New Microscope Offers Unprecedented Deep and Wide-Field Visualization of Brain Activity at Single-Cell Resolution

To enhance imaging depth while preventing thermal damage, the field of view often diminishes exponentially, complicating the observation of extensive neuronal networks. Now, a groundbreaking microscope has been developed to overcome these limitations by incorporating a range of innovative techniques, enabling researchers to visualize vast areas of the brain at unmatched depths.

A research team at Cornell University (Ithaca, NY, USA) has introduced an advanced imaging technology that offers exceptional deep and wide-field visualization of brain activity at single-cell resolution. This microscope, known as DEEPscope, merges two-photon and three-photon microscopy techniques to capture expansive neural activity and structural details that were previously difficult to access. A key aspect of this advancement is DEEPscope’s adaptive excitation system along with its multi-focus polygon scanning scheme, which facilitates efficient fluorescence generation for large field-of-view imaging. These features enable high-resolution imaging over a 3.23 x 3.23-mm² area with sufficient speed to record neuronal activity in the deepest layers of mouse cortical tissue. Additionally, the capacity for simultaneous two-photon and three-photon imaging increases the system's versatility, enabling detailed investigations of both superficial and deeper brain regions.

In a study published in the journal eLight, the researchers demonstrated DEEPscope’s ability to image entire cortical columns and subcortical structures with single-cell resolution. They successfully recorded neuronal activity in deep brain regions of transgenic mice, observing more than 4,500 neurons across both shallow and deep cortical layers. Furthermore, DEEPscope facilitated whole-brain imaging in adult zebrafish, capturing structural details at depths exceeding 1 mm and across a field greater than 3 mm—an achievement unprecedented in neuroscience. The techniques demonstrated can be seamlessly integrated into existing multiphoton microscopes, making them accessible for broad applications in neuroscience and other disciplines that require deep-tissue imaging. By addressing previous constraints, DEEPscope establishes a new benchmark for large-field, high-resolution, deep imaging of living tissues, with the potential to enhance understanding of the brain’s complex networks and their significance in health and disease.

“DEEPscope represents a significant advancement in brain imaging technology,” said Aaron Mok, the study's lead author. “For the first time, we can visualize complex neural circuits in living animals at such a large scale and depth, providing insights into brain function and potentially opening new avenues for neurological research.”