Glutamatergic systems, including AMPA receptors (AMPARs), are involved in opiate-induced neuronal and behavioral plasticity, although the mechanisms underlying these effects are not fully understood. In the present study, we investigated the effects of repeated morphine administration on AMPAR expression, synaptic plasticity, and context-dependent behavioral sensitization to morphine. We found ...

According to memory reconsolidation theory, when long-term memory is reactivated by relevant clues, the memory traces become labile, which can be altered by pharmacological manipulations. Accumulating evidence reveals that memory related to drug abuse can be erased by disrupting reconsolidation process. We used an animal model that could simultaneously measure conditioned hyperactivity and loco...

effects of intra-central amygdala administration of l-arginine, a nitric oxide precursor, and ng-nitro-l-arginine methyl-ester (l name), a nitric oxide synthase inhibitor, on the morphine-induced sensitization and also on the expression of morphine-induced place conditioning in rats were studied. subcutaneous (s.c.) administration of morphine (2.5, 5 and 7.5 mg/kg) induced place conditioning. r...

Orexin plays a crucial role in drug-seeking behavior. The lateral hypothalamus (LH) is a central region that produces orexin, and its projections to the ventral tegmental area (VTA) play an important role in reward and addiction-related behaviors. In this study, we investigated the role of LH stimulation and the involvement of the orexin-1 receptor (Ox1r) in the VTA in relation to morphine sens...

OBJECTIVE In this study, the effects of estradiol valerate and raloxifenea selective estrogen receptor modulator; (SERM) on morphine induced sensitization were examined in mice memory, according to the step-down passive avoidance task. METHOD The mice received morphine or estradiol and raloxifene for three days alone or in combination with morphine. After a drug free period of 5 days, the sub...

This study examined the influence of social isolation on behavioural sensitization to the locomotor effect of morphine and the link between this behaviour and plasma corticosterone concentrations. Four weeks isolation induced an increase in the locomotor effect of morphine. In social and isolated mice, repeated administrations (6) of morphine (one injection every 3 or 4 days) followed by 3 h in...

introduction: topiramate is a newly anti-convulsant drug, which acts as nmda glutamate receptor antagonist as well as the gabab receptor agonist. it is used for physical dependence to opioids as well as cocaine, nicotine, alcohol and ecstasy dependence. in the present study attempts were made to further identification of the effects of topiramate on the acquisition and expression of morphine-in...

Repeated use of drugs of abuse induces permanent changes in the brain that together with environmental factors can promote the development of addiction. Addiction to alcohol or drugs is a chronic disease that is characterized by a compulsion to seek and take the drug, loss of control in limiting intake, continued use despite obvious harm, and recurrent relapses. Behavioral animal models of addi...

Background: Cuminum cyminum fruit essential oil (FEO) dose-dependently can attenuate the expression of morphine tolerance and dependence in morphine-dependent mice. Objective: In this study, the effects of Cuminum cyminum FEO on acquisition and expression of morphine-induced conditioned place preference (CPP) in morphine-sensitized mice were studied. Methods: Repeated subcutaneous (s.c.) adm...

The increasing prescription of opioids is fueling an epidemic of addiction and overdose deaths. Morphine is a highly addictive drug characterized by a high relapse rate - even after a long period of abstinence. Serotonin (5-HT) neurotransmission participates in the development of morphine dependence, as well as the expression of morphine withdrawal. In this study, we examined the effect of bloc...