Summary: New research shows that brief, light physical activity—such as yoga, tai chi, or a short walk—can rapidly strengthen communication between brain areas involved in forming and storing memories.
Source: UC Irvine.
Incorporating a short, gentle bout of exercise into your day may help you remember everyday details—like where you left your keys. Scientists at the University of California, Irvine and the University of Tsukuba in Japan report that even very mild physical activity can enhance connectivity between regions of the brain responsible for memory creation and storage.
The study tested 36 healthy young adults and found that a single 10-minute session of light exercise produced measurable cognitive benefits. Using high-resolution functional magnetic resonance imaging (fMRI), researchers examined participants’ brains shortly after these brief activity sessions and observed stronger functional connectivity between the hippocampal dentate gyrus (DG/CA3) and cortical regions associated with detailed memory processing.
The findings were published in Proceedings of the National Academy of Sciences.
“The hippocampus plays a central role in forming new memories; it is among the first brain areas to decline with age, and it is particularly affected in Alzheimer’s disease,” said Michael Yassa, UCI professor and Chancellor’s Fellow of neurobiology & behavior, who co-led the project. “Enhancing hippocampal function could therefore offer practical benefits for everyday memory.”
Importantly, the researchers discovered that the degree of increased connectivity correlated with how much individuals improved on memory tests. In other words, participants who showed the greatest enhancement in DG/CA3–neocortical communication tended to experience the largest gains in recall.
Yassa, director of UCI’s Center for the Neurobiology of Learning and Memory and the UCI Brain Initiative, emphasized that prior work has often focused on how exercise stimulates the growth of new neurons in memory-related regions—a process that unfolds over weeks to months. This new study highlights a more immediate mechanism: brief exercise rapidly strengthens the functional links between memory-focused brain regions.
“We are not ruling out longer-term structural changes such as neurogenesis, which likely contribute over time,” Yassa said. “But here we observed clear effects right after a 10-minute period of light activity.”
Yassa noted that modest amounts of movement can make a difference. “Many people now track daily activity—step counts, short walks, or brief stretching sessions—and these small breaks could substantially benefit memory and overall cognition,” he said.
The research team at UCI and the University of Tsukuba is extending this work to older adults who face greater risk of age-related memory decline. Ongoing studies will test whether daily, brief sessions of light exercise maintained over several weeks or months can produce longer-lasting improvements in brain structure and function in older individuals.
“Determining the most effective exercise ‘prescription’ for older adults could help inform practical recommendations to delay cognitive decline,” Yassa said.
Data collection for the study took place in Japan, and analysis was performed in both Japan and Irvine. The research was led by Michael Yassa (University of California, Irvine) and Hideaki Soya (University of Tsukuba). Joint first authors are Kazuya Suwabe and Kyeongho Byun from the University of Tsukuba.
Funding: Supported by the U.S. National Institutes of Health and Japan’s Ministry of Education, Culture, Sports, Science and Technology.
Source: Brian Bell — UC Irvine
Publisher: NeuroscienceNews.com
Image source: NeuroscienceNews.com (public domain)
Original research: “Rapid stimulation of human dentate gyrus function with acute mild exercise,” by Kazuya Suwabe, Kyeongho Byun, Kazuki Hyodo, Zachariah M. Reagh, Jared M. Roberts, Akira Matsushita, Kousaku Saotome, Genta Ochi, Takemune Fukuie, Kenji Suzuki, Yoshiyuki Sankai, Michael A. Yassa, and Hideaki Soya. Published in PNAS, September 2018. doi: 10.1073/pnas.1805668115
UC Irvine. “Even Mild Physical Activity Immediately Improves Memory Function.” NeuroscienceNews, 25 September 2018.
Abstract
Rapid stimulation of human dentate gyrus function with acute mild exercise
Physical exercise benefits cognitive function, including hippocampus-dependent episodic memory, but the most effective intensity for improving hippocampal performance remains unclear. Previous animal work using a low-stress treadmill model found that mild exercise increases neuronal activity and promotes adult neurogenesis in the dentate gyrus, improving spatial memory. To investigate rapid changes in human hippocampal function, the authors used an acute-exercise design combined with high-resolution fMRI capable of resolving hippocampal subfields. They report that a single 10-minute session of very-light-intensity exercise (approximately 30% V˙O2peak) quickly enhanced pattern separation abilities and increased functional connectivity between the hippocampal DG/CA3 region and cortical areas including the parahippocampal, angular, and fusiform gyri. Moreover, the magnitude of enhanced connectivity predicted the degree of memory improvement at the individual level. These results suggest that brief, very light exercise can rapidly improve hippocampal memory function, potentially by strengthening DG/CA3–neocortical functional connections.