Previous studies have suggested that Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) can modulate opioid tolerance and dependence via its action on learning and memory. In this study, we examined whether CaMKII could directly regulate opioid tolerance and dependence. CaMKII activity was increased after the treatment with morphine (100 mg/kg s.c. or 75 mg s.c. of morphine/pellet/mouse); t...

The aim of this study was to investigate the effect of ketamine and midazolam on preventing the development of morphine tolerance and dependence and withdrawal syndrome in mice. In the present study different groups of mice were received morphine (50 mg/kg, s.c.), morphine (50 mg/kg, s.c.) + ketamine (25, 50, 75 mg/kg, i.p.) , morphine (50 mg/kg , s.c.) + midazolam (0.5, 1, 2 mg/kg, i.p.) , mor...

Objective(s): Many studies have focused on ventral tegmental area than of other mesocorticolimbic areas, and implicated a key role for the medial prefrontal cortex (mPFC) in the development of addictive behaviors. So far, the role of gamma-aminobutyric acid (GABA) receptors in the discriminative properties of morphine has received little attention and few studies evaluated the role of these rec...

introduction:adenosine as a potent vasodilator has physiological role in regulation of regional cerebral blood flow (rcbf). metod: laser-dِoppler flowmetry technique was used to study pial vessels blood flow responses to adenosine receptors agonists and antagonist. male sprague dawley rats (250-350g) that were housed in standard conditions, were anesthetized with urethane (1.5g/kg). adenosine (g...

Combined use of an opioid with a psychostimulant is popular among drug abusers. Such "polydrug use" may increase drug effects or attenuate adverse effects of either drug alone. We proposed that a combination of methamphetamine (meth) and morphine may change physical opioid withdrawal symptoms. Adult male rats were chronically injected with cumulative subcutaneous (s.c.) doses of morphine, meth ...

The aim of this study was to investigate the effects of magnesium as a N-Methyl–D-Aspartate (NMDA) receptor Antagnist and bromocriptine as a dopamine receptor agonist on morphine dependence and withdrawal symptoms. In the present study different groups of mice were received morphine (50 mg/kg, i.p.) for four days and on fourth day 1.5 hour after the last morphine administration they received di...

Opiates produce significant and persistent changes in synaptic transmission; knowledge of the proteins involved in these changes may help to understand the molecular mechanisms underlying opiate dependence. Using an integrated quantitative proteomics and systems biology approach, we explored changes in the presynaptic protein profile following a paradigm of chronic morphine administration that ...

BACKGROUND Long-term exposure to opiates induces physical dependence; however, the neurobiological mechanisms of this phenomenon are not completely clear. The purpose of this study was to evaluate the effects of systemic and intracerebroventricular (icv) administration of selegiline (a selective inhibitor of monoamine oxidase B) on the morphine withdrawal syndrome in rats. METHODS To this aim...

OBJECTIVE 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 75...

The endogenous opioid system is often assumed to play a role in vulnerability to drug abuse. However, controversial results have been reported regarding the levels of enkephalins or preproenkephalin in neurons of rodent brains after opiate administration. The present study was performed to determine the extracellular levels of enkephalins and its physiological antagonist cholecystokinin (CCK), ...