introduction: transient receptor potential vanilloid type 1 (trpv1) and protein kinase cγ (pkcγ) are involved in sensitization/desensitization to noxious stimuli. we aimed to examine the gene expression levels of trpv1 and pkcγ in rat lumbosacral cord and midbrain on days 1, 4 and 8 of induction of morphine analgesic tolerance. methods: two groups of male wistar rats received twice daily saline...

Dysregulation of histone modifying enzymes has been associated with numerous psychiatric disorders. Alterations in G9a (Ehmt2), a histone methyltransferase that catalyzes the euchromatic dimethylation of histone H3 at lysine 9 (H3K9me2), has been implicated recently in mediating neural and behavioral plasticity in response to chronic cocaine administration. Here, we show that chronic morphine, ...

The mesocorticolimbic dopaminergic system plays an important role in the reinforcing effects of drugs of abuse, and the activity-dependent synaptic plasticity of the system is involved in drug dependence. A DNA microarray screening revealed that the expression levels of tissue plasminogen activator (tPA) mRNA in the nucleus accumbens of morphine- or methamphetamine-dependent rats were significa...

It has been shown that L-arginine like the abused drugs could release dopamine from meso-cortico-limbic system. The purpose of the present study was to compare the effect of L-arginine with morphine as a standard abuse drug in the induction of conditioned place preference (CPP) in rat. For this purpose, male Wistar rats (250-300 g) were used in the experiments. Five days after surgical cannulat...

Introduction: Regulators of G-protein signaling protein negatively control G protein -coupled receptor signaling duration by accelerating Gα subunit guanosine triphosphate hydrolysis. Since regulator of G-protein signaling4 has an important role in modulating morphine effects at the cellular level and the exact mechanism(s) of adrenalectomy-induced morphine sensitization have not been fully cl...

Extracellular signal-regulated kinase (ERK), a mitogen-activated protein kinase (MAPK), transduces a broad range of extracellular stimuli into diverse intracellular responses. It has been reported that ERK is involved in the modulation of nociceptive information and central sensitization produced by intense noxious stimuli or peripheral tissue inflammation. Our previous studies showed that the ...

introduction: the role of midbrain reticular formation, which includes the nucleus cuneiformis (ncf), as a crucial antinociceptive region in descending pain modulation has long been investigated. in this study, we tried to highlight the role of ncf in morphine-induced antinociception in formalin-induced pain model in rats. methods: a total of 201 male wistar rats weighing 260-310 g were used in...

Adolescence in humans is a vulnerable period for illicit drug use, and teenage onset of drug use is associated with long-term addiction. Adolescent sensitivity to drug reinforcement, relapse, and withdrawal has not been explored thoroughly in animal models, especially considering opiate drugs such as morphine and heroin. The present series of studies profiles adolescent sensitivity to opiates u...