Non-invasive brain stimulation can alter specific brain mechanisms linked to human behavior

For the first time, researchers at the University of Minnesota Twin Cities have shown that non-invasive brain stimulation can change a specific brain mechanism directly related to human behavior. This is an important step forward in the discovery of new therapies to treat brain disorders such as schizophrenia, depression, Alzheimer’s disease and Parkinson’s disease.

The study was recently published in Nature communicationsa peer-reviewed, open-access scientific journal.

The researchers used what’s called “transcranial alternating current stimulation” to modulate brain activity. This technique is also known as neuromodulation. By applying a small electrical current to the brain, the activation time of brain cells is shifted. This regulation of neural timing is related to neuroplasticity, which is a change in the connections between brain cells required for human behavior, learning, and cognition.

Previous research showed that brain activity was time-locked to arousal. What we found in this new study is that this relationship slowly changed and the brain adapted over time as we added external stimulation. This showed that brain activity is changing in a way we didn’t expect.”

Alexander Opitz, Associate Professor, Department of Biomedical Engineering, University of Minnesota

This effect is called “neural phase shift”. This occurs when brain activity changes gradually over time in relation to a repeating pattern, such as an external event or in this case non-invasive stimulation. In this research, all three methods investigated (computer models, humans and animals) showed that external stimulation could shift brain activity over time.

“The timing of this repetitive pattern has a direct impact on brain processes, for example, how we navigate space, learn and remember,” Opitz said.

The discovery of this new technique shows how the brain adapts to external stimulation. This technique can increase or decrease brain activity, but is most powerful when it targets specific brain functions that influence behaviors. In this way, long-term memory as well as learning can be improved. The long-term goal is to use this technique in the treatment of psychiatric and neurological disorders.

Opitz hopes this discovery will help improve knowledge and technology in clinical applications, which could lead to more personalized treatments for schizophrenia, depression, Alzheimer’s and Parkinson’s.

In addition to Opitz, the research team included first authors Miles Wischnewski and Harry Tran. Other team members from the University of Minnesota Department of Biomedical Engineering include Zhihe Zhao, Zachary Haigh, Nipun Perera, Ivan Alekseichuk, Sina Shirinpour, and Jonna Rotteveel. This study was done in collaboration with Dr. Jan Zimmermann, an associate professor at the University of Minnesota Medical School.

This work was primarily supported by the National Institutes of Health (NIH) along with the Behavioral and Brain Research Foundation and the Minnesota State of Minnesota Discovery, Research and Economy Innovation Initiative (MnDRIVE). Computational resources are provided by the Minnesota Supercomputing Institute (MSI).