Addicted rats have same compulsive drive for cocaine as humans do

Recent research has demonstrated that addicted rats have the same compulsive drive for cocaine as humans do. Two new studies, a French and a British one, show that rats can become addicted just like we do.


Scientists say this new research could help us develop anti addiction drug therapies for humans.


What goes on in your brain when you are experimenting with drugs is quite different from what changes take place in your brain when you become addicted, say experts. These two new studies give us insight into what goes on when the person (animal) becomes addicted.


The scientists realised the rats were addicted when the rats were willing to go through hell to get their drug.


The French study allowed the rats to have access to cocaine for three months (previous studies just went up to 30 days). If the rats placed their noses in a hole in the cage they would get a cocaine injection.


When humans are addicted they will still seek to get their drug even if the route to getting them is unpleasant. In these new studies the scientists cut of the rats' drug supply and watched how persistent they became.
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Lead researcher, Pier Vincenzo Piazza, INSERM, France, noticed that 17% of the rats still persisted, even if it meant getting electric shocks. About 15% of human cocaine takers become addicted and are willing to go through hell to get their drugs.


The British scientists, at Cambridge University, also noticed that the rats were still willing to experience electric shocks on their feet in order to get their fix of cocaine. This only happened with the rats which had been taking the cocaine for a long time. The rats that had only been taking the drug for a short while gave up after the first electric shock.


This shows that addiction is related to how long one has been taking the drug. The scientists said that there must also be a genetic factor as only 17% of the rats (and 15% of humans) become addicted over the long term.


Finding out what makes some people susceptible to addiction is the next step, say the scientists.