A new tool engineered by researchers from the University of Lethbridge, Canada, and the University of Minnesota enables analysis of neural activity in specific regions of the brain’s cortex. The mini-mScope could expand insight into human brain conditions such as concussions, autism, Alzheimer’s and Parkinson’s disease.

The head-mounted fluorescence microscope images an area about 10 mm by 12 mm and weighs about 3 g. The instrument was tested with mice, which have similar brain structures and connectivity properties as humans. Images captured at near cellular level facilitates evaluation of connections between regions across the cortex.

The calcium-imaging microscope was demonstrated to image mouse brain activity in response to a visual stimulus to the eye, a vibrational stimulus to the hindlimb and a somatosensory stimulus presented to the whisker. Functional connectivity maps of the brain were constructed with data generated from a mouse wearing the head-mounted microscope as it interacted with another mouse. Intracortical connectivity was observed to increase when the animal engaged in social behaviors with the other mouse.Components and structure of the miniaturized, head-mounted microscope for studying the mouse brain. Source: Mathew L. Rynes et al./University of MinnesotaComponents and structure of the miniaturized, head-mounted microscope for studying the mouse brain. Source: Mathew L. Rynes et al./University of Minnesota

The downsized microscope uses LEDs for illumination, miniature lenses for focusing and a complementary metal-oxide-semiconductor for capturing images. Interlocking magnets enable attachment to structurally realistic 3D-printed transparent polymer skulls implanted into mice to form a window through which long-term microscopy can be performed.

The researchers are now using the mini-mScope to investigate how cortical connectivity changes in different behavioral paradigms and to improve the imaging resolution.

A paper on this research is published in Nature Methods.

To contact the author of this article, email shimmelstein@globalspec.com