In a groundbreaking study published in Nature Methods on July 10, scientists have introduced a cutting-edge 4D imaging tool that allows for the analysis of live brain tissue with unparalleled spatial resolution and comprehensiveness.
The technology has the potential to reveal the functional architecture of not only brain tissue but also other organs, shedding new light on the enigmatic nature of subcellular structures and their temporal changes.
The AI-powered tool, known as LIONESS (Live Information Optimized Nanoscopy Enabling Saturated Segmentation), represents a significant leap forward in imaging brain activity.
Developed by Johann Danzl’s group at the Institute of Science and Technology, Austria (ISTA), LIONESS addresses the challenges associated with studying the intricacies of brain tissue, considering its immense complexity and the wealth of information it encompasses.
With approximately 86 billion neurons, the human brain stands as an unparalleled computational marvel.
LIONESS enables researchers to obtain a comprehensive and dense reconstruction of living brain tissue, offering a unique opportunity to observe and measure dynamic cellular biology within the brain.
By imaging the tissue multiple times, LIONESS captures the cellular arrangements in three dimensions, with time constituting the fourth dimension. This flexibility allows for imaging sessions spanning minutes, hours, or even days, leading to an in-depth understanding of cellular dynamics.
The strength of LIONESS lies in its refined optics and implementation of two levels of deep learning, an artificial intelligence (AI) technique. The first step of deep learning, called Image Restoration, fills in missing information about the brain tissue’s structure using minimal sample data.
This real-time imaging approach achieves a remarkable resolution of around 130 nanometers. The second deep learning step analyzes the complex imaging data and automates the identification of neuronal structures.
LIONESS seamlessly integrates functional measurements with structural observations, enabling imaging of calcium ion fluxes and the measurement of cellular electrical activity. Moreover, it benefits from insights obtained through human cerebral organoids, miniature brain models that mimic human brain development.
Traditional techniques for reconstructing brain tissue, such as electron microscopy, provide high resolution at the nanometer scale but require fixing the sample in a specific biological state, preventing the acquisition of dynamic information.
Light microscopy, on the other hand, allows observation of intact tissue but lacks cellular-level resolution. While techniques like Super-Resolution Light Microscopy with SUSHI (Super-resolution Shadow Imaging) and STED (Stimulated Emission Depletion) microscopy have improved resolution, they face challenges related to potential tissue damage caused by intense light.
LIONESS overcomes these limitations by operating under “fast and mild” imaging conditions, ensuring the preservation of the sample’s vitality. This groundbreaking imaging tool holds immense promise for unraveling the mysteries of the brain’s structure and activity, which constantly evolve as it performs and learns new tasks. With its unprecedented capabilities, LIONESS opens up new avenues for advancing our understanding of the brain and its intricate workings.