2003 / 2

The neurobiology of methamphetamine abuse

Methamphetamine synthesized in 1887, also known as "speed", "crank", "go", 'meth', or "poor man's cocaine", was used in the clinic until the 1930s. At present methamphetamine illegal production has led to widespread problems with its abuse. Methamphetamine causes dopamine, noradrenaline and serotonin release into the synapses in areas of the brain involved in reward and movement resulting in strong and long-lasting stimulant effects with rapid onset. Chronic methamphetamine intake produces: alterations in certain brain receptors and in bio-chemical mechanisms that regulate normal brain functions; neurotoxic damage to serotonergic and dopaminergic neurons; psychiatric complications such as paranoia, and hallucinations. The article reports on neurobiological and behavioral studies identifying methampheta-mine-induced neuroadaptations and relating them to behavioral changes contributing to reinforcement drug-taking behavior, craving and relapse. Finally, an information on current approaches to treatment of methamphetamine dependence including the Methamphetamine Treatment Discovery Program (MTDP) and the Methamphetamine Clinical Trials Group (MCTG) established by the US National Institute on Drug Abuse (http://www.drugabuse.gov/funding/SigMention04.html) is provided.

Drugs of abuse sensitization theory

The study presented brings a summarized view to the behavioral sensitization phenomenon frequently referred coherently with drug dependence. There are circumscribed both sensitization and tolerance which used to be often associated with drug dependence. Furthermore, terminological notes concerning to sensitization are explained and its neurobiological basis is outlined, especially pharmacodynamic changes which can underlie sensitization. Particularly, attention is focused on the changes of dopaminergic neurotransmitter system plasticity.

Opiates abuse during pregnancy induces long-term changes in developing organism

Drug abuse is a frequently discussed issue of the past years. Opium is one of the oldest drugs, from which its alkaloid morphine was isolated in the 19th century. Few years later, heroin, one of the most common drug of our age, was synthesized from morphine. Drug abuse of pregnant women is a growing problem of the past years, because they expose to the effects of the drug not only themselves, but also their fetus. Opiates easily cross the placental barrier into the fetal body and to the maternal milk and therefore, they affect both pre- and postnatal development of the child. After the cessation of the drug exposure the child has similar withdrawal symptoms as drug-abusing adults. Maternal drug abuse affects the developing system and thus, has long-term effects persisting till adulthood. Children of opiate abusing mothers are born smaller and also their postnatal growth is slower when compared to children of mothers, who do not take drugs. Prenatal exposure to opiates also induces long-term changes in behavior, learning and memory, reproduction, impairment of new environment and stress responses, and changes in the seizure susceptibility. These effects are probably due to alterations in neurotransmitter systems in the central nervous system affected by prenatal drug exposure. Not only the opioid system, but also the cholinergic and catecholaminergic systems seem to play a role in the effects of prenatal opiate exposure. Because there is no known therapy of all the adverse effects of prenatal drug exposure, it seems that prevention and overall battle against the drug abuse are the only effective ways how to resolve this problem.

The role of sensitization in drug addiction

The term behavioral sensitization refers to the intensification of the behavioral effects of a drug upon repeated administration. Sensitization is a rather complex phenomenon that involves unconditioned and conditioned components, and the relative importance of these components may be different among different drugs. The current interest in sensitization is largely due to the proposed role of sensitization mechanisms in the development and long-term maintenance of addiction. This paper will focus on some behavioral aspects of sensitization and will briefly describe the underlying neurobiological mechanisms.In behavioral pharmacology, the effect that is most commonly studied in the context of sensitization is locomotor behavior. All drugs of abuse, including psychostimulants and strong opiates, produce a certain degree of locomotor sensitization. This sensitization can persist for very long times after the treatment period. Sensitization to cocaine and amphetamine has been studied most thoroughly, but data on morphine sensitization suggest that, although there may be certain differences among drugs, essentially the same mechanisms operate during sensitization to drugs of abuse from different classes.Possibilities to pharmacologically modify the development and expression of sensitization have been explored intensively. Most interest focused on various glutamate receptor ligands, including NMDA, AMPA and mGluR antagonists. While the general picture suggests that the neural plasticity underlying sensitization can be blocked by such mistake state-dependency effects for genuine pharmacological blockade of sensitization.

Behavioural cannabinoid cross-sensitization to the effect of methamphetamine on exploratory/locomotor behaviour in mice

The present study confirmed a behavioural sensitization to methamphetamine effects on mouse exploratory/locomotor behaviour in the "open field" test, and cross-sensitization by cannabinboid agonist methanandamide. The apparatus Actitrack (Panlab, s. l., Spain) was used for behavioural activity measuring.

Regional Drug Policy Coordination and Management System Analysis

The drug policy coordination system analysis was carried out as part of the project of evaluation of drug measures and programmes implemented in the Region of Central Bohemia. The authors begin by describing and briefly analysing the status of regional drug policy coordination in the Czech Republic prior to the dismantling of districts and the creation of higher-level administrative territorial units - regions. In particular, the text focuses on a general description of the work assigned to the regional drug coordinator. The authors seek to specify certain aspects of the scope of the work and their interrelations, designing two possible models of incorporating the position of regional drug coordinator into the Regional Authority's organizational chart. The last secti on of the text explains and describes the regional drug policy coordination system at the vertical and horizontal levels, specifying the general scope of work assigned to the regional coordinator.

The Cigarette Dependence Scale - New evaluation possibility

In the frame of treatment or research, a valid measuring of dependence on cigrettes is impor-tant. Cigarete Dependence Scale with 5 questions (CDS - 5) or with 12 questions (CDS - 12) is an self-administerd questionnaire covering all main components of dependence according to DSM - IV and ICD - 10 except of tolerance.

Qualitative analysis of XTC - streetwork aspects

Client´s motivation - bio-psycho-socio-spiritual model of addiction