Researchers at the University of California, Davis created miniaturized microscopes for real-time, high-resolution, non-invasive imaging of mouse brain activity. This device is a key step in revolutionizing how neuroscientists study the brain.
“What we do is to open a behavioral paradigm by creating techniques to image brain activity with free-moving and operating mice,” says Weijian Yang, professor of electrical and computer engineering. “The goal is to create devices that can real-time research into mouse brain activity and behavior. To see how brain activity drives behavior and perception.”
This microscope advances insight into how the brain functions. This is expected to benefit human health by strengthening the development of new, improved treatment strategies for brain damage.
The first similar imaging system known as Deepinminiscope is described in a paper published in Science Advances.
Repetitive design
Deepinminiscope creates a lensless camera that can generate three-dimensional images from a single exposure, based on Yang's previous work.
This imaging system was suitable for large objects in an environment with minimal light scattering, such as robotic vision of part assemblies, but it was difficult to capture details of biological or biomedical samples. Light scattering is common in living tissues, and signal contrast tends to be low, and reconstructing complex features in large quantities of space is a computational problem.
Deepinminiscope solves these problems with a new mask design that includes over 100 small, high-resolution lenslets. The new neural network reconstructs the 3D image by combining images from each lenslet.
Deep (learning) insight
Deepinminiscope's neural network combines various approaches to machine learning to create deployed neural networks. This allows for instant, accurate, high-resolution reconstruction of fine details across large 3D volumes. Using this tool, Yang and his research team recorded neuronal activity in mouse in real time.
“Our algorithms combine interpretability, efficiency, scalability and accuracy,” says Feng Tian, a postdoctoral researcher in Yang's lab and the first author of the corresponding paper. “It requires only minimal training data, but it can handle large datasets with high speed and robustness and accuracy.”
hat trick
By being small and ergonomically small enough to wear the mouse comfortably and safely as it moves freely, Yang aims to allow neuroscientists to study behavior in real time.
With just 3 square centimeters, grape size and 4 pennies weighing 10 grams, Deepinminiscope is nearby.
Previously, if similar designs were constrained by the large footprint of traditional cameras, Deepinminiscope uses the sensor as a compact, bare circuit board with image sensors rather than as a self-contained, enclosed system.
Yang's ultimate goal is a 2-square centimeter device, which compares the size of a mouse hat. Furthermore, in the next iteration, Yang wants to make the device cordless.
“By enabling real-time observation of free-behaviorable brain activity, this technology not only provides a basic understanding of how the brain processes information and promotes behavior, but also contributes to understanding brain disorders and improving the development of future human treatment strategies.”
