New Technique Advances Understanding of How the Brain Works

    An electrical engineer and neuroscientists from the University of North Carolina (UNC)-Chapel Hill and North Carolina State University have developed a novel technology that reportedly will allow researchers to capture images of the brain almost 10 times larger than previously possible. The goal is to allow investigators to better understand the behavior of neurons in the brain.

    The study (“Wide Field-of-View, Multi-Region, Two-Photon Imaging of Neuronal Activity in the Mammalian Brain”) is published in Nature Biotechnology.

    A UNC-Chapel Hill research team made up of Jeff Stirman, Ph.D., Ikuko Smith, Ph.D., and Spencer Smith, Ph.D., wanted to be able to look at “ensemble” neuronal activity related to how mice process visual input. In other words, they wanted to look at activity in neurons across multiple areas at the same time. To do that, the researchers used a two-photon microscope, which images fluorescence. In this case, it could be used to see which neurons light up when active.

    The problem was that conventional two-photon microscopy systems could only look at approximately one square millimeter of brain tissue at a time. That made it hard to  capture neuron activity simultaneously in different areas. This is where Michael Kudenov, Ph.D., comes in. An assistant professor of electrical and computer engineering at NC State, Dr. Kudenov’s area of expertise is remote imaging. His work focuses on developing new instruments and sensors to improve the performance of technologies used in everything from biomedical imaging to agricultural research.

    After being contacted by the UNC researchers, Dr. Kudenov designed a series of new lenses for the microscope. Dr. Stirman further refined the designs and incorporated them into an overall two-photon imaging system that allowed the researchers to scan much larger areas of the brain. Instead of capturing images covering one square millimeter of the brain, they could capture images covering more than 9.5 square millimeters. This advance allows them to simultaneously scan widely separated populations of neurons.

    This work addresses “a major barrier to progress in two-photon imaging of neuronal activity: the limited field of view,” according to the researchers.