A shot to replace exercise?

Back when I was first investigating exercise to address my disease, I came across this article in Scientific American that discussed what was going on in the brain during physical exercise that might help the brain.  It did not mention by name the brain-derived neurotrophic factor (BDNF) that we discussed in Beating the Dementia Monster, but it described its effects, such as prompting stem cells in the hippocampus to form new neurons ... among other benefits.  The article proposed that it might be possible to artificially replicate the healing environment which appears in the brain during exercise.

What would be the benefit of that?  Hey, you could pop a pill and not need to go to the gym anymore!  What more could you ask!

A recent article in SciTechDaily.com reported on research for a possible way to just do that.  The article was entitled "Brain Gains: Scientists Discover How To Replicate the Cognitive Benefits of Exercise," and it reported on research conducted at the University of Queensland and published in the journal Nature Communications.  The journal article was entitled "Platelet-derived exerkine CXCL4/platelet factor 4 rejuvenates hippocampal neurogenesis and restores cognitive function in aged mice."  (Mice again.)

Some music to our ears: the researchers underlying understanding was that physical exercise is one of the strongest enhancers of adult hippocampal neurogenesis, and older adults who perform regular physical activity are more likely to maintain their cognitive ability.  (Neurogenesis is the generation of new brain cells from stem cells.)  

They must have read Beating the Dementia Monster. 

So what's the concept here?  The idea is that during exercise, blood platelets excrete a specific "exerkine" that has the power to prompt stem cells in the brain to form new neurons ... among other benefits.  The researchers acknowledged that this is a similar effect to BDNF, and the presence of BDNF in an exercising brain could confound research results.  But mice brains don't produce BDNF.

According to this article, exerkines are defined as signalling molecules released in response to acute and/or chronic exercise, which exert their effects through certain pathways.  A multitude of organs, cells, and tissues release these factors, including skeletal muscle, the heart, liver, white adipose tissue, brown adipose tissue, and neurons.  Not mentioned in this definition is blood platelets.  But it does help illustrate why exercise has such a great benefit for so very many aspects of your health! 

What the Australian researchers found was that "the systemic administration of the platelet-released exerkine PF4 in an adult hippocampal neurogenesis-dependent manner" could reproduce the cognition-enhancing benefits of exercise in aging mouse brains.  Basically, they extracted the exerkine PF4 from the platelets of exercising mice and injected it into veins in the tails of aging mouse subjects.  They tested the mice for their ability to learn and then evaluated changes in brain volume.  This treatment improved cognitive ability and increased brain volume.

That was with mice.  Will the same thing happen with people?  The research paper didn't address application of this method on human subjects.  However, the researchers made some brief statements to the journalists with SciTechDaily.  They said that the next step is to study the effect of administering exerkines to diseased mice, since the initial research was with healthy mice, both young and aging.  After that would come some sort of human trials.  Throughout the research paper and interviews, the researchers stayed away from suggesting that this treatment will actually replace exercise.  So keep your gym membership current.