Stimulating a certain region of the brain using magnetic pulses could help improve memory.
The finding could help lead to new treatments for memory impairments caused by conditions such as early-stage Alzheimer's and traumatic brain injury, and aging, Northwestern University reported.
"We show for the first time that you can specifically change memory functions of the brain in adults without surgery or drugs, which have not proven effective," said senior author Joel Voss, assistant professor of medical social sciences at Northwestern University Feinberg School of Medicine. "This noninvasive stimulation improves the ability to learn new things. It has tremendous potential for treating memory disorders."
The study is the first to demonstrate that remembering events requires a number of brain regions to work with the hippocampus in a similar fashion to a symphony orchestra. The electrical stimulation is like providing the brain with a more talented conductor.
"It's like we replaced their normal conductor with Muti," Voss said, referring to Riccardo Muti, the music director of the renowned Chicago Symphony Orchestra. "The brain regions played together better after the stimulation."
The hippocampus is too deep in the brain to be directly stimulated by TMS, but the researchers identified a superficial brain region a centimeter from the skull's surface with high connectivity to the hippocampus; direct stimulation of this spot also stimulated the hippocampus.
To make their findings the researchers looked at 16 healthy adults between the ages of 21 and 40. Each participant had detailed anatomical image taken of their brains and their brain activity recorded for 10 minutes.
"To properly target the stimulation, we had to identify the structures in each person's brain space because everyone's brain is different," Voss said.
The participants underwent a daily 20 minutes of deep brain stimulation for five days; they received a week of placebo treatments either before or after the authentic ones.
"They remembered more face-word pairings after the stimulation than before, which means their learning ability improved," Voss said. "That didn't happen for the placebo condition or in another control experiment with additional subjects."
MRIs showed the stimulation caused the regions of the brain to become more synchronized with eachother and the hippocampus.
The more certain brain regions worked together because of the stimulation, the more people were able to learn face-word pairings," Voss said.
The study was published August 29 in Science.
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