Even light exercise stimulates memory related brain systems.

The evidence for exercise and cognitive health continues to accumulate, including some evidence for increasing blood flow to memory system regions noted here.



Rapid stimulation of human dentate gyrus function with acute mild exercise

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

PNAS published ahead of print September 24, 2018 https://doi.org/10.1073/pnas.1805668115


Our previous work has shown that mild physical exercise can promote better memory in rodents. Here, we use functional MRI in healthy young adults to assess the immediate impact of a short bout of mild exercise on the brain mechanisms supporting memory processes. We find that this brief intervention rapidly enhanced highly detailed memory processing and resulted in elevated activity in the hippocampus and the surrounding regions, as well as increased coupling between the hippocampus and cortical regions previously known to support detailed memory processing. These findings represent a mechanism by which mild exercise, on par with yoga and tai chi, may improve memory. Future studies should test the long-term effects of regular mild exercise on age-related memory loss.


Physical exercise has beneficial effects on neurocognitive function, including hippocampus-dependent episodic memory. Exercise intensity level can be assessed according to whether it induces a stress response; the most effective exercise for improving hippocampal function remains unclear. Our prior work using a special treadmill running model in animals has shown that stress-free mild exercise increases hippocampal neuronal activity and promotes adult neurogenesis in the dentate gyrus (DG) of the hippocampus, improving spatial memory performance. However, the rapid modification, from mild exercise, on hippocampal memory function and the exact mechanisms for these changes, in particular the impact on pattern separation acting in the DG and CA3 regions, are yet to be elucidated. To this end, we adopted an acute-exercise design in humans, coupled with high-resolution functional MRI techniques, capable of resolving hippocampal subfields. A single 10-min bout of very light-intensity exercise (30%V˙O2peak) results in rapid enhancement in pattern separation and an increase in functional connectivity between hippocampal DG/CA3 and cortical regions (i.e., parahippocampal, angular, and fusiform gyri). Importantly, the magnitude of the enhanced functional connectivity predicted the extent of memory improvement at an individual subject level. These results suggest that brief, very light exercise rapidly enhances hippocampal memory function, possibly by increasing DG/CA3−neocortical functional connectivity.

Do dogs use a left temporal speech area for understanding of human language words?



Awake fMRI Reveals Brain Regions for Novel Word Detection in Dogs

Ashley Prichard, Peter F. Cook, Mark Spivak, Raveena Chhibber, Gregory Berns

doi: https://doi.org/10.1101/178186


How do dogs understand human words? At a basic level, understanding would require the discrimination of words from non-words. To determine the mechanisms of such a discrimination, we trained 12 dogs to retrieve two objects based on object names, then probed the neural basis for these auditory discriminations using awake-fMRI. We compared the neural response to these trained words relative to oddball pseudowords the dogs had not heard before. Consistent with novelty detection, we found greater activation for pseudowords relative to trained words bilaterally in the parietotemporal cortex. To probe the neural basis for representations of trained words, searchlight multivoxel pattern analysis (MVPA) revealed that a subset of dogs had clusters of informative voxels that discriminated between the two trained words. These clusters included the left temporal cortex and amygdala, left caudate nucleus, and thalamus. These results demonstrate that dogs' processing of human words utilizes basic processes like novelty detection, and for some dogs, may also include auditory and hedonic representations.

New tidepool and beach at Kapoho.

The volcano creates as well as destroys. The Kapoho lighthouse tower is to the north in the background of the photo.
Credits: Ikaika Marzo of Leilani.

Rescue Palm Tree

In December of 2010, after Christmas, I went to the tide pools at Wai'opae, at Kapoho, on Puna of the Big Island. While walking on the shore around sunset, we found a bunch of about 10 coconuts which had fallen to the black gravel exposed by low tide on the shore. The bunch of coconuts sat below a small grove of coconut trees, one of many which then overhung south Kapoho Bay.

The coconuts were fresh, and it was time for dinner. We will take them with us, I decided, for eating.

We did not eat all ten even that first week, however. After leaving the bunch along the side of the front door of the rented house on Spring Street in Hilo, we soon noted that, by the time we got to the last couple of coconuts, one had sprouted as a baby coconut tree! I decided to put the sprouting coconut out to grow in a large pot we had used for petunias.

A year later, after we'd moved to our current house in 2012, we noted that the front garden bed along the street needed a lot of care. It had become a mixture of newer, invasive shrubs and older, gnarled and bug-bitten azaleas. As part of a renwed border, I decided to plant the yearling coconut near the corner of the lot.

Now, the coconut tree has grown into an adolescent palm tree of about 4 meters height. But what of its ancestors at Kapoho Bay? Those centuries-old groves lie buried, just as of this month, under new lava, as is all of Kapoho Bay! The beautiful tide pools of Wai'opae are gone.

One still stands. Here is the old grove, gone now, and the rescued scion.

Even light exercise stimulates memory related brain systems.

The evidence for exercise and cognitive health continues to accumulate, including some evidence for increasing blood flow to memory syst...