Some questions from the audience answered by Dr. Han:

Q: Is the effect of "feeling high" that a person gets from exercise like jogging different from the "feeling high" effect of taking drugs?

A: Yes and no. That jogging activates the reward pathway in the brain is similar to how addictive drugs activate the very same reward pathway; however, their "intensities" are different in that jogging is much milder stimulator compared to cocaine or other psychostimulants. This is somewhat similar to getting one dollar vs. 10 dollars for a tip. Nonetheless, jogging can be also addictive, which is a good behavioral adaptation!

Q: What are the effects of legal tranquilizers (benzodiazepines like Xanax and Valium) on the dopamine in the reward system?

A: Benzodiazepines do not directly act on dopamine or the reward system, but indirectly affect them. The primary target of benzodiazepines is the inhibitory neural system involving GABA (in a way, they are similar to alcohol, but alcohol acts on many targets) and thus they help relieve anxiety. Similar to alcohol, they induce changes in the brain, causing tolerance and dependence (especially after long-term use). Moreover, they can be addictive (depending on how long or often one uses them) because they indirectly affect the reward system. However, their addictive potency is lower than that of cocaine or heroine.

Q: Are you aware of any detrimental effects to the brain from being addicted to the caffeine in coffee or sodas?

A: To my knowledge, they do not have any detrimental effects on the brain. Interestingly, caffeine can be somewhat beneficial for certain cases --- there is an inverse relationship between heavy coffee drinking and susceptibility to Parkinson's disease (well, I am a heavy coffee drinker, so I have to find something good about it…).

Q: Do we know from brain scans of long-recovered addicts if a brain can ever completely recover from drug addiction?

A: I am not aware of any studies that have investigated the brain activities or scans of the long-term drug abstinent people (abstinent many years) with full recovery. This is largely due to the fact that a high percentage of the abstinent people relapse (thus, hard to find proper subjects for the study). Also, the brain imaging is a relatively new technology, so there have not been enough time for long-term follow-up studies. I believe such studies are currently underway and we will learn more about it in near (hopefully) future!

Q: Does glucose metabolism play a role in addiction?

A: Not to my knowledge. Glucose metabolism is routinely used to monitor brain activities since the brain uses glucose as an energy source. When a certain part of the brain is actively working, there tends to be higher energy demand and thus higher glucose influx in that area. Upon drug abuse or addiction, many parts of the brain are not as active as they should be due to detrimental effects of drugs and/or neural adaptations, which is easily visualized by glucose metabolism or blood flow. Thus, glucose metabolism is used to monitor brain activities and is not a cause of addiction per se.

Q: Is there a difference in addiction vulnerability between males and females?

A: Excellent Question! This is one of the quintessential questions in the field as it affects prevention as well as treatment strategies. The short answer is yes, but not always so. Men and women are different biologically, behaviorally and socially, which lead to a complex pattern of gender differences in different aspects of drug use, effects, vulnerability, abuse, addiction and treatment. For example, men have more opportunities to use drugs. But given the same opportunities, both genders equally likely use drugs and with certain drugs (cocaine, heroine, inhalant, and nicotine) similar proportions likely progress to become addicted. On the other hand, women tend to be more addicted to sedatives or similar kinds and men are more likely abusing and addicted to alcohol and marijuana. Biologically, women and men show different physiological responses (e.g. cardiovascular responses, etc.) and brain activities upon injection or exposure to different drugs, drug-associated cues and the drugs used for abuse/addiction treatment, leading to different courses of addictive processes and recovery. This is an active area of research and we are learning much more on this topic as exciting findings are continuously being reported.

 

"Addiction: A Bad Case of Good Memory" Is Topic of Saturday Science Lecture on 3 February

29 January 2007 —A free public lecture titled "Addiction: A Bad Case of Good Memory," will be given on Saturday, 3 February 2007, by Kyung-An Han, associate professor of biology at Penn State. The lecture will take place from 11:00 a.m. to about 12:30 p.m. in 100 Thomas Building on the Penn State University Park Campus. The event is the second of five weekly lectures in the 2007 Penn State Lectures on the Frontiers of Science, an annual series designed as a free minicourse for the enjoyment and education of residents in Central Pennsylvania communities. The theme of the series this year is "Broken Brains: New Research on Brain Disease Is Revealing How the Healthy Mind Works."

Han will discuss how commonly abused drugs including alcohol, cocaine, marijuana, and opiates act in the brain and how their recurring intake causes adaptive changes in brain functions, ultimately leading to the disease states of dependence and addiction. She also will discuss vulnerability factors such as genetic components, age, and the environment. Her lecture will include new research involving animal models and human subjects, which together are helping to unravel the neurobiology of addiction and to provide insights into sensible preventions and treatments.

The primary focus of Han's research is to understand the molecular and cellular basis of learning and memory as well as drug addiction-a form of involuntary learning and memory. "The capacity to learn and remember distinct environmental cues, or one's actions associated with harm or food reward, is fundamental for survival in all animals," she explains. To unravel how different types of learning and memories are acquired and stored in the brain, Han uses the fruit fly as an animal model as well as various behavioral paradigms. Her studies identify the crucial roles of distinct monoamine chemical systems in a learner's response to punishments or rewards, to active or passive learning, and in making distinct adaptations to the chronic use of alcohol and cocaine. Her research is supported by the National Institutes of Health and the National Science Foundation. She teaches a course titled "Molecular Basis of Neurological Diseases" at Penn State.

Han received a bachelor's degree in biochemistry from the Yonsei University in Korea, and a doctoral degree in biochemistry from Roswell Park Cancer Institute in New York. She was a postdoctoral fellow at the Cold Springs Harbor Laboratory and Baylor College of Medicine and was a member the research faculty there from 1996 to 1999. She came to Penn State in 1999 as an assistant professor of biobehavioral health and joined the Department of Biology in 2004. In 2006, she was promoted to associate professor of biology. She has filed two patent applications based on her research.

Han is a member of the Society of Neuroscience and the American Association for the Advancement of Science. She is an ad hoc reviewer for Genetics, the Journal of Neurobiology, Comparative Biochemistry and Physiology, Journal of Comparative Physiology A, and Insect Biochemistry and Molecular Biology.

The 2007 Penn State Lectures on the Frontiers of Science are a free minicourse consisting of five consecutive lectures focused on recent research on the structure and function of the human brain. Audience members who attend the consecutive lectures will gain an understanding of how the study of brain disease is helping researchers to make new discoveries about normal brain function. The lecture series is sponsored by the Penn State Eberly College of Science, with additional financial support provided by Pfizer Inc. The remaining lectures include:

• "Serotonin and the Misbehaving Brain: Unraveling the Biology of Anxiety and Depression" by Anne Andrews, assistant professor of molecular toxicology at Penn State, in 100 Thomas Building on 10 February;
• "Schizophrenia: The Broken Brain and How to Fix It" by Robert Levenson, professor of pharmacology at Penn State, in 100 Thomas Building on 17 Febrary; and
• "Brain Repair: Hopes and Challenges" by Gong Chen, assistant professor of biology at Penn State, in 112 Kern Building on 24 February.

Thomas Building is located at the intersection of Pollock and Shortlidge Roads on the Penn State University Park Campus. Free parking is available in the Eisenhower Parking Deck behind Eisenhower Auditorium. Kern Building is located at the corner of Curtin and Burrowes Roads. Parking is available free of charge at the Nittany Parking Deck adjacent to the Nittany Lion Inn on Fischer Road.

For more information or access assistance, contact the Eberly College of Science Office of Public Information by telephone at (814) 863-0901, by e-mail at science@psu.edu, or click on the web link at http://www.science.psu.edu/alert/frontiers/

 

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