Brain repair and reversal of neurodegenerative diseases
Neurodegenerative diseases are some of the most destructive to the human lifespan. There are many ways that our bodies can be damaged, but when we lose our cognition, our memory, our sense of self, that’s the deepest blow. For a long time, the brain was thought to be quite static in adulthood. In fact for a VERY long time, it was believed that the adult brain could not grow new neurons. Now we know that’s not true (but it takes forever to undo those initial assertions).
The brain is a closed system and at times it can be challenging to determine how to repair it without compromising the whole. There are a few ways of thinking about brain repair in the context of insults (like stroke) and neurodegenerative diseases.
The first is upstream, before the start of any diseases or incidents, keeping the brain in an optimal functional and flexible state. Although it seems odd, it appears that exercise has a neuroprotective effect on the brain. It’s the kind of exercise that most people can do, walking or jogging, that appears to maintain the vasculature in the brain and support neurogenesis.
Once damage has occurred, there are both pharmacological and nonpharmacological routes to consider. Using neuromodulation it’s possible to jump start areas of the cortex or other aspects of the peripheral nervous system into plasticity so that function may be recovered. This is exciting because it is minimally invasive and can be used at home. In the pharmacological realm, researchers are beginning to look at compounds that increase or induce neuroplasticity to address brain repair. Psychedelics have also been evaluated for their plasticity-inducing effects, typically associated with mental health, but also neurodegeneration. Other compounds, like GDF11, have been associated with parabiosis, infusing “young” blood into older animals for beneficial effects. It appears that these effects may extend to the brain, and could be used as a post-ischemic stroke treatment. These treatments are all feasible within the next decade.
The holy grail would be the complete repair of brain tissue, which might be possible through stem cells. This is currently not a solved problem; it will require additional research and a much deeper understanding of how new neurons could migrate to and integrate with otherwise damaged tissue. These therapies are seen as much more viable in the context of neurodegenerative diseases that target specific populations of neurons, like ALS or Parkinson’s disease. We have yet to find therapies to reverse dementia, which includes Alzheimer’s disease, Lewy body dementia, and others. The hope is that with earlier detection of dementia, through the use of machine learning and other big data techniques, we will be afforded the opportunity to intervene much earlier in the neurodegenerative process. Even now, research teams are working on vaccines and antibodies against the misfolded proteins in these diseases in the hope of eliminating them from the brain altogether. Alas, these solutions seem a decade off or more, but are currently under intense work and funding to bring them nearer term.