McGill University researchers have opened up a new path for cocaine addiction research by suggesting that the brain likely perceives it to be a reward.
The researchers have found that sniffing cocaine triggers high levels of dopamine secretion in a central region of the brain called the striatum.
They say that the significance of this finding lies in the fact that dopamine is known to play a critical role in the brain's response to reward and addictive drugs.
Lead researcher Dr. Marco Leyton, of the Montreal Neurological Institute (MNI), has revealed that the study involved 10 non-addicted users of cocaine, all of whom sniffed cocaine on one test day and placebo powder on another.
The participants underwent blood tests before and after taking the drug, and dopamine release in the brain was measured using PET scans.
"The ability of cocaine to activate dopamine release varies markedly from person to person. Our study suggests that this is related to how much of the drug the person consumed in the past," said Dr. Leyton.
The more cocaine someone has used in his or her lifetime, the more the brain will secrete dopamine during subsequent cocaine use.
"It's possible therefore that the intensity of the reward-circuit response is related to increased susceptibility to addiction," said Dr. Leyton.
The researchers admit that though their study has demonstrated the relationship between the intensity of dopamine secretion and the frequency of drug use, they still do not fully understand its mechanism of action.
They, however, say that the relationship between dopamine and cocaine means that this hormone could be a potential target for treatment against addiction.
A research article on the study has been published in the journal Biological Psychiatry.