opiate reward. In the present study, the effect of intra-basolateral amygdale (BLA) acetylcholine muscarinic like receptor agonist (physostigmine) and antagonist (atropine) on the acquisition of morphine-induced place preference has been investigated in male Wistar rats. For this purpose, two 22 gauges guide cannula...

objectives: dependence and tolerance are major restricting factors in the clinical use of opioid analgesics. in the present study, the effects of thymoquinone, the major constituent of nigella sativa seeds, on morphine dependence and tolerance were investigated in mice. materials and methods: male adult nmri mice were made tolerant and dependent by repeated injections of morphine (50, 50, and 7...

Two morphine prodrugs ('PDA' and 'PDB') were synthesized and the kinetics of esterase-mediated morphine release from these prodrugs were determined when incubated with plasma from different animal species. Morphine was rapidly released from PDA by all species plasma with the maximum reached within 5-10min; the released morphine was biologically active as determined by an in vitro cAMP assay. Th...