Researcher tests drug to quell addiction
October 19, 2009 by VIVIAN GIANG
Filed under News
Researchers in the University’s College of Veterinary Medicine are using a drug commonly associated with treatment for schizophrenia to help drug addicts during the withdrawal process.
The researchers tested D-Serine, an amino acid, for its effectiveness in learning capabilities for cocaine addicts.
When John Wagner, professor of physiology and pharmacology, initiated the research project, his interest was to find a class of drugs that might facilitate learning and memory in a target in the brain, known as the NMDA (N-methyl-d-aspartate) receptor.
This particular nerve cell receptor is critically important in memory and learning capabilities.
“Our interest in using it and applying [D-Serine] to the field of drug addiction was to consider the field of drug addiction treatment – cocaine and amphetamines in particular,” Wagner said.
“One of the only available therapies currently for treating those addictions is behavioral types of therapies, such as counseling.”
“When a person is engaged in treatment sessions, if you can enhance the effectiveness of the behavioral therapy, then you would presumably enhance the effectiveness of the treatment and the cravings of the relapse in the state of addiction,” he said.
D-Serine is a natural substance found in the brain and is potentially one of the classes of drugs that are known as cognitive enhancers. As opposed to a synthetic substance, D-Serine would not be something new being introduced into the nervous system.
“D-Serine itself is not an addictive drug – we’re not replacing cocaine with another stimulate drug – and it is not an anti-craving medication” Wagner said. “It is a drug that would be given along with behavioral therapy to enhance the effectiveness of counseling or other cognitive behavioral types of therapy.”
At the time of the research, Lakshmi Kelamangalath was a graduate student at the University and worked alongside Wagner and then-postdoctoral student Claire Seymour.
During the first 15 days of the assignment, the purpose was to self-administer cocaine in 90-minute sessions to male Sprague Dawley rats.
“To make the rats addicted to the cocaine, we put them in a cocaine setting – there are two levels – and in the top part of the box, the cocaine comes through the tubing,” said Kelamangalath, now a post-doctoral fellow at Creighton University in Omaha, N.E. “When the rats pass through the ‘active level,’ they get a cocaine infusion on to the top of their skulls and they learn that one level gets them cocaine and the other does not.”
On the sixteenth day, a period known as the “extinction session,” the rats went back to their cages and their level of active cocaine was measured. For the next five days, the amino acid D-Serine was administered and the rats do not receive any cocaine.
Kelamangalath said the second portion of the research is the most important since most researchers are only interested in the addiction part, but do not look into the next step.
After the five days known as the “re-enactment” portion, the rats were then given a single dose of cocaine to see how they processed the “extinction session” – if they became addicted or “extinguished properly.
“I thought addressing this was an important economical problem . it’s one of the most important issues that we are facing,” Kelamangalath said. “It’s just a basic finding, but if we can enhance the learning process, then there can be a lot of changes in the future”
Wagner said he hopes to further this particular research, if funding becomes available.
“One of the interesting things to test is an opiate, such as heroin, to see how D-Serine affects other drugs and to look at the course of time – how long D-Serine and behavioral therapy affects a person,” Wagner said. “Even if D-Serine itself isn’t the agent that ends up being utilized in the treatment of drug addicts, it provides a strong example of motivation for other agents to look into other drugs that might be working in similar ways.”
