Search results for "Narcotic"
showing 10 items of 106 documents
Effects of DA D1 and D2 antagonists on the sensitisation to the motor effects of morphine in mice
2002
Abstract Acute morphine administration produces hyperactivity in mice and repeated treatment induces an enhancement of this effect. In this experiment, we study the sensitisation to the hyperactivity induced by intermittent morphine administration (40 mg/kg) and the effects of dopamine (DA) antagonists on this phenomenon. Animals received three injections, separated by 48 h, and after each injection, their activity was registered between 30 and 60 min. In Experiment 1, animals were divided into two groups, which received saline and morphine (S–S–M) or only morphine (M–M–M). In Experiment 2, animals were divided into 12 groups. Half, which was designed to study the effects of DA antagonists …
Memantine blocks sensitization to the rewarding effects of morphine
2009
Knowledge regarding the specific brain changes and neural plasticity processes produced by repeated drug exposure may be used to advance the understanding of the neurobiology of addiction in order to design appropriate medications. In the present study, the influence of N-methyl-d-aspartate (NMDA) glutamatergic receptors on sensitization to the motor and rewarding effects of morphine was evaluated. The effects of pre-exposure to saline or 20 mg/kg morphine plus the NMDA receptor antagonist memantine (10 or 20 mg/kg) on motor activity and place conditioning induced by a low dose of morphine (2 mg/kg) were assessed. The dose of 2 mg/kg of morphine was ineffective in mice pre-exposed to saline…
Effect of adolescent exposure to MDMA and cocaine on acquisition and reinstatement of morphine-induce CPP
2007
It is well known that an elevated percentage of ecstasy users also consume cocaine. Recently, it has been reported that a high frequency of heroin smokers first consumed heroin under the effects of ecstasy with the hope of reducing the stimulant effects of the latter drug. The aim of the present study was to evaluate the effect of exposure to MDMA and cocaine during adolescence on morphine-induced conditioned place preference (CPP) and reinstatement in adulthood. In the first experiment, adolescent mice were exposed to six injections of MDMA and three weeks later their response to the reinforcing properties of 40 mg/kg of morphine was evaluated using the CPP paradigm. All the treatment grou…
The impact of home palliative care on symptoms in advanced cancer patients
2000
Physical symptoms, which are highly prevalent in patients with cancer, have a major impact on many aspects of quality of life, and the best possible quality of life is the principal aim of palliative care. Few studies have reported the impact of home care on pain and symptoms among cancer patients living at home. The aim of this study was to evaluate the impact of home palliative care given by an experienced team on symptoms in advanced cancer patients. A consecutive series of 373 patients who were referred to a home palliative care program in the period 1993-1995 were prospectively evaluated. Patients were enrolled for the presence of different symptoms (pain, nausea and vomiting, dry mout…
The dopamine release inhibitor CGS 10746B blocks conditioned physical signs of morphine withdrawal
2003
Environment previously paired with morphine withdrawal leads to conditioned physical signs of withdrawal, this effect being modulated by additional exposition to morphine administration. In this study, the putative role of dopamine in conditioned withdrawal signs is evaluated by administering the dopamine release inhibitor CGS 10746B prior to suffering two naloxone-induced withdrawals in a distinctive environment associated or not with morphine administration. The results show that dopamine seems to be necessary for the development of conditioned somatic signs of morphine withdrawal, as animals which received CGS 10746B do not present paw tremor or body shakes when they are placed in the en…
Reinstatement of Morphine-Induced Conditioned Place Preference in Mice by Priming Injections
2004
To construct a model of relapse of drug abuse in mice, the induction, we evaluated the extinction and reinstatement of morphine-induced place preference. In Experiment 1, we examined the effects of morphine (0, 2, 3, 5, 10, 20 and 40 mg/kg) in the conditioned place preference (CPP) paradigm. Mice showed CPP with 5, 10, 20 and 40 mg/kg. In Experiment 2, we evaluated the effects of two different extinction procedures. After conditioning with 40 mg/kg of morphine, the mice underwent daily extinction sessions of 60 or 15 min of duration. CPP was extinguished after seven and nine sessions, respectively. In Experiment 3, we tested the reinstating effects of several priming doses of morphine. Mice…
Ultrastructural alterations and environmental exposure influence the opiate concentrations in hair of drug addicts
1995
Hair samples were taken at autopsy from the head of 1 male and 1 female subject both known as drug abusers. Some of the strands were bleached by in-vitro cosmetic treatment. The bleached hair as well as the original hair samples were partly exposed to water or soil prior to further investigations and drug monitoring. The exposure times were 4 weeks or 6 months for water and 6 months for soil. The hair fibers were examined by transmission electron microscope (TEM) and by scanning electron microscope (SEM) investigations. The electron microscope studies confirmed that all experimental conditions had produced morphological alterations in the hair fibers. After exposure to water or to soil for …
One size doesn’t fit all: a thematic analysis of interviews with people who have stopped participating in Narcotics Anonymous in Norway
2020
Abstract Background For persons with substance use disorders (SUDs), 12-step groups (TSGs) are the most available and used peer-based recovery resource, worldwide. However, disengagement is common, and attrition may partly be due to practices and procedures within these groups that are unacceptable to a portion of the population with SUDs. Our overall aim was to identify problematic issues related to Narcotics Anonymous (NA) participation in Norway, to inform addiction professionals’ strategies when referring persons to addiction-related self-help groups (SHGs). Methods In this qualitative study, we interviewed ten individuals who had previously participated regularly in NA for at least 6 m…
Dose-dependent impairing effects of morphine on avoidance acquisition and performance in male mice.
1998
The effects of morphine (6.3, 12.6, and 25.2 mg/kg) on active avoidance behavior of BALB/C mice are explored in three acquisition sessions and in two subsequent performance sessions. Morphine-treated animals showed an increase in avoidance acquisition with respect to control group without differences in performance. However, a dramatical, concomitant rise in the locomotor activity of the animals (increase in the number of crossings during the intertrial intervals) prompted us to transform the data employing a formula with which a measure of actual learning was obtained. Applying this formula, we have observed that morphine administration impairs, dose-dependently, acquisition and performanc…
Memantine presents different effects from MK-801 in motivational and physical signs of morphine withdrawal
2003
Adaptive changes in neural systems due to chronic opiate exposure are related to the neural plasticity phenomenon, NMDA receptors being implicated in these processes, e.g. tolerance, dependence or withdrawal. In this work, we investigated the effect of two non-competitive NMDA antagonists, memantine and MK-801, in motivational (Conditioned Place Aversion paradigm, CPA) and physical aspects of morphine withdrawal. After the induction of morphine dependence, animals in which the CPA was studied, received memantine (5 and 10 mg/kg) or MK-801 (0.3-0.006 mg/kg) either during the acquisition (conditioning) or expression (test) phase of this procedure. Both drugs were capable of inhibiting conditi…