Brain imaging studies of the cocaine addict: Implications for reinforcement and addiction
- Brookhaven National Lab., Upton, NY (United States)
These studies document dopaminergic abnormalities in cocaine abusers. They also suggest a regulatory role of Dopamine (DA) in frontal metabolism. The correlation of striatal D{sub 2} receptor availability with metabolism was strongest for orbital frontal cortex (OFC) cingulate and prefrontal cortices. In cocaine abusers tested during early withdrawal (<1 week) the OFC was found to be hypermetabolic and metabolism in OFC and prefrontal cortices were found to be significantly associated with cocaine craving . Thus, we postulate that repeated and intermittent DA stimulation, as seen during a cocaine binge, activates the prefrontal and OFC cortices increasing the drive to compulsively self-administer cocaine. During cocaine discontinuation and protracted withdrawal and with decreased DA stimulation, these frontal cortical regions become hyponietabolic. Dopaminergic stimulation by a DA-enhancing drug and/or environmental conditioning will reactivate these frontal regions resetting the compulsion to self-administer cocaine and the inability to terminate this behavior. The pharmacokionetic studies with [11C]cocaine are consistent with behavioral and pharmacological studies in animals as well as in vitro studies which have revealed that while the mechanisms for cocaine`s reinforcing properties are complex, they partly involve the brain`s dopamine system and also highlight the importance of cocaine`s pharmacokinetic on its unique reinforcing properties.
- Research Organization:
- Brookhaven National Lab., Upton, NY (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 93949
- Report Number(s):
- BNL--61771; ON: DE95013846
- Country of Publication:
- United States
- Language:
- English
Similar Records
Addiction: Beyond dopamine reward circuitry
Methylphenidate attenuates limbic brain inhibition after cocaine-cues exposure in cocaine abusers.