Five Grams for Brain Research: A New-Generation Miniature Microscope Has Been Developed

The device weighs just 5 grams and is mounted directly on the animal’s head. The technology could help scientists better understand how the brain controls behavior and investigate the mechanisms underlying neurological diseases. The findings were published in the journal Optica.

The new microscope, called Opto2P-FCM, combines high-resolution imaging with optical stimulation of individual neurons — the use of light to selectively activate specific cells.

This sets the device apart from many existing miniature microscopes. While such systems allow scientists to monitor brain activity in freely moving animals, they often provide lower image quality than larger laboratory systems or do not allow researchers to simultaneously manipulate specific neurons.

“This microscope is a game changer,” said study co-author Juliet Gopinath, a professor at the University of Colorado Boulder.

For decades, two-photon microscopy has been one of the main tools for obtaining detailed images of living brain tissue. However, the technique typically requires the animal to remain stationary. This significantly limits researchers’ ability to study the brain during movement and other natural behaviors.

The new system addresses this limitation by using two separate optical channels. One is responsible for capturing clear images of the brain, while the other directs light onto selected neurons to activate them.

By separating these functions, researchers can simultaneously observe the activity of nerve cells and determine how changes in the activity of specific neurons affect other cells and behavior.

Developing such a device presented a complex engineering challenge. With a total weight of just 5 grams, the designers had to carefully consider the position and precision of every component, including the miniature optical elements.

According to the researchers, the new technology could be used to study disorders associated with impaired neural network function, including Alzheimer’s disease, Parkinson’s disease, and epilepsy.

The device is still a prototype. In the future, the team plans to make it even smaller and lighter, increase its operating speed, and expand its field of view.

The researchers hope that the technology will enable scientists not only to observe how the brain works but also to precisely manipulate the activity of individual cells, helping them understand how interactions between neurons shape behavior and what changes occur in neurological diseases.