New microscope visualizes brain activity at the cell scale

Nov. 6 () –

Cornell researchers have presented an imaging technology capable of visualizing brain activity in an unprecedentedly wide and deep field with single-cell resolution.

The innovative microscope, called DEEPscope, combines two- and three-photon microscopy techniques to capture large-scale neuronal activity and structural details that were previously inaccessible. It is featured in E Light magazine.

Traditional multiphoton microscopy, a cornerstone for deep tissue imaging, faces significant limitations in imaging depth and field of view, especially in highly dispersed biological tissues such as the brain.

To avoid thermal damage, image depth is typically increased at the expense of an exponentially decreasing field of view, which makes it difficult to observe large-scale neural networks.

DEEPscope addresses these limitations by integrating a suite of novel techniques, allowing researchers to visualize extensive brain regions at unprecedented depths.

Key to this advancement is DEEPscope’s adaptive excitation system and multi-focus polygon scanning scheme, that allow efficient generation of fluorescence to obtain large field of view images.

These innovations enable high-resolution imaging in a 3.23 x 3.23 mm2 field with an imaging speed sufficient to capture neuronal activity in the deeper cortical layers of the mouse brain. The ability to perform simultaneous two- and three-photon imaging further enhances the versatility of the system, allowing detailed exploration of both deep and superficial regions.

In their study, the researchers demonstrated DEEPscope’s ability to image entire cortical columns and subcortical structures at single-cell resolution. They successfully recorded neuronal activities in the deep brain regions of transgenic mice, observing more than 4,500 neurons in the deep and superficial cortical layers.

Additionally, DEEPscope enabled whole-brain imaging of adult zebrafish, capturing structural details at depths greater than 1 mm and in a wider field of 3 mm, a first in the field of neuroscience.

“DEEPscope represents a significant advance in brain imaging technology,” said Aaron Mok, lead author of the study. “For the first time, we can visualize complex neural circuits in living animals at such a large scale and depth, allowing us to better understand brain function and potentially opening new avenues for neurological research“.

The demonstrated techniques can be easily integrated into existing multiphoton microscopes, making them accessible for widespread use in neuroscience and other fields requiring deep tissue imaging, according to the researchers.

By overcoming previous limitations, DEEPscope sets a new standard for wide-field, high-resolution deep imaging of living tissues, which promises to advance our understanding of the brain’s intricate networks and their role in health and disease.