Researchers at the University of Michigan are using tiny probes with electrodes and the world’s smallest implantable LEDs to understand how the brain’s neurons communicate with each other. This work could lead to breakthroughs in understanding and treating neurological diseases such as Alzheimer’s. The researchers are using their background in electrical engineering to study the circuitry of the human brain. Project leader Euisik Yoon explains, “Using micro-LED probes, we may tease out how the signals propagate inside the neural circuitry so that we can understand how memories are formed, retrieved and replaced.”
The project is part of a field called optogenetics, which involves scientists using light to control cells that have been genetically modified to be sensitive to light. Now, the Michigan team has built probes with LEDs that are so small that they be used to turn neurons on and off. While this is happening, tiny electrodes measure the activity so that the researchers can see how a change in a single neuron’s behavior affects the surrounding network. By controlling one neuron’s behavior and then observing how its neighbors react to the change, the researchers are able to get an unprecedented understanding of how the billions of neurons in the human brain communicate with each other.
“Hundreds of millions of people suffer from neurological diseases, but treatment methods and drugs are currently very limited because scientific understanding of the brain is lacking,” said Fan Wu, a postdoctoral researcher in electrical engineering and computer sciences and co-first author on a new paper on the findings. “We have developed a tool that is needed to better understand how the brain works—and why it doesn’t work—to try to solve to these problems.”
The researchers successfully tested their tiny electrodes and LEDs by implanting them in mice. The results are described in a paper that is featured on the cover of the latest issue of the scientific journal Neuron.