"Researchers have created the largest atlas of human brain cells so far, revealing more than 3,000 cell types — many of which are new to science. The work, published in a package of 21 papers today in Science, Science Advances and Science Translational Medicine, will aid the study of diseases, cognition and what makes us human, among other things, say the authors. The enormous cell atlas offers a detailed snapshot of the most complex known organ. “It’s highly significant,” says Anthony Hannan, a neuroscientist at the Florey Institute of Neuroscience and Mental Health in Melbourne, Australia. Researchers have previously mapped the human brain using techniques such as magnetic resonance imaging, but this is the first atlas of the whole human brain at the single-cell level, showing its intricate molecular interactions, adds Hannan. “These types of atlases really are laying the groundwork for a much better understanding of the human brain.”" https://www.nature.com/articles/d41586-023-03192-2
It's a common trope to bemoan the lack of progress out of biomedicine, aka scientific medicine, in mental health and psychiatry. But really this isn't especially surprising when a field is still in its infancy, and barely has a basic catalogue of what the organ is made of. Psychiatry is barely where astronomy was in the 1930's, when they still couldn't even be sure if planets existed elsewhere. Whereas psychiatry is basically stuck in a stage like the 'faces' on Mars seen on low-resolution telescopes, inventing civilizations out of mere shadows. Personally I would bet on biomedicine to deliver all the results, and the obsolete biopsychosocial to deliver exactly nothing at all. After all, one approach is scientific, the other is judgmental and mostly bigotry. It certainly doesn't help that parts of psychiatry, and somehow neurology, are stuck at weird phases insisting that sick people shouldn't feel bad about being sick because symptoms are just signals that can be ignored, that symptoms are just worries about diseases expressing themselves. Or whatever the hell is it that they mean, I can, make any sense out of it. Although it's kind of weird to read comments such as expressing surprise that the brainstem is more complicated than they thought. Where did they even get the idea that it was somehow simple, or that they understood it well enough to pass this judgment? Now this is science. Science is awesome and it begins at knowing what is there, until then all you have is either speculation or tales. They really have to let go of the damn fairy tales.
But....they don't day how large this map is. Given practically all things related to size are in Wales's, Europe's, Brazil's or more recently giraffes, just how big is this largest map of the brain?
In my recent scan of ScienceDaily, I found several articles on mapping of the human brain: https://www.sciencedaily.com/releases/2023/10/231012161736.htm "In a large, multi-institutional effort researchers have analyzed more than a million human brain cells and revealed links between specific types of cells and various common neuropsychiatric disorders." https://www.sciencedaily.com/releases/2023/10/231012161739.htm "Scientists analyzed more than half a million brain cells from three human brains to identify previously unknown brain cell subtypes. Their research paves the way for understanding how certain brain cell types go awry in brain disorders and diseases." https://www.sciencedaily.com/releases/2023/10/231012161838.htm "By combining non-invasive imaging techniques, investigators have created a comprehensive cellular atlas of a region of the human brain known as Broca's area." So, there is biomedical progress in understanding mental/neurological disorders. I expect we'll get actual diagnostic tests and treatments from this type of research, while the psychiatrists continue to blame teddybear-separation for disorders, and offer "thinking yourself well" as treatments. Totally aside, another article had: "The researchers found that people carrying three so-called Neanderthal variants in the gene SCN9A, which is implicated in sensory neurons, are more sensitive to pain from skin pricking after prior exposure to mustard oil." Now I'm stuck with an image of a lab where "In room 1, we rub people with mustard and then jab them with needles. In room 2, we rub them with pineapple juice and hit them with hammers. So Monty-Pythonesque." The article did say "measured the pain thresholds of 1,963 people from Colombia in response to a range of stimuli.", so it's probably valid research, but I'm still stuck with weird imagery.
The real problem is that nobody knows how each cell interprets and responds to information coming in to its dendrites. It is a bit like knowing all the cable connections in a computer but nothing about computer programming because nothing is known about how the silicon chips work. Knowing all the cable connections may make it easier to work out how the chips work but it does not get you very far in knowing how the computer adds 2 and 2 or plays chess.
This looks like a massive effort and achievement no doubt. There's a lot of papers that use an array of different techniques but for the most part it looks to be a single cell transcriptomic cell type atlas. This is a great resource that will tell you what cells there are and what the cells look like in terms of their gene expression (which genes are switched on or off in each cell). It looks like there's also work on their morphology from various studies looking at neurons with microscopy and so on (morphology = what the cells actually look like, their shape). There are some studies that do things like spatial transcriptomics where they basically take a slice of particular small region of the brain and throw lots of different gene probes onto it which they can light up fluorescently, and thus gives you a sense of which cells are approximately located where. However from what I can see there isn't much in the way of connectomics, that is, how the cells actually connect to each other - which you would want to know as a starter to see how the information could flow through the brain and calculations could be made. There may be some work on this but I think it would be in highly targeted experiments and not brain wide. It doesn't seem like we know the cable 'connections' even, but maybe it's like tearing all the cables apart from each other and describing each in great detail. Doesn't tell you how it all works together - but is still valuable because if you know you've seen a certain cable in a well studied context or that contains a gene known to be relevant to disease - it gives clues about how it might be relevant here. (oh analogy falls apart when I talk about what gene is inside of a cable but you get the idea!)
Brain Atlas Paves the Way for New Understanding of How the Brain Functions "When NIH launched The BRAIN Initiative® a decade ago, one of many ambitious goals was to develop innovative technologies for profiling single cells to create an open-access reference atlas cataloguing the human brain’s many parts. The ultimate goal wasn’t to produce a single, static reference map, but rather to capture a dynamic view of how the brain’s many cells of varied types are wired to work together in the healthy brain and how this picture may shift in those with neurological and mental health disorders. So I’m now thrilled to report the publication of an impressive collection of work from hundreds of scientists in the BRAIN Initiative Cell Census Network (BICCN), detailed in more than 20 papers in Science, Science Advances, and Science Translational Medicine.1 Among many revelations, this unprecedented, international effort has characterized more than 3,000 human brain cell types. To put this into some perspective, consider that the human lung contains 61 cell types.2 The work has also begun to uncover normal variation in the brains of individual people, some of the features that distinguish various disease states, and distinctions among key parts of the human brain and those of our closely related primate cousins." https://directorsblog.nih.gov/2023/...new-understanding-of-how-the-brain-functions/
