Emilio Ambrosio

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Much research supports a link between stress and its concomitant hypothalamic-pituitary-adrenal (HPA) axis responses with behavioral sensitivity to psychoactive drugs. Our research demonstrates that Lewis inbred rats more readily acquire drug self-administration than Fischer 344 (F344) inbred rats and, compared to this strain, Lewis rats have hyporesponsive(More)
Opiates and cannabinoids are among the most widely consumed habit-forming drugs in humans. Several studies have demonstrated the existence of interactions between both kind of drugs in a variety of effects and experimental models. The present study has been focused to determine whether perinatal delta9-tetrahydrocannabinol (Delta9-THC) exposure affects the(More)
We have studied the possible interaction between the cannabinoid receptor agonist CP 55,940 (1 and 50 microg/kg) and the 5-HT1A receptor antagonist WAY 100635 (1 mg/kg) in the modulation of plus-maze and holeboard activity in Wistar adult male rats. In the plus-maze, the higher dose of CP 55,940 induced an anxiogenic-like effect, whereas the lower dose(More)
Despite the increasing use of cannabis among adolescents, there is scarce information about the long-term effects of cannabinoid receptor agonists in appropriate animal models. We aimed to investigate the behavioural features of adult male and female Wistar rats that had been exposed to a chronic treatment with the cannabinoid receptor agonist CP 55,940(More)
The aim of the present work was to study the time course effects in levels of mRNA encoding N-methyl-d-aspartate receptor subunit 1 (NMDAR1) after long-term cocaine self-administration (1 mg/kg/ injection) and its extinction using a yoked-box procedure. NMDAR1 content was measured by quantitative in situ hybridization histochemistry in prefrontal cortex,(More)
We have previously shown that the acquisition rate of intravenous morphine self-administration under a fixed ratio one (FR1) schedule of reinforcement was greater in Lewis (LEW) than Fischer 344 (F344) rats. The purpose of the present experiment was to examine the relative motivational properties of morphine (1 mg/kg) or food under progressive ratio (PR)(More)
Dose-response studies are thought to be a valuable tool to predict the most genetically drug-vulnerable individuals. However, dose-response curves for morphine self-administration have not yet been examined and nor strain differences might be evident. Therefore, this study aimed to define the dose-response curve for morphine self-administration (0.25, 0.5,(More)
Lewis (LEW) and Fischer 344 (F344) rats show differential morphine self-administration rates. In this study, after animals of both strains self-administered morphine (1mg/kg) or extinguished this behaviour for 3, 7 or 15days, we measured the binding to, and functional state of mu opioid receptors (MORs) as well as proenkephalin (PENK) mRNA content in(More)
MDMA (3,4-methylenedioxymethamphetamine, "ecstasy") administration to mice produces relatively selective long-term neurotoxic damage to dopaminergic pathways. There is strong evidence indicating that the dopamine system plays a key role in the rewarding effects of ethanol and modulates ethanol intake. Using a two-bottle free-choice paradigm, we examined the(More)
Accumbal excitatory amino acid (EAA) transmission has been implicated in cocaine addiction. However, the time course effects of extinction of cocaine self-administration on EAAs are unknown. The objective of this study was to define the time course of cocaine self-administration and extinction effects on glutamate and aspartate levels in the nucleus(More)