Getting to the core of addiction: Hatching the addiction egg

Addiction to drugs of abuse, such as cocaine, remains a clinical and social problem, in part owing to the lack of effective treatment. The challenges of coping with addiction extend to the bench, pulling researchers to continue exploring the origins of addiction and the molecular and structural changes in the brain driving lack of self-control and impulsivity in people suffering from addiction or relapses. But what triggers these brain alterations has not been fully elucidated, and addiction animal models showing disparate outcomes have puzzled researchers. An assumed paradigm poses that brain changes during addiction result from chronic drug use. In 'Bedside to Bench,' Peter W. Kalivas and Kathleen Brady examine a clinical study that counters this model, suggesting that pathological brain alterations involved in cocaine addiction may also be inherited, contributing to addiction vulnerability. The implications for future preclinical studies and clinical care are numerous. But the controversy surrounding addiction also reaches the molecular level. In 'Bench to Bedside,' Marisela Morales and Antonello Bonci peruse a study in mice showing that activation of brain cannabinoid receptor 2—thought to have no effect on addiction owing to its scarcity in the brain—attenuates effects of cocaine use, including rewarding and locomotor stimulation. This may open the door to the development of selective drugs to treat cocaine addiction.