Fatty acid amide hydrolase (FAAH) inactivation confers enhanced sensitivity to nicotine-induced dopamine release in the mouse nucleus accumbens.

Nicotine exerts its rewarding effects by promoting an increase in dopamine (DA) release in the nucleus accumbens (NAc), and this process is influenced by the endocannabinoid system. Fatty acid amide hydrolase (FAAH) is the main enzyme responsible for the degradation of the endocannabinoid anandamide and other non-cannabinoid N-acylethanolamines. Previous research has reported that both genetic deletion and pharmacological inhibition of FAAH enhance nicotine-induced conditioned place preference at low doses.

Endocannabinoid-mediated synaptic plasticity and addiction-related behavior.

Endogenous cannabinoids (eCBs) are retrograde messengers that provide feedback inhibition of both excitatory and inhibitory transmission in brain through the activation of presynaptic CB₁ receptors. Substantial evidence indicates that eCBs mediate various forms of short- and long-term plasticity in brain regions involved in the etiology of addiction. The present review provides an overview of the mechanisms through which eCBs mediate various forms of synaptic plasticity and discusses evidence that eCB-mediated plasticity is disrupted following exposure to a variety of abused substances that differ substantially in pharmacodynamic mechanism including alcohol, psychostimulants and cannabinoids.

Effects of the mGlu2/3 agonist LY379268 and the mGlu5 antagonist MTEP on ethanol seeking and reinforcement are differentially altered in rats with a history of ethanol dependence.

Background: Growing evidence supports a role of metabotropic glutamate receptors (mGluRs) in ethanol reinforcement, ethanol seeking, and ethanol withdrawal. To extend the understanding of the role of mGluRs in the addiction-relevant effects of ethanol as well as of the treatment target potential of these receptors for alcohol abuse, the effects of a selective mGlu2/3 agonist (LY379268) and a selective mGlu5 antagonist (MTEP) were tested on two processes central to alcohol addiction: ethanol reinforcement and stress-induced reinstatement of ethanol seeking in rats with a history of ethanol dependence.

Methods: Following operant ethanol self-administration training, male Wistar rats were made dependent by intragastric ethanol intubations.

Revisiting intragastric ethanol intubation as a dependence induction method for studies of ethanol reward and motivation in rats.

Background: The purpose of this study was to re-examine intragastric ethanol intubation as a dependence induction method that effectively induces physical dependence upon ethanol over a short time period, is devoid of intrinsic stress artifacts, inexpensive, and easy to implement.

Methods: Male Wistar rats were subjected to ethanol dependence induction via intragastric ethanol intubation. Ethanol solution (final concentration 20%, made up in a dietary liquid vehicle consisting of powdered milk, sucrose, and water) was intubated 4 times per day, at 4-hour intervals, for 6 consecutive days (for a total of 10 g/kg/day).

Comparison of the effects of bupropion and nicotine on locomotor activation and dopamine release in vivo.

Bupropion is an atypical anti-depressant that is approved for smoking cessation. In addition to inhibiting dopamine reuptake, bupropion has been reported to block nicotinic acetylcholine receptors in vitro, and this action might contribute to its efficacy for smoking cessation. In this study we investigated if nicotinic receptor-mediated responses in vivo are decreased in the presence of a behaviorally effective dose of bupropion.

Comparison of the effects of bupropion on nicotinic receptor-evoked [(3)H]dopamine release from rat striatal synaptosomes and slices.

Tobacco smoking is a nicotine addiction, mediated in part by the ability of nicotine to elicit dopamine release, as a result of the stimulation of nicotinic acetylcholine receptors associated with dopaminergic pathways. The smoking cessation agent bupropion is an inhibitor of the dopamine transporter, but has also been shown to inhibit nicotinic acetylcholine receptors. To assess the relative impact of its actions at these two targets, we have examined the effects of bupropion on nicotine-evoked [(3)H]dopamine release from rat striatal synaptosomes and slices, in the absence of any other transporter inhibitor.

Nicotine: from molecular mechanisms to behaviour.

The addictive potential of nicotine is clearly recognized by the tenacity of tobacco smoking for most users, and has prompted extensive psychopharmacological studies in animals. In parallel, the interaction of nicotine with the many subtypes of its eponymous receptor has been the focus of molecular and cellular investigations. More recently, a convergence of these approaches has been stimulated by the generation of transgenic animals, which facilitates analysis of the impact of molecular changes on behaviour.

Investigating the actions of bupropion on dependence-related effects of nicotine in rats.

Rationale: The clinical success of the antidepressant bupropion, marketed as Zyban in smoking cessation, presents an ideal opportunity to unravel its mechanism of action utilising animal models of nicotine dependence.

Objective: The present experiments utilise bupropion as a reference compound to examine putative interactions with stimulus properties of nicotine in rats.

Methods And Results: In male hooded Lister rats, bupropion (10 and 30 mg/kg IP) administered 30 min prior to each intravenous nicotine (0.