In a study published in eLight, researchers from Cornell University revealed an new imaging technology that can visualize brain activity at single-cell resolution.
Illustration of multi-focus scanning with DEEPscope, imaging a neuron deep within the brain. Image Credit: Aaron T. Mok, Tianyu Wang, Shitong Zhao, Kristine E. Kolkman, Danni Wu, Dimitre G Ouzounov, Changwoo Seo, Chunyan Wu, Joseph R. Fetcho, Chris Xu
DEEPscope, the cutting-edge microscope, combines two-photon and three-photon microscopy techniques to capture large-scale neural activity and structural details that were previously inaccessible.
Traditional multiphoton microscopy has been a powerful tool in deep-tissue imaging for many years, yet it struggles with imaging at depth and has a limited field of view, especially when imaging highly scattering tissues like the brain.
Balancing these constraints, researchers often push imaging depth at the cost of a dramatically reduced field of view to avoid thermal damage. This trade-off, however, limits large-scale observation of neuronal networks. DEEPscope was designed to tackle these exact challenges, introducing a set of innovative methods that expand imaging capability to reveal large brain regions at remarkable depths.
At the core of DEEPscope's advancements are its adaptive excitation system and multi-focus polygon scanning approach, which improve fluorescence efficiency across an extensive field of view. These technologies allow for high-resolution imaging over a 3.23 x 3.23-mm2 field, capturing neuronal activity within the deepest cortical layers of mouse brains. Moreover, the ability to conduct simultaneous two-photon and three-photon imaging enhances DEEPscope's flexibility, enabling detailed imaging across both superficial and deep tissue layers.
In practical application, the researchers showcased DEEPscope’s ability to image complete cortical columns and subcortical structures with single-cell precision. They recorded neuronal activity across deep brain regions in transgenic mice, visualizing over 4,500 neurons from shallow to deep cortical layers.
In a breakthrough for whole-brain imaging, DEEPscope also successfully mapped the adult zebrafish brain, capturing structural details at depths beyond 1 mm across a field exceeding 3 mm—setting a new benchmark in deep-tissue neuroscience imaging.
DEEPscope represents a significant advancement in brain imaging technology. 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.
Aaron Mok, Study Lead Author, School of Applied and Engineering Physics, Cornell University
The innovative techniques behind DEEPscope are designed for seamless integration with existing multiphoton microscopes, making advanced imaging capabilities widely accessible to neuroscience labs and other fields that rely on deep-tissue imaging.
By addressing past limitations in depth and field of view, DEEPscope sets a new benchmark for large-field, high-resolution imaging in living tissues. This leap in technology has huge potential, offering new insights into the brain’s complex networks and their implications for health and disease.
Journal Reference:
Mok, A. T. et. al. (2024) A large field-of-view, single-cell-resolution two- and three-photon microscope for deep and wide imaging. eLight. doi.org/10.1186/s43593-024-00076-4