Growing evidence suggests that sex differences in cocaine reward responses are regulated by endogenous gonadal hormones. However, few studies have addressed the role of testosterone on cocaine reward and psychomotor activation. This study aimed to determine whether testosterone influences the development of psychomotor and reward responses to cocaine. Castrated 8-week-old male Fisher rats recei...

BACKGROUND Methadone is widely accepted as the most effective treatment of opioid dependence. However, clinical observations indicate that the medication is less effective in individuals abusing cocaine. Diminished therapeutic efficacy of methadone in cocaine users is intriguing, but its mechanism has not been studied. METHODS Here, the conditioned place preference (CPP) procedure was used to...

In golden hamsters, the expression of a conditioned place preference (CPP) or avoidance (CPA) is regulated in a circadian pattern such that the preference and avoidance are exhibited strongly at the circadian time of prior training, but not at other circadian times. In the rat, reports are conflicting regarding whether time of day learning is evident. We investigated whether this conflict arise...

We showed that rhesus monkeys (Macaca mulatta) can develop a morphine dependence. Rhesus monkeys successfully established a conditioned place preference (CPP) induced by morphine treatment and this preference lasted for at least (36.3 ± 1.3) months. This animal model may be useful for research into addiction in humans.

The aim of the present study was to examine the cross-sensitization induced by prenatal methamphetamine (MA) exposure to challenge dose of cocaine or morphine. Rat mothers received a daily injection of MA (5 mg/kg) or saline throughout the gestation period. Adult male offspring (prenatally MA- or saline-exposed) were divided to groups with challenge doses...

Experiment 1: It is well known that the social context powerfully influences behaviour. Here we examine whether it also influences drug-seeking. Further, acamprosate and naloxone have been discussed to affect different types of craving: acamprosate was reported to affect withdrawalcraving, while naloxone affects reward-craving. Conditioned drug-seeking was modelled using the conditioned place p...

Affective processing, known to influence attention, motivation, and emotional regulation is poorly understood in young children, especially for those with neurodevelopmental disorders characterized by language impairments. Here we faithfully adapt a well-established animal paradigm used for affective processing, conditioned place preference (CPP) for use in typically developing children between...

Most adults consume alcohol with relative impunity, but about 10-20% of users persist (or progress) in their consumption, despite mounting and serious repercussions. Identifying at-risk individuals before neuroadaptative changes associated with chronic use become well ingrained is thus a key step in mitigating and preventing the end stage disease and its devastating impacts. Explaining liabilit...

The rewarding properties of drugs in the mammalian system depend on their ability to activate appetitive motivational states. The associated underlying mechanism is strongly conserved in evolution and invertebrates have recently emerged as a powerful new model in addiction research. The natural reward system in crayfish has surprisingly proven sensitive to human drugs of abuse, providing a new ...

The effects of captopril and Ang II on morphine-induced conditioned place preference (CPP) and morphine self-administration in male Wistar rat were investigated. In CPP experiment, injection of captopril before test significantly decreased the difference of the time spent in compartment A between pre- and post-conditioning compared to morphine group. In self- administration experiment number of...