[Mechanisms behind drug dependence].
The neurobiological mechanisms involved in the development and maintenance of drug dependency are reviewed and discussed. Whereas physical dependency is related to abstinence symptoms with a noradrenergic hyperactivity in locus ceruleus, motivational dependency is related to euphoria, which correlates with dopaminergic activity in the mesolimbic pathway, especially in nucleus accumbens. Despite the fact that many addictive drugs are chemically unrelated, they increase the extracellular levels of dopamine in nucleus accumbens. This has been observed with cocaine, amphetamine, ecstacy, nicotine, opiates, ethanol, and cannabinoids. On the other hand, substances like LSD do not appear to influence the dopamine level in the mesolimbic pathway. Increasing knowledge about how drug abuse modulates signal pathways in discrete parts of the brain gives a new insight into the development and maintenance of drug dependency.
Strugstad
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Farmakologisk avdeling, Det medisinske fakultet, Universitetet i Tromsø.
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D002186:Cannabinoids / Q000009:adverse effects / Q000378:metabolism / Q000494:pharmacology; D003214:Conditioning, Classical; D005059:Euphoria; D006213:Hallucinogens / Q000009:adverse effects / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D009294:Narcotics / Q000009:adverse effects / Q000378:metabolism / Q000494:pharmacology; D011954:Receptors, Dopamine / Q000235:genetics / Q000378:metabolism; D011957:Receptors, Opioid / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D019966:Substance-Related Disorders / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology / Q000523:psychology
D002186:Cannabinoids; D006213:Hallucinogens; D009294:Narcotics; D011954:Receptors, Dopamine; D011957:Receptors, Opioid
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