Opioids are effective analgesic agents but serious adverse effects such as tolerance and withdrawal contribute to opioid dependence and limit their use. Opioid withdrawal involves numerous brain regions and includes suppression of dopamine release and activation of neurons in the ventral striatum. By contrast, acute opioids increase dopamine release. Like withdrawal, acute opioids also activate...

A major obstacle in treating drug addiction is the severity of opiate withdrawal syndrome, which can lead to unwanted relapse. Mitragynine is the major alkaloid compound found in leaves of Mitragyna speciosa, a plant widely used by opiate addicts to mitigate the harshness of drug withdrawal. A series of experiments was conducted to investigate the effect of mitragynine on anxiety behavior, cort...

Glucocorticoid hormones evidently affect memory. Morphine withdrawal causes a cognitive deficit and an increase in corticosterone secretion. In the present study brain corticosterone concentrations were determined after morphine withdrawal. Male mice were made dependent by increasing doses of morphine over 3 days. Blood and brain samples were collected following withdrawal induced by injection ...

previous reports showed that elevated levels of glucocorticoids following morphine withdrawal play an important role in memory impairment. in addition, glucocorticoid receptor (gr) inhibitors improved memory perfor-mance in morphine withdrawal mice. since mineralocorticoid receptor (mr) and grs complement each other, the aim of the current study was to evaluate the effects of spironolactone on ...

In this study, we investigated the effects of acute morphine administration, chronic intermittent escalating-dose morphine administration and spontaneous withdrawal from chronic morphine on mRNA levels of mu opioid receptor (MOP-r), and the opioid peptides pro-opiomelanocortin (POMC) and preprodynorphin (ppDyn) in several key brain regions of the rat, associated with drug reward and motivated b...

Chronic morphine treatment and naloxone precipitated morphine withdrawal activates stress-related brain circuit and results in significant changes in food intake, body weight gain and energy metabolism. The present study aimed to reveal hypothalamic mechanisms underlying these effects. Adult male rats were made dependent on morphine by subcutaneous implantation of constant release drug pellets....

BACKGROUND/AIM Treating animals repeatedly with intermittent and increasing morphine doses has been suggested to allow some withdrawal during each dosing interval, which causes repeated stress. The present study aimed to test this hypothesis and assess sex-related differences in withdrawal signs and their suppression by clonidine. MATERIALS AND METHODS Male and female rats and mice were admin...

A number of experimental studies have found that reactive oxygen species are involved during morphine treatment or withdrawal. The aims of this study were to analyse whether morphine administration and/or removal are related to peroxide generation and/or signs of withdrawal in rats, and whether the changes in antioxidant status induced by the administration of an antioxidant may modify peroxide...

AIM To investigate the effects of morphine dependence and withdrawal on the concentrations of neurosteroids in rat brain. METHODS A method of simultaneous quantification of neurosteroids by gas chromatography-mass spectrometry (GC-MS) had been established. RESULTS The chronic morphine administration (ip) resulted in a marked decrease in the brain concentrations of pregnenolone (PREG), proge...