A Lego box to study drug addiction

WASHINGTON – Students can build many things out of Lego blocks, from models of pirate ships to programmable robots that walk and talk. Andy Gallup, now 18, has taken Legos beyond the world of toys. He used the plastic blocks to build a scientific instrument: a box with lights and levers that can hold a mouse.

Andy, a graduate of Mount Desert Island High School in Bar Harbor, Maine, built the box in the summer of 2013 while doing research at the local Jackson Laboratory. He hopes to use it to teach high school students about drug addiction. He has already used the chamber to compare how two different kinds of mice behave. Andy’s mentor, Elissa Chesler, a scientist at the Jackson Lab, described Andy’s design on November 15, here, at the Society for Neuroscience meeting.

“Addiction education is something that is currently not as effective as it should be,” Andy says. “Drug abuse is something that plagues a large portion of adolescents. It is a problem that we need to address in a new way.” Instead of basing drug-abuse education on the idea of “Just say no,” Andy is hopeful that his inexpensive plastic behavioral box will help students get hands-on education about addictive behaviors. All they need are some Legos.

Addiction is a mental illness. Its primary symptom is a behavior that is out of control. People who are addicted to substances such as alcohol spend their lives focused on the next drink. They crave alcohol and drink to excess — often. They continue to drink even if they get kicked out of school, lose a job or suffer other terrible consequences. 

To study addiction, scientists often turn to animals such as rats and mice. These rodents like drugs and sweet foods just as many people do. Scientists frequently study addictive behavior in animals in a special box called an operant chamber. Sometimes it’s called a “Skinner box,” after its inventor, B.F. Skinner. The metal box contains lights, speakers and levers. Scientists turn on the box’s lights or projects sounds in it as cues that will eventually train animals.

Chesler wanted to find a way to bring operant chambers into high-school classrooms to teach students about drug addiction. “We teach kids in school about the effects of drugs. But a lot of it is prevention,” she explains. “They don’t learn when drug use turns into abuse and addiction.” She thought an operant chamber might do a better job of teaching teens how addictions form.

The problem: Most of these chambers are quite expensive. And students might not learn a lot from just looking at the box.  Then Chesler learned about Lego Mindstorms, toy sets that bring together plastic bricks, computer programming and robotics. “The first thought that came to me,” she says, was: “we should obviously build a Skinner box out of Legos.”

Chesler was then looking for summer students for a research program at Jackson. As she interviewed Andy, she said she had a project for him — and it involved Legos. “He got very excited.”

Indeed, he did. “What’s better than a summer full of research and Legos?” Andy asks.

So instead of putting this student to work helping out in the lab, Chesler asked Andy to build an operant chamber with a Lego set. Over the summer, the teen learned a lot about what these chambers are used for and the computer software needed to run them. In the end he had a small working chamber, with a lever and a little catapult. That catapult made sure the mouse got one pellet each time it pressed the lever.

Over the next year, other lab members helped to improve the plastic box until it looked just like a metal operant chamber, with two lights and two levers. While operant chambers are expensive to buy, the Lego model cost a comparatively cheap $600.

That was more than a year ago.

In a second summer, Andy carefully documented every step of the process. When Andy and Chesler release the directions, they hope that high school students everywhere will be able to build their own operant chambers. “The Legos are widely available and many schools already have them,” explains Chesler. “So they can build the device themselves.”

How do you use such a behavior chamber? Start by placing a mouse inside it and allow the rodent to get used to this new environment for about an hour. Perhaps an hour later, turn on a light and play a tone as a lever slides out beneath the light. At first, a rodent won’t know what to make of this. But in wandering around, the mouse may bump into the lever by accident or simply out reach for it out of curiosity. Hitting the lever sends a food pellet into a little bin for the mouse to eat. After a few days of this training, the mouse learns that light means lever and lever means food. This is called reinforcement learning.

With all the instructions that Andy has worked on, building the chamber may be the easiest part. It may be a lot harder to get a mouse to put in it. There are many rules and regulations that control how scientists keep research animals. The goal of those rules is to make sure research animals are kept comfortable and healthy. A high school usually cannot ensure these conditions.

But Chesler is hopeful that high schools might be able to build the boxes, and then collaborate with local colleges and universities. Teens might be able to bring their boxes to a college lab and learn how they work using lab animals.

She hopes to publish the design and details for its use in a paper, so that high school teachers anywhere can bring the operant chamber to their students. 

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Power Words

addiction  The uncontrolled use of a habit-forming drug or uncontrolled and unhealthy habit (such as video game playing or phone texting). It results from an illness triggered by brain changes that occur after using some drugs or engaging in some extremely pleasurable activities. People with an addiction will feel a compelling need to use a drug (which can be alcohol, the nicotine in tobacco, a prescription drug or an illegal chemical such as cocaine or heroin), even when the user knows that doing so risks severe health or legal consequences. (For instance, even though 35 million Americans try to quit smoking each year, fewer than 15 out of 100 succeed. Most begin smoking again within a week, according to the National Institute on Drug Abuse.)

animal model    A nonhuman animal used to stand in for people in research testing. Which animal a lab uses will depend on how closely parts of its body or chemical-signaling systems match those in people.

behavior  The way a person or other organism acts towards others, or conducts itself.

neuroscience  Science that deals with the structure or function of the brain and other parts of the nervous system. Researchers in this field are known as neuroscientists.

operant chamber  A metal or plastic box that scientists use to study animal behavior. The box is equipped with levers, lights and sounds. Rats, mice, birds and monkeys learn that a light is connected with a lever, and that pressing the lever leads to a desired reward. The chambers are used to study many aspects of how animals behave — often as a clue to human behavior.

reinforcement  Some consequence that guides the future behavior of an animal or person. If a rat presses a lever and receives a food pellet, that food pellet becomes a reinforcement of lever-pushing — it’s the reward that will teach the rat to press the lever again.

reinforcement learning  In which an animal or a person learns to perform a specific task to achieve a desired reward.

reward  (In animal behavior) A stimulus, such as a tasty food pellet, that is offered to an animal or person to get them to change their behavior or learn a task.