Thin-film electrodes developed at Lawrence Livermore National Laboratory have been used in human patients at the University of California, San Francisco (UCSF), generating never-before-seen recordings of brain activity in the hippocampus, a region responsible for memory and other cognitive functions.
Surgeons at UCSF placed the flexible arrays on the brains of a group of patients while they were already undergoing epilepsy-related surgery. They recorded electrical signals across the exposed hippocampus while some patients were under anesthesia and others were awake, and conscious patients were given visual cues and spoke words while their neural activity was recorded. This approach allowed the researchers to detect traveling waves (TWs) moving across the hippocampal surface and identify new properties about them, including how they may contribute to human cognition.
“We’ve developed an enabling technology for demonstrating a phenomenon that wasn’t really possible before,” said LLNL’s Implantable Microsystems Group Leader Razi Haque. “This challenge required creation of novel, conformable and higher-density electrodes that allows them to be more flexible and wrap around specific, deep regions of the brain. This study is validation that the approaches we’re using are getting us consistent, usable and useful data. That’s the driver for us as engineers — to be able to build the tools that scientists can use to do new science.”
