Two structurally connected brain regions are more likely to interact, with the lengths of the structural bundles, their widths, myelination, and the topology of the structural connectome influencing the timing of the interactions. We introduce an in vivo approach, based on neuronal avalanches, for measuring functional delays across the whole brain in humans using magneto/electroencephalography and integrating them with the structural bundles. The resulting topochronic map of the functional delays/velocities shows that neuronal avalanches spread more quickly when they travel across larger (and likely more myelinated) white-matter bundles. Then, we estimated the topochronic map in multiple sclerosis patients, who have damaged myelin sheaths, and controls, demonstrating greater delays in patients across the network and that structurally lesioned tract were slowed down more than unaffected ones. In conclusion, we apply the framework of criticality to provide a novel framework for integrating tractography and magnetoencephalography, with the scope of estimating functional transmission delays in vivo at the single-subject and single-tract level.
Hi, I think we got disconnected! Is there a new link for zoom?
I also have a room open with a link posted in the comments of my poster if that works.
https://us04web.zoom.us/j/72274118648?pwd=v9U6vtx937GGLSZ94nbKdWOIRjBjoo.1
new zoom link:
https://us04web.zoom.us/j/72274118648?pwd=v9U6vtx937GGLSZ94nbKdWOIRjBjoo.1
Feel free to talk to me from 15 30 at:
https://us04web.zoom.us/j/73350670566?pwd=ZJ5hLiUL3EiMy8GQgw9Vo53eNKMsdx.1
Very interesting approach! One question I have – given that neuronal avalanches in whole brain imaging, is whether you might be able to invert this approach to estimate the probability that a given event measured in a particular M/EEG channel does or does not come from the same avalanche as other M/EEG channels?
Hi, thank you! I understand what you mean I think, but I would not be sure how to do that. It is very likely that at the meso/microscopic scale there are multiple processess that happen simoultaneously. However, from MEG/EEG alone I would not know how to infer that. Possibily, new neuropixel probes might provide better data to test this.
On a side note, one thing that I personally find interesting is that the probability that two brain regions will be sequentially recruited by an avalanche is propotional to the intensitiy of the structural connection (i.e. the white-matter bundle connecting any two regions – https://elifesciences.org/articles/67400). Furthermore, if you consider all the active regions as belonging to the same avalanche, you will find shape collapse, power-laws etc., which also might hint at the fact that considering (at the large-scale) that all the regions would be in one coehrent ‘big’ avalanche might be a useful construct.
Thanks again for your question, and feel free to reach out to discuss further if you feel like it.
Cheers!