Previous reports utilizing pharmacological antagonists implicate kainate receptor (KAR) activation in the development of morphine tolerance, dependence, conditioned place preference (CPP), and locomotor sensitization, but the role of glutamate receptor (GluR) 5-containing KAR in these effects remains unclear because of limited selectivity of the inhibitors employed. Therefore, we examined respo...

Chronic morphine administration increases levels of adenylyl cyclase and cAMP-dependent protein kinase (PKA) activity in the locus coeruleus (LC), which contributes to the severalfold activation of LC neurons that occurs during opiate withdrawal. A role for the transcription factor cAMP response element-binding protein (CREB) in mediating the opiate-induced upregulation of the cAMP pathway has ...

Abstract Background and Objective: According to the issue of dependence and tolerance in addicted patients, the inefficiency of existing treatments and the new recommendation for drug combination therapy for diseases in modern pharmacology, the present study examined the effect of methadone and valproate combination on morphine dependence and tolerance. Materials and Methods: Ninety-eight male ...

BACKGROUND Exercise deprivation has been concluded to have some negative effectson psychological well-being. This study was conducted to find outwhether exercise deprivation may lead to morphine dependence in rats. METHODS Forty male Wistar rats weighing 162 ± 9 g were housed in clear plasticcages in groups of two under standard laboratory conditions. The studyhad two phases. In phase I, the ...

The cholinergic system has been proposed to participate in the development of dependence on opioids. The present study examined effects of dermal pretreatment with methyl parathion (MP), an acetylcholinesterase inhibitor, on the development of physical dependence on morphine. Opioid dependence was induced by continuous intracerebroventricular (i.c.v.) infusion of morphine (26 nmol/μl/h) for 3 d...

Opioids are powerful pain relievers, but also potent inducers of dependence and tolerance. Chronic morphine administration (via subcutaneous pellet) induces morphine dependence in the nucleus accumbens, an important dependence region in the brain, yet the cellular mechanisms are mostly unknown. Toll-like receptor 2 (TLR2) plays an essential function in controlling innate and inflammatory respon...

Exposure to opiates such as morphine can lead to psychological and physical dependence in both adult and infant humans. Infant rats experience opiate withdrawal behaviors that are qualitatively different from the withdrawal behaviors displayed by adult rats. In the adult, withdrawal is largely mediated by the mu-opioid receptor. We sought to understand more about what role each opioid receptor ...

Chronic opiate administration results in the development of tolerance and dependence, but the regulation of mu opioid receptor function during this process is not clearly understood. To localize changes in mu opioid receptor-coupled G-protein activity in various brain regions after chronic morphine treatment, the present study examined mu opioid agonist-stimulated [35S]GTPgammaS binding to brai...

BACKGROUND Morphine has been widely used as a clinical anesthetic and analgesic. However, abuse of morphine might result in psychological and physiological dependence. Previous studies have indicated that memory mechanisms play critical roles in morphine dependence. METHODS Morphine dependence was established in mice utilizing place preference conditioning (CPP). We observed changes in the me...