“We’ve developed an enabling technology for demonstrating a phenomenon that wasn’t really possible before,” says 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.”
LLNL developed the 32-channel multi-electrode arrays under the DARPA -funded SUBNETS (Systems-Based Neurotechnology for Emerging Therapies) program, which aims to improve treatments for neuropsychiatric illnesses in military service members.
The technique allows researchers to investigate travelling waves on the hippocampal surface caused by brain activity. The electrodes previously used to record brain activity were implanted below the surface of the hippocampus.
“This new perspective helped us discover that traveling waves move both up and down the hippocampus,” says researcher Jonathan Kleen, “this ‘two-way street’ contrasts with the ‘one-way street’ previous neuroscience research had shown. This is a big deal because we believe this may be a fundamental mechanism of how the hippocampus acts as a major hub of information and memory processing for many other brain regions. In other words, the direction the wave is moving across the hippocampus may be a biomarker reflecting distinct neural processes as different circuits engage and disengage.”