Drug addiction at the atomic level: Chem prof talks dopamine studies

Home Science & Tech Drug addiction at the atomic level: Chem prof talks dopamine studies
Drug addiction at the atomic level: Chem prof talks dopamine studies

Assistant Professor of Chemistry Kelli Kazmier presented her research on drug addiction at the atomic level last Thursday as a part of Mossey Library’s “Our Faculty’s Ongoing Research” lecture series. 

Kazmier spoke on her findings pertaining to drug addiction and its effect on the human body. Specifically, the way drugs impact dopamine levels in the brain. 

“One of the interesting features of drug addiction is that it seems to modify this dopamine pathway,” she said. “We have pre-existing evidence that suggests that when you mess with the dopamine pathway—when you mess with the levels of dopamine in the brain—you have a wide range of effects.”

Effects like euphoria and motor control loss are common. With drugs increasing dopamine levels, the body is artificially rewarding itself—which impacts the learning center of the brain. “You’re basically teaching the brain that drugs are good,” she said.

The end goal in her research is to help create a substance that imitates the impact of drugs, with no negative side effects.

“The goal in the long term would be to try to identify how it’s working so that we could modify it in a way that would help us treat addiction,” she said. “Like a stimulant that wouldn’t have any addictive side effects.”

Kazmier specifically studies the dopamine transporter: the protein that removes dopamine after release. The dopamine transporter is specifically targeted by cocaine and amphetamines. 

“The way we get dopamine into the synapse, the way we get elevated dopamine in the brain is by blocking the protein that removes it,” she said. “That’s how cocaine works: blocking the protein that takes [dopamine] back up into the cells and removes it from the intercellular spaces.”

The dopamine transporter is difficult to study in a lab, however, so Kazmier and her team of students turn to a similar protein: the leucine transporter. 

 “The leucine transporter is a protein, it’s in the same family. It’s related. It does a similar job, but it comes with less of the baggage,” she said. “It doesn’t have the same negative structural features that make it impossible to study in the lab.”

Leucine is easy to study in the lab but it has a clear difference: leucine does not transport chloride while dopamine transporters do. But some evidence suggests it was possible to change this and make leucine carry chloride, too, which would make testing leucine far more useful in understanding dopamine. 

“There’s this literature out there that suggests that if you make a single point mutation to leucine, you can convert it to transport chloride as well—to make it more like the dopamine transporter,” she said. 

So Kazmier and her students tested it in their Dow Science lab. 

“We unexpectedly found that making the mutation does not do what we thought it would do,” she said. 

Leucine reacted differently than expected and Kazmier has years of research ahead of her to figure out why.  

“Anytime you get a result that completely defies your expectations, you’re off to the races,” she said. “It’s a brand new part. We have to track down every lead, we have to figure all this out. This is gonna be a major project in my lab for a while.”

She predicts it may take her entire career to figure out the leucine and dopamine transporter relationship. Kamzier spoke at length about these experiments to a crowd of over 50 students.

Constructing the talk was “a bit of a challenge,” Kazmier said, as she had to condense slides from 12 lectures for the presentation. 

“I taught an entire course on this material and I condensed it into a 40-minute chat,” she said. 

Not only has Kazmier taught a course on this topic, but she has been studying it for over 13 years.

“I’ve always had this interest in drug addiction. Like many of us, I have addiction in my family,” she said.

One summer in college, Kazmier pursued this interest by reading hundreds of pages on the science of drug addiction. 

“When I was doing my summer internships, I would go to the library and check out every book on a topic,” she said. “One summer I decided I would learn everything there is to know on drugs and abuse.”

When it came time for her graduate work, she knew she wanted to research this topic, but not “explicitly addiction.” Instead, she studied the proteins surrounding addiction. 

“I liked the idea of studying proteins that had relations to mental health and addiction,” she said.

Since coming to Hillsdale in 2016, she has worked with students over the summer to conduct experiments.

Many students who know Kazmier attended the lecture.

Junior Sonya Wirkus has taken two classes with the chemistry professor and said “her enthusiasm in her study is contagious.”

“It’s encouraging to have professors like Dr. Kazmier that push us to study the world just because it’s exciting, interesting, and beautiful,” Wirkus said. “I’m glad that more students had the opportunity to observe some of that joy and learn a little more about the biochemistry of the brain last Thursday.”

Junior Katie Ingham agreed, calling the lecture “a great example of her ability to example how the minute details of science affect the big picture of what humans experience.”