Scientists have developed a new technique to activate brain cells outside of the body, which they hope could pave the way for treatments for conditions such as depression.

The early-stage research in rats involved brain cells called astrocytes being stimulated externally using tiny micro-magnets, in a process called magnetomechanical stimulation.

The experts, led by a team at University College London (UCL), hope the treatment may also lead to future, more gentle, therapies for a range of other neurological disorders, including epilepsy.

The work, published in Advanced Science, describes how the magnets can be used as switches to turn “on” the cells when a strong magnet is placed near the head.

Co-author Professor Alexander Gourine said: “Astrocytes are star-shaped cells found throughout the brain.

“They are strategically positioned between the brain blood vessels and nerve cells.

“The ability to control brain astrocytes using a magnetic field gives researchers a new tool to study the function of these cells in health and disease that may be important for future development of novel and effective treatments for some common neurological disorders, such as epilepsy and stroke.”

Senior author Professor Mark Lythgoe added: “Because astrocytes are sensitive to touch, decorating them with magnetic particles means you can give the cells a tiny prod from outside the body using a magnet, and as such, control their function.

“This ability to remotely control astrocytes provides a new tool for understanding their function and may have the potential to treat brain and mood disorders, including depression.”

Lead researcher Dr Yichao Yu said: “Our new technology uses magnetic particles and magnets to remotely and precisely control brain cell activity and, importantly, does this without introducing any device or foreign gene into the brain.

“In the laboratory-based study, we coated microscopic magnetic particles with an antibody that enables them to bind specifically to astrocytes. The particles were then delivered to the target brain region in the rat via injection.

“Another advantage of using micromagnets is that they light up on an MRI scan so we can track their location and target very particular parts of the brain to get precise control of brain function.”