Glial brain cells, long in neurons’ shadow, reveal hidden powers

We've known for at least a decade that astrocytes and other glia play important roles in synaptic transmission and learning, not just axon insulation and blood-brain-barrier related stuff. It's still unclear what most of their contributions are. They're harder to interrogate because they're not as electrically active as neurons, and though they do exhibit Calcium waves, they're small and seem to be localized to small compartments. There's a number of people out there working on glia in a functional sense, like Atwell at UCL and Magistretti (though he's retired now i think).

In elementary school I had to do a report on Einstein, and I remember one of the important details was that he had a higher ratio of glial cells to neurons than a normal brain.

At the time, they had no idea if this made any difference to his genius, and it sounds like they still aren't too sure.

One of those hidden powers is the destruction of the aging brain. Senescence of glial cells appears to be quite important in the progression of neurodegeneration, as both a source of neuroinflammation and all of its woes, and a mechanism capable of more directly causing neuron death.

Clearance of senescent glial cells prevents tau-dependent pathology and cognitive decline - https://doi.org/10.1038/s41586-018-0543-y

Tau protein aggregation is associated with cellular senescence in the brain - https://doi.org/10.1111/acel.12840

Flushing out 'zombie cells' could help stave off Parkinson's, study suggests - https://www.theguardian.com/science/2018/jan/23/flushing-out...

Astrocyte senescence: Evidence and significance - https://doi.org/10.1111/acel.12937

The good news here is that the senolytic drug dasatinib crosses the blood-brain barrier and has been demonstrated to destroy senescent glial cells in animal models, and destroy senescent cells elsewhere in the body in human trials. The cheap dasatinib / quercetin combination should be trialed in Alzheimer's and Parkinson's patients, and the sooner the better.

I used to have fun trolling by saying "we only think with 10% of our brains". Then as soon as someone comes in thinking they were about to school me real good, I'd drop the fact that 90% of our brains aren't neurons but merely glial support structures so the statistic is technically true. The ol' double cross in pedantic trivia.

I guess I need to stop doing that now.

Went to a conference a couple of years ago where there was an interesting talk on the subject. See here if you are interested:

https://vimeo.com/262522684

Does this mean the connectome is doomed or faulty since it maps only neurons and not glial cells?

Could the glial cells be somehow responsible for backpropagation in the brain?