Dopamine and Addiction.
Annu Rev Psychol
; 71: 79-106, 2020 01 04.
Article
em En
| MEDLINE
| ID: mdl-31905114
ABSTRACT
Addiction is commonly identified with habitual nonmedical self-administration of drugs. It is usually defined by characteristics of intoxication or by characteristics of withdrawal symptoms. Such addictions can also be defined in terms of the brain mechanisms they activate; most addictive drugs cause elevations in extracellular levels of the neurotransmitter dopamine. Animals unable to synthesize or use dopamine lack the conditioned reflexes discussed by Pavlov or the appetitive behavior discussed by Craig; they have only unconditioned consummatory reflexes. Burst discharges (phasic firing) of dopamine-containing neurons are necessary to establish long-term memories associating predictive stimuli with rewards and punishers. Independent discharges of dopamine neurons (tonic or pacemaker firing) determine the motivation to respond to such cues. As a result of habitual intake of addictive drugs, dopamine receptors expressed in the brain are decreased, thereby reducing interest in activities not already stamped in by habitual rewards.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Recompensa
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Dopamina
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Receptores Dopaminérgicos
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Comportamento Aditivo
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Memória de Longo Prazo
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Neurônios Dopaminérgicos
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Motivação
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article