Scientists have developed a tiny, flexible brain implant that can perform three functions at once: record electrical activity, deliver drugs, and stimulate neurons with light.

The device, called the microfluidic Axialtrode, or mAxialtrode, could give researchers a new way to study how different layers of the brain communicate and how neural circuits respond to targeted interventions.

Its developers say the technology may eventually have therapeutic applications for neurological conditions such as epilepsy, where precisely monitoring and manipulating abnormal brain activity could be valuable. However, the device remains experimental and has so far only been tested in mice.

The researchers believe its ability to combine neural recording, drug delivery, and optical stimulation in a single, flexible implant could make it a useful tool for studying complex brain processes. The findings were published in Advanced Science.

How Does the Brain Implant Work?

The mAxialtrode is a needle-thin fibre measuring less than half a millimetre across. Unlike conventional brain implants that may interact with tissue primarily at one location, the new device has multiple functional points along its length.

At its centre is a light-conducting core, surrounded by eight microscopic channels. These channels can transport liquids for drug delivery and also accommodate extremely thin metal wires capable of recording electrical activity.

The researchers designed the device to be highly flexible, allowing it to move with brain tissue. Its soft, plastic-like optical fibre and specially angled tip are intended to reduce the tissue damage associated with inserting and keeping a rigid implant in the brain.

This could be particularly useful for experiments that require researchers to monitor or manipulate activity at several depths rather than focusing on a single brain region.

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One Device Can Perform Multiple Functions

In experiments involving living mice, researchers used the mAxialtrode to stimulate neurons with both blue and red light while simultaneously recording electrical activity from different parts of the brain.

The device allowed scientists to monitor activity in areas including the cerebral cortex and hippocampus, which is involved in processes such as learning and memory.

Researchers could also deliver different substances to separate locations, with delivery points positioned almost 3 millimetres apart. The ability to combine drug delivery, light stimulation, and electrical recording within a single lightweight fibre could allow scientists to investigate how neural circuits behave across different layers of the brain.

The technology could be particularly useful in studying conditions such as epilepsy, as well as brain processes involved in memory and decision-making.

Could It Eventually Treat Brain Disorders?

The potential medical applications are among the most intriguing aspects of the technology, but researchers stress that the device is still experimental.

In the future, a similar implant could potentially deliver medication directly to a specific area of the brain while simultaneously stimulating or monitoring neural activity. Such an approach could offer more precise control than using separate devices for each function.

However, there is currently no evidence that the mAxialtrode can safely treat neurological conditions in humans. The successful experiments were conducted in mice, and substantially more research would be needed to establish its safety, effectiveness, and long-term effects in people.

The researchers are now exploring the requirements for eventually testing the technology in patients and are working to patent the brain electrode.

For now, the mAxialtrode represents a research platform rather than an available medical treatment. If further studies confirm its safety and reliability, its ability to combine several functions in one flexible implant could open new possibilities for understanding and, potentially, treating disorders involving complex brain circuits.

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