Traumatic injuries, diseases and various events such as a stroke can leave a person with serious memory impairment. Although rehabilitation and treatment therapies often help restore some or all functionality, the process is time-consuming, labor-intensive and expensive.
That is why researchers at the University of Southern California Viterbi School of Engineering and Wake Forest University Department of Physiology and Pharmacology are exploring a new option: a brain implant that mimics the human hippocampus and helps restore memory function. A prosthetic device—scientists have already tested the concept successfully on rats—could revolutionize treatment for humans, notes Theodore Berger, Ph.D., a professor of Biomedical Engineering at USC and director of the Center for Neuroengineering.
A multidisciplinary team has focused on this project for more than a decade. Recently, in conjunction with Sam A. Deadwyler, Ph.D., of the Wake Forest Department of Physiology and Pharmacology, they achieved a major technical breakthrough. Researchers learned how to switch memories on and off in rats through the use of embedded electrical probes. The team recorded changes in the rats’ brain activity between the two major internal divisions of the hippocampus, known as sub-regions CA3 and CA1.
“Flip the switch on, and the rats remember. Flip it off, and the rats forget,” Dr. Berger explains. In the experiment, the researchers had rats learn a task, pressing one lever rather than another to receive a reward. Then, when the researchers used drugs to block the normal neural interactions between the two brain regions, the previously trained rats couldn’t achieve the task. Later, with the introduction of a prosthetic device, long-term memory returned.
The next step, Dr. Berger says, is to develop a prosthetic hippocampus for primates. If the technology displays the same ability to restore lost memory function in monkeys, researchers would then develop the technology for humans. The key is to see if the same relationships exist for hippocampal processing in more advanced animals with more complex brains, Dr. Deadwyler explains. An implantable hippocampus device in humans would likely be more than a decade away.
CONNECT THE DOTS
For a more detailed look at Dr. Berger and Dr. Deadwyler’s research into the development of a hippocampal prosthesis, visit the Journal of Neural Engineering. Another consortium of scientists based in the UK is also conducting research into restoring memory function through the use of prosthetic microchips. Visit the ReNaChip project to learn more. Get more information about recognizing the signs of stroke.
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