Multi-pupil prism arrays used in brain imaging systems

The brain is the most complex organ and extensive research is going on to understand the way it functions. A research team at the Purdue University has developed a technology that enables viewing and analyzing the activity of several cells concurrently, collecting large amounts of information that was formerly only obtainable for tiny cell groups.

A dedicated kind of adaptive-optics technology that has been illustrated by capturing high-resolution time-lapse pictures of working brain cells can be used to better comprehend the functioning of the brain. The technique has the potential to display altering biological processes details in cells over a bigger field, enabling high-throughput that is vital for studying the activity of the brain.

The technology, known as multi-pupil adaptive optics, depends on deformable mirrors that modify shape to neutralize the deformation caused when light travels via biological tissue, and a prism array consisting of several faceted segments. Every segment generates its own image equivalent to a diverse component of the field of view of a microscope.

The team utilized the system to map the brain cells known as microglia; vasculature in the brain; signaling processes of neurons involving calcium; and dendritic spines, anatomies in neurons important to communication and learning between brain cells.

Living tissue and cells consist of a complex blend of materials and structures, all having a diverse refractive index, which describes how fast light passes while traveling through materials. Due to this heterogeneity, the light passing through cells creates blurred images. Devices known as spatial light modulators in the adaptive optics tools are capable of contradicting this distortion by altering the shape on applying voltage, adapting for the differences in refraction. However, the traditional adaptive optics equipment is limited as they have the potential to image only tiny areas at a time.

But, multi-pupil adaptive optics resolves this issue. The preliminary research utilized a 3-by-3 prism array consisting of 9 segments, all of them approximately a square centimeter. The multi-pupil adaptive optics’ present version is about 10 times better than traditional techniques. However, the performance can be enhanced by elevating the size of these arrays to include around 36 segments.

We hope that this technology provides us more insights about the functioning of the brain.