cocain+lab+description

In this lab students are introduced to the role that neurotransmitters play in the brain, with special emphasis on dopamine. It has been well know for some time that when cocaine reaches the relevant centers in the brain it is accompanied by a large spike of dopamine. What was not known until recent studies, is the role that dopamine plays in the cocaine-seeking phase, before the drug is taken into the brain. In this virtual laboratory, students become neurobiologists and conduct a study on the effects of cocaine on the behavior of rats. In particular, they gather data on the correlation between dopamine levels and rat behavior. Students begin the task by acquainting themselves with the lab and then (at the virtual desk) learn about brain structure and neurotransmitters. The first activity is to weigh the rat, measure the right amount of anesthesia, and inject the rat – preparing it for surgery. Next the student observes the surgical procedures that implant electrodes and sensors in the rat's skull. This recording equipment permits the monitoring of dopamine levels in the rat's brain while the rat’s behavior is observed. With careful observation students will recognize that there is a dopamine spike right before the rat pushes the lever that self-administers the cocaine. This confirms the hypothesis that dopamine is involved in cocaine-seeking, not merely in cocaine consumption. And when a light and tone appear, that have been associated with the presence of the drug, the cocaine-seeking dopamine spike occurs even when no cocaine is received. There is reason to believe that this may give crucial insight into our understanding of addiction, even in humans. For example, recovering addicts may receive a dopamine spike simply by being around old friends and old environments associated with past cocaine-seeking activities, even if they never actually take the drug. This particular study was picked for several reasons. First, students learn about brain physiology and the biochemistry of neurotransmitters in a fun, engaging environment. Second, it doesn’t merely convey “facts” about which there is a settled consensus, but it takes the student into an exciting controversy. For years it was believed that dopamine functioned as a simple “reward.” It does do that, but the situation is much more complicated than that. There is further data that this lab prepares students to understand that will show some very surprising properties of dopamine that many researchers are still having difficulty accounting for. By bringing students into the middle of this drama, they learn something of the excitement involved in doing breakthrough research. Third, the research methods used are “state-of-the-art.” In fact, they are more than state-of-the-art. The design involves two cutting edge elements. It is only recently that a special type of chemical microsensor technique called //fast-scan cyclic voltammetry// was developed that can measure dopamine 10 times per second, which is faster than the animal bar presses in intracranial selfstimulation. At the moment, that technique requires long cables stretching from implants in the rat’s skull to the computers and the source of cocaine (see Fig. 1 below). But Dr. Paul Garris, who is consultant on this project and whose work is featured in our labs, is part of a team that is developing a patented system to reduce all of the equipment to tiny transistors and processors (Fig. 2 below) that can fit in a pack on the rat’s back – like the one featured in this lab (Fig. 3 below). So while this technology is technically “science fiction” this system is projected to be in use in 12-24 months. In fact, within that time span it may even be approved for use with humans (Fig. 4). Getting ahead of the medical / technological curve is part of the spirit of The Mind Project approach to K-12 curriculum. This module has a creative ending. Instead of leaving the student only with what the student is capable of remembering, the program produces a journal article; not a previously published article, but a //Virtual Publication// that includes all of the descriptions, experimental designs, observations, hypotheses, data collection, and final conclusions arrived at by the student in the course of conducting the experiment. When the student leaves, she will have a record of what she has done, packaged in the form of a publication with her own name on it that will, we hope, be the first of many that she will produce as she pursues a career in medical research.
 * Lab overview