A team from the School of Engineering at The Hong Kong University of Science and Technology (HKUST) has introduced a groundbreaking technology that captures high-resolution images of the brains of awake mice in a nearly noninvasive manner. This innovation eliminates the requirement for anesthesia, thereby allowing scientists to observe brain tissue in its fully functional state. The findings, published in Nature Communications in March 2025, promise to enhance understanding of human brain function in both healthy and diseased conditions, paving the way for new advancements in neuroscience research.
Traditionally, scientists have relied on various imaging techniques such as magnetic resonance imaging (MRI), electroencephalography (EEG), computed tomography (CT), and positron emission tomography (PET). However, these methods often fall short in revealing the intricate details of brain activity. Mice, commonly used as model organisms for studying neurological disorders like Alzheimer’s disease and epilepsy, are especially affected by anesthesia, which can significantly alter blood circulation and neuronal activity. As a result, the data collected from anesthetized animals can yield unreliable results compared to those obtained from awake specimens.
The newly developed technology, known as Multiplexing Digital Focus Sensing and Shaping (MD-FSS), was spearheaded by Prof. QU Jianan of the Department of Electronic and Computer Engineering. This advancement builds on Prof. Qu’s previous work, ALPHA-FSS, which achieved subcellular resolution using three-photon microscopy but struggled with scanning speed and image clarity due to animal movement.
MD-FSS significantly improves the measurement of the point spread function (PSF), which is crucial for creating clear images of brain structures. The innovative method employs multiple weak laser beams, alongside a strong primary beam, to generate nonlinear interference signals within the brain. Each laser beam carries unique spatial information, allowing for rapid and precise PSF measurements in less than 0.1 seconds—over ten times faster than earlier methods.
This technological leap allows researchers to monitor brain activity in real-time, capturing interactions between neurons, glial cells, and blood vessels. The high resolution achievable with multiphoton microscopy enables the observation of individual neurons and even the smallest capillary structures, revealing vital information about brain function.
Prof. Qu noted, “Such detailed, near-noninvasive, and real-time observations in awake animals were previously impossible. With this novel adaptive optics technology, we can now capture the dynamics of neuronal, glial, and vascular interactions at subcellular resolution, free from the confounding effects of anesthesia.”
Furthermore, the scalability of MD-FSS is poised to revolutionize neuroscience research. The current system utilizes eight beams for PSF measurement but can easily expand to accommodate dozens or even hundreds of beams in future iterations. This expansion will facilitate faster imaging across larger brain regions, enhancing research capabilities in understanding rapid brain events, complex network interactions, and disease progression.
Prof. Qu emphasized the significance of this technology, stating, “Our latest work represents far more than an incremental improvement. We now have a versatile platform that can be scaled for faster imaging and integrated with functional assays. This will empower neuroscientists to explore areas such as learning, memory, mental health, and the progression of neurological disorders in ways that were previously unachievable.”
With technological advancements such as MD-FSS, the future of brain imaging looks promising, offering unprecedented opportunities for scientific discovery and a deeper understanding of the complexities of the human brain.