Ultrasound Treatment May Improve Memory in Mice by Provoking Neurogenesis

There has been some research into the use of ultrasound for short-term disruption of the blood-brain barrier, to allow medication through without excessive delivery of unwanted materials into the central nervous system. In the course of this line of work, researchers observed that ultrasound treatments resulted in improved cognitive function in mice. Here, it is suggested that this has nothing to do with the blood-brain barrier effects, but instead it is in some way upregulating neurogenesis, the production of new neurons and their integration into neural circuits in memory-related areas of the brain. The present view on neurogenesis is that more of it would be a good thing, even in youth, and the decline of neurogenesis with age is an unfortunate outcome that should be prevented. Might suitable ultrasound treatments have a large enough effect to matter in humans? Perhaps; it is certainly an interesting proposal.

The idea that sound waves knocking at the skull could boost memory continues to sound far-fetched to many Alzheimer's researchers, but researchers report that scanning ultrasound improved synaptic signaling, increased neurogenesis, and sharpened spatial memory in old wild-type mice. Importantly, this worked without breaching the blood-brain barrier, a commonly used ultrasound trick to provoke a brain response. Whether this technique is appropriate for people remains to be seen, though early stage clinical trials in older adults indicate it may be safe.

Previous work had suggested ultrasound somehow opens TRPA1 calcium channels in astrocytes, which then release glutamate to activate NMDA receptors on nearby neurons. Researchers looked for signs of astrocyte-mediated activation in mouse hippocampal tissue via Western blots, and found that tissue from mice exposed to ultrasound contained more TRPA1 than tissue from control.

Evidence of NMDA activation came when the scientists separated hippocampal tissue into total and postsynaptic fractions. In the postsynaptic fraction, ultrasound had bumped up the amount of NR2B, a subunit of NMDA receptors that is needed for long-term potentiation (LTP), a form of synaptic plasticity. LTP is crucial for learning and memory and by 20 months of age, it has faded. However, the scanning ultrasound had restored LTP in aged mice, as judged by evoked potentials in hippocampal slices. Based on dentate gyrus expression of doublecortin, a marker of new neurons, the authors concluded that ultrasound upped neurogenesis 13-fold. The scientists did not track how long the memory changes lasted. "Because there are changes at the NDMA receptor level, my gut feeling is that ultrasound leads to long-lasting changes."

Link: https://www.alzforum.org/news/research-news/no-breach-needed-ultrasound-improves-memory-mice



Pituitary gland aging can potentially be slowed down

Stem cell biologist Hugo Vankelecom (KU Leuven) and his colleagues have discovered that the pituitary gland in mice ages as the result of an age-related form of chronic inflammation. It may be possible to slow down this process or even partially repair it. The researchers have published their findings in PNAS.

The pituitary gland is a small, globular gland located underneath the brain that plays a major role in the hormonal system, explains Professor Hugo Vankelecom from the Department of Development and Regeneration at KU Leuven. "My research group discovered that the pituitary gland ages as a result of a form of chronic inflammation that affects tissue and even the organism as a whole. This natural process usually goes unnoticed and is referred to as 'inflammaging'-a contraction of inflammation and aging. Inflammaging has previously been linked to the aging of other organs." Due to the central role played by the pituitary, its aging may contribute to the reduction of hormonal processes and hormone levels in our body-as is the case with menopause, for instance.

The study also provides significant insight into the stem cells in the aging pituitary gland. In 2012, Vankelecom and his colleagues showed that a prompt reaction of these stem cells to injury in the gland leads to repair of the tissue, even in adult animals. "As a result of this new study, we now know that stem cells in the pituitary do not lose this regenerative capacity when the organism ages. In fact, the stem cells are only unable to do their job because, over time, the pituitary becomes an 'inflammatory environment' as a result of the chronic inflammation. But as soon as the stem cells are taken out of this environment, they show the same properties as stem cells from a young pituitary."

Posted by: Robert Read at June 15th, 2021 10:53 AM

This ultrasound idea is weird, but at least it is easy. Just stick the machine on your head and hit the button. Instant IQ boost!

Posted by: Paul at June 15th, 2021 10:50 PM

The ultra sound is kinda a mini massage that could be enhancing the blood flow. One huge difference between the mice and us is that our heads are hm... huge compared to the murine ones . Sending ultrasound across the whole human brain will be much more challenging. But hey , if it helps even marginally why not. Now we need human studies...

Posted by: Cuberat at June 16th, 2021 3:52 PM
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