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The Future of the Most Important Human Brain
mattnyc99 writes "About a year ago, we watched live as neuroanatomist Jacopo Annese sliced the brain of Memento-style patient Henry Molaison (aka H.M.) into 2,401 pieces. Since even before then, writer Luke Dittrich — whose grandfather happened to be the surgeon to accidentally slice open the H.M. skull in the first place — has been tracking Annese and a new revolution in brain science. From the article in Esquire: 'If Korbinian Brodmann created the mind's Rand McNally, Jacopo Annese is creating its Google Maps. ... With his Brain Observatory, Annese is setting out to create not the world's largest but the world's most useful collection of brains. ... For the first time, we'll be able to meaningfully and easily compare large numbers of brains, perhaps finally understanding why one brain might be less empathetic or better at calculus or likelier to develop Alzheimer's than another. The Brain Observatory promises to revolutionize our understanding of how these three-pound hunks of tissue inside our skulls do what they do, which means, of course, that it promises to revolutionize our understanding of ourselves.'"
While I have no wish to demean their efforts, this approach still seems somewhat brutal to me. I'm no neurologist, but isn't this still a rather macro-level view of things, with the cutting process still causing damage to the fine structures they want to study?
It seems likely to me that future scientists will look back at this in not too long with stifled laugher and perhaps a little shock at the approach.
The same applies to the dissection of other organs as well. For instance, any dissection of the heart is inherently biased towards the cutting planes defined by the dissector (source). The true arrangement of muscle fibers in the left ventricle of the heart (more precisely the existence of sheet structure) is still a subject of hot debate because of this. Obviously, one might think that by now, we should be able to just pick an organ and throw it into the best relevant imaging scanner (CT, MRI, PET, etc.). The truth is, there is still anatomical information that even state-of-the-art medical imaging modalities cannot reliably reveal.
As an example, consider DT-MRI that measures the diffusion of water molecules along the tissue fibers in an organ. The discretization in the data is such that only the local average orientation of the diffusion of water is known at any given location. To obtain more useful anatomical information, the full fiber pathway in a region needs to be reconstructed, a task called fiber tractography. Different computational methods based on different anatomical assumptions lead to results that are often contradictory (as is the case in the heart models described in the article cited above) and since there is no ground truth (remember that the dissection is biased), we currently hit a dead-end.
Hopefully, as more dissections (like this one) are performed and the data is made available publicly, we will eventually be able to faithfully reconcile pieces of what we observe in medical conditions, in medical scanners, and on the dissection table.