In their first study in animals, the researchers injected billions of their viral concoction into laboratory mice, and found a strong immune response was generated against the vaccine. Also, when the scientists extracted the antibodies produced by the mice and put them in test tubes, it gobbled up cocaine. They also saw that mice that received both the vaccine and cocaine were much less hyperactive than untreated mice given cocaine.
Booster Shots to Dampen the Cocaine High
In this study, the researchers sought to precisely define how effective the anti-cocaine vaccine is in non-human primates, who are closer in biology to humans than mice.
They developed a tool to measure how much cocaine attached to the dopamine transporter, which picks up dopamine in the synapse between neurons and brings it out to be recycled. If cocaine is in the brain, it binds on to the transporter, effectively blocking the transporter from ferrying dopamine out of the synapse, keeping the neurotransmitter active to produce a drug high.
In the study, the researchers attached a short-lived isotope tracer to the dopamine transporter. The activity of the tracer could be seen using positron emission tomography (PET). The tool measured how much of the tracer attached to the dopamine receptor in the presence or absence of cocaine.
The PET studies showed no difference in the binding of the tracer to the dopamine transporter in vaccinated compared to unvaccinated animals if these two groups were not given cocaine. But when cocaine was given to the primates, there was a significant drop in activity of the tracer in non-vaccinated animals. That meant that without the vaccine, cocaine displaced the tracer in binding to the dopamine receptor.
Previous research had shown in humans that at least 47 percen
|Contact: John Rodgers|
Weill Cornell Medical College