Meditating Mice Show How Mindfulness Can Change the Cells of the Brain

Meditation's power is more than psychological.


University of Oregon neuroscientist Michael Posner, Ph.D. doesn’t want you to think he’s found a way to make mice meditate] to study the biological benefits of mindfulness, but he understands why you might ask. Posner is the lead author of a new PNAS paper showing that meditation can actually change the makeup of the brain. “Sometimes people wonder how we get mice to meditate,” he tells Inverse.

“The answer is we don’t,” Posner continues, explaining the basis of his team’s paper, published Monday. “We study the brain effects of human learning, including meditation, and develop an animal model where we can precisely test the relevant hypothesis.”

In the study, he and his team were able to simulate the neurological effects of meditation in mice using electric implants. So, strictly speaking, the mice didn’t know they were meditating — their brains were just doing it. And while the mice were subconsciously meditating, Posner and his team found that their brain cells were producing more of a crucial compound that improves connectivity, adding to a growing body of evidence that meditation has quantifiable, positive effects on the brain.

Researchers can make mice "meditate" by implanting these light-sensitive fibers in their brains. The mice are genetically manipulated so when light is passed through the fibers, it can trigger responses in their brain cells. 

John P. Carnett/Popular Science/Getty Images 

That crucial material is myelin, a fatty covering that encases the part of a neuron called the axon. Brain cells send signals to each other via electrical signals, and the axon is the wire through which those signals are conducted. Like telephone and internet cables, these wires need insulation — which is exactly what myelin does, allowing electrical impulses to travel continuously along it. Posner found that after his rats “meditated,” the myelin-producing cells, called oligodendrocytes, were particularly active in two areas of the brain, mirroring the effects he saw in an earlier study on humans.

“Many meditation methods produce an increase in theta rhythms across the frontal cortex of humans,” Posner says. “We also demonstrated increased cellular activity in the human anterior cingulate cortex following meditation training.”

The “theta rhythms” Posner describes are simply recurring patterns of neuron firings that researchers can see on EEG readings. In short, they’re brain waves. In his previous study, Posner noticed that when humans perform certain kinds of meditation, their brains produce theta rhythms. In the new study, he showed that, at least in mice, it was these low-frequency waves that actually stimulated myelin production, which in turn improved axon connectivity and led to some behavioral changes. The mice became more “exploratory,” preferring to wander into the better-lit portions of a two-compartment box.

Researchers still aren't sure how theta rhythms can promote myelin production. It could help create new ogliodendrocytes, or it could help existing ones produce myelin more efficiently. 


This study was one of a series of investigations into a type of “mindfulness training” called Integrative Body Mind Training (IBMT), which integrate techniques like body relaxation and mental imagery in order to enhance self-regulation, attention span, emotional regulation, and self awareness. Posner’s study suggests meditation might qualify as a form of IBMT, though even IBMT itself is still loosely defined: So far, a 2011 Neuroscience Bulletin study suggests that it involves “no effort to control thoughts,” and a 2017 review in Frontiers in Psychology notes that it usually includes some type of soft music and guidance from an instructor.

There are plenty of studies that poke holes in “mindfulness science” and the therapeutic benefits of meditation, in which critics argue that the claims of the mindfulness “industry” are not supported by any conclusive research. Posner’s study adds to the small but steadily increasing body of evidence that mindfulness has quantifiable effects on the body, but more research will have to be done before we can draw any conclusions. In the meantime, if meditation doesn’t appeal to you but its effects do, maybe try convincing a researcher to implant a light-sensitive electrode in your brain.

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