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76 Chapter 3 TODAY'S Research TOMORROW'S Health Care Memories Restored by Flipping a Switch? Do you wish that you could forget the time you dropped a plate of spaghetti in your lap at a restaurant, or that you could always remember the names of people you have met before? Wouldn't it be nice to be able to turn memories on and off with the flip of a switch? You could eliminate all of your bad memories and improve your good ones. Some day this may be possible. Theodore Berger, a biomedical engineer at the University of Southern California, has figured out how to manipulate brain cells in rats so that they can be activated or suppressed. The study involved an area of the brain called the hippocampus, a region crucial for memory formation. The team inserted electrical probes in the hippocampus. They then taught rats to learn which of several levers had to be pressed to receive a reward. During the learning process, the researchers recorded changes in the brain activity of the rats between two major internal divisions of the hippocampus, sub-regions known as CA3 and CA1. Through research, they learned these sub-regions interact to convert short-term memory into long-term memory. They were also able to pinpoint the pattern of nerve-cell activity involved in creating a solid memory. The scientists then used the electrical probes to stimulate the nerves in the same pattern and found that the rats' performance improved and the rats could remember the Additional Sources of Information • American Academy of Forensic Sciences 410 North 21st Street Colorado Springs, CO 80904 Internet address: www.aafs.org • American Institute of Biological Sciences 1444 I Street NW, Suite 200 Washington, DC 20005 Internet address: www.aibs.org • American Society for Biochemistry and Molecular Biology (ASBMB) 11200 Rockville Pike, Suite 302 Rockville, MD 20852-3110 Internet address: www.asbmb.org • American Society for Clinical Pathology 33 West Monroe Street, Suite 1600 Chicago, IL 60603 Internet address: www.ascp.org • Biotechnology Industry Organization 1201 Maryland Avenue SW, Suite 900 correct lever for a longer period of time. In order to evaluate if memory could be suppressed, the researchers gave the rats a drug that blocked the nerve-cell activity and caused the rats to forget the task. A prosthetics (artificial devices) team then created an artificial system that duplicated the pattern of interaction between CA3 and CA4 in the hippocampus. When this system was inserted into the animals, and the brain cells were stimulated with the correct pattern, long-term memory returned. A final discovery was that when the prosthetic hippocampus with its electrodes was implanted in animals with normal function, the device strengthened the memory being created. Additional research is now being conducted with primates and more advanced tasks. If research is successful, it might be possible to create a prosthetic that can be implanted in humans. This could help victims of Alzheimer's disease, stroke, or brain injury recover memory that has been lost and could improve mental function. In addition, if the prosthetic can be used to suppress memories, the device might be a method for treating individuals with post-traumatic stress disorder or other psychiatric conditions such as fears caused by a previous memory. Even though this research will require many more years of study due to the complex nature of memory in humans, if it is successful it will be a major breakthrough for many individuals. Washington, DC 20024 Internet address: www.bio.org • Biotechnology Institute 1201 Maryland Avenue SW, Suite 900 Washington, DC 20024 Internet address: www.biotechinstitute.org • Federation of American Societies for Experimental Biology 9650 Rockville Pike Bethesda, MD 20814 Internet address: www.faseb.org • Pharmaceutical Research and Manufacturers of America 950 F Street NW, Suite 300 Washington, DC 20004 Internet address: www.phrma.org STUDENT: Go to the workbook and complete the a ssignment sheet for Chapter 3, Careers in Health Care.