Wireless Brain Microscope Weighing 1 Gram Tracks 8,500 Neurons in Free-Roaming Mice

Chinese scientists have built a wireless brain microscope weighing just 1 gram that can record the activity of more than 8,500 individual neurons across a mouse’s cortex while the animal roams, climbs, swims and interacts freely with others. The device, called Airscope, was described in a paper published in Nature on 19 October 2026 by a team led by Qionghai Dai of Tsinghua University.

The researchers say Airscope overcomes a long-standing trade-off in neuroscience between how much of the brain a microscope can see and how freely the animal wearing it can move. If the results are confirmed and the technology is widely adopted, it could help scientists study how brain circuits support natural behaviour far more realistically than is possible in a laboratory cage.

What Is Airscope?

Airscope is a head-mounted “mesoscope”, a microscope designed to image a large area of brain tissue at the level of individual cells. According to the Nature paper, it delivers 4 micrometre lateral resolution across a 6 millimetre field of view, captures images at 12.5 frames per second and weighs 1.0 gram.

Rather than relying on a cable, the device uses a tailored wireless link. Xinhua, in a report republished by China’s National Center for Science and Technology Information, said Airscope uses a 2-megapixel image sensor and compresses images on the device so that megapixel-level frames can be transmitted wirelessly. A supplementary video describes battery-powered operation, rapid battery exchange, onboard SD-card storage and a real-time preview over Wi-Fi.

How Does It Compare With Existing Microscopes?

Existing head-mounted microscopes allow animals to move freely, but usually have a field of view of less than 1 millimetre, meaning only a small region of the brain can be seen, Xinhua reported. Larger benchtop microscopes can image wide areas of the cortex, but require the mouse’s head to be fixed in place or tethered by a cable.

The Airscope team says an aspheric-lens design gives the device a total track length, the length of its optical path, 2.84 times shorter than previous miniaturised microscopes, while matching the neuron yield of benchtop one-photon mesoscopes. It can record calcium signals, a proxy for neuron firing, from more than 8,500 neurons per animal, which the authors describe as a 25-fold increase on existing wireless devices.

According to Xinhua, those neurons span 14 cortical areas in one hemisphere of a single mouse, and the device can record from the same site for more than 200 days.

Does Wearing It Affect How Mice Behave?

A key question for any head-mounted device is whether it changes the behaviour it is meant to study. Xinhua reported that mice wearing Airscope could climb ropes and squeeze through tubes, with no significant difference in travel distance, speed or path tortuosity compared with mice without the device. The researchers compared animals with only a head-bar against animals wearing the full device in an open-field arena, according to the paper’s supplementary materials.

These results come from the authors’ own experiments. As with any new technique, independent laboratories will need to test how the device performs in their own set-ups and with other experimental designs.

What Did the Researchers Discover?

The team paired Airscope with an artificial-intelligence tool for analysing behaviour, which the supplementary materials refer to as SAM2Mice. It can segment and track individual mice in video without being specifically trained on each new set-up, a “zero-shot” approach. This allowed the researchers to link brain activity to behaviour across a range of experiments:

• Social dominance: cortical activity patterns across several regions correlated with signs of social dominance, and population activity could predict the outcome of competitions between pairs of mice.
• Maze exploration: researchers observed cortical activity associated with reward locations as mice explored a maze.
• Fear conditioning: using two devices on one animal to record from the brain and spinal cord at the same time, the team characterised how spinal cord activity influenced the cortex.
• Group recording: one experiment recorded five mice at once, capturing 21,397 neurons in total.
• Natural habitats: mice were recorded in a 5-square-metre habitat with shelters, ramps and tree holes.

In that habitat, Xinhua reported, mice moved more than twice as fast as in cages and displayed 16 categories of behaviour, including climbing, using steps and entering holes. Cortical activity changed systematically with the terrain area the mouse was in, and a deep-learning model could identify which area a mouse was in from brain activity alone, with accuracy far above chance.

What Other Experiments Were Run?

The supplementary materials also describe recordings during swimming tests, tail suspension tests and head rotation, as well as imaging of blood vessels in the brain and spinal cord, and combined recordings of pupil and facial movements. One experiment used a head-mounted camera to capture what a mouse saw while its cortex was being imaged.

Why Does This Matter?

“How the brain regulates behaviour in complex natural environments is one of the most fundamental questions in neuroscience,” Xinhua noted, adding that such research has been constrained by the trade-off between the number of neurons that can be observed and the weight of the microscope.

“Airscope provides greater behavioural freedom for neuroscience research and allows large-scale neural observation to follow animals into richer natural behaviours, helping us better study brain cognition and brain diseases,” said Zhang Yuanlong, an assistant professor at Tsinghua University’s School of Life Sciences and a lead author of the paper.

Dai said the microscope offers a new tool for understanding the neural basis of intelligence and could help advance optical brain-computer interfaces. He suggested future applications might extend beyond neuroscience to fields such as immunology and oncology, though those uses have not yet been demonstrated.

What Are the Limitations?

The research was carried out in mice, and the experiments described focus on the dorsal surface of the cortex rather than deeper brain structures. Calcium imaging requires animals to be genetically modified or treated so that their neurons produce fluorescent signals, and a surgical implant is needed. The work is not directly applicable to people. Claims about potential uses in brain-computer interfaces or disease research should be treated as long-term possibilities rather than near-term applications.

Who Was Involved?

The paper’s joint first authors are Yuanlong Zhang, Angran Li, Lekang Yuan, Mingrui Wang and Weihao Zhao. The corresponding authors are Jiamin Wu, Pu Dai and Qionghai Dai. Contributors are based at Tsinghua University, Fudan University, Zhongguancun Academy, Princeton University, Northeastern University in Shenyang and the Chinese PLA General Hospital’s Sixth Medical Center.

The team has published online documentation that describes open-source circuit boards, a 3D-printed housing, a device assembly guide, analysis software including SAM2Mice, and a public data release, with code hosted on GitHub. The documentation lists four design features: the aspheric optics, a side-illumination layout for the LEDs said to save about 30% of the device’s volume, wireless streaming above 1 megapixel, and flexible circuit boards that keep total weight to 1 gram. Some figures in the documentation, such as a 10 Hz frame rate, differ slightly from the published paper, which gives 12.5 Hz. The authors describe Airscope as “a broadly accessible technology for systems neuroscience”. How easily other laboratories can build and use the device will be a key test of that claim.

The work also reflects the growing use of AI in science, from analysing behaviour to extracting neuron signals from images. For more on how AI is changing research and industry, see our report on EU AI adoption across strategic industries.

What to Watch

• Independent replication: whether other laboratories can reproduce the results with their own devices.
• Open hardware: how much of the design is shared and how widely it is adopted.
• Deeper imaging: efforts to extend wireless imaging beyond the cortical surface.
• Disease research: whether the device is used to study models of brain disorders.
• Brain-computer interfaces: any steps towards using optical readouts in BCI research.

For more, see our Science News section.

Sources

• Nature — Cortex-wide imaging in naturally behaving mice with 1-gram wireless mesoscopes (19 October 2026).
• National Center for Science and Technology Information (Xinhua) — Chinese team invents 1-gram microscope for precise neural detection (20 October 2026).
• Tsinghua University BNRist — Airscope announcement (in Chinese).
• Airscope Documentation — Airscope hardware and software documentation.