INTRODUCTION A close interaction exists between the brain opioid and serotonin (5-HT) neurotransmitter systems. Brain neurotransmitter 5-HT plays an important role in the regulation of reward-related processing. However, a few studies have investigated the potential role of 5-HT2A receptors in this behavior. Therefore, the aim of the present study was to assess the influence of morphine and Con...

BACKGROUND Dopamine (DA) and the DA D2 receptor (D2R) are involved in the rewarding and conditioned responses to food and drug rewards. Osborne-Mendel (OM) rats are genetically prone and S5B/P rats are genetically resistant to obesity when fed a high-fat diet. We hypothesized that the differential sensitivity of these two rat strains to natural rewards may also be reflected in sensitivity to dr...

Introduction: The influence of ascorbic acid on the nicotine-induced conditioned place preference (CPP) and behavioral sensitization was investigated in the present study. Methods: In a pilot study, place conditioning and locomotor activity were investigated after nicotine (0.25, 0.5, 0.75, 1, 1.5 and 2 mg/kg) or ascorbic acid (1, 10, 100 and 1000 mg/kg) administration. Different doses of a...

Association between the reward caused by consuming drugs and the context in which they are consumed is essential in the formation of morphine-induced conditioned place preference (CPP). Glucocorticoid receptor (GRs) activation in different regions of the brain affects reward-based reinforcement and memory processing. A wide array of studies have demonstrated that blockage of GRs in some brain a...

We previously developed rat experimental models based on the conditioned place preference (CPP) paradigm in which only four 15-min episodes of dyadic social interaction with a sex- and weight-matched male Sprague Dawley (SD) rat (1) reversed CPP from cocaine to social interaction despite continuing cocaine training, and (2) prevented the reacquisition/re-expression of cocaine CPP. In a concurre...

Objective: Opiate addiction is characterized by compulsive drug use and severe withdrawal symptoms during abstinence. Heantos 4, an herbal pharmacotherapy recently approved for opiate withdrawal treatment in Vietnam, has shown anti-craving properties. The present study is the first preclinical assessment of the effects of Heantos 4 on opiate withdrawal and the rewarding properties of morphine, ...

aptness, defined as how the vehicle is well able to cover the salient features of the tenor (e.g., oil is like liquid gold vs. a train is like a worm), is claimed to be an important factor in the preference for metaphors over similes, or vice versa. this study was an attempt to test for the supposed correlation between the perceived degree of aptness and a priori stylistic preference for metaph...