Tag Archives: Blood-Brain Barrier

Wow, this is interesting

Scientists Find Vessels That Connect Immune System And Brain. June 3, 2015 | by Stephen Luntz. IFL Science.

http://www.iflscience.com/brain/vessels-found-connect-immune-system-and-brain

Structural and functional features of central nervous system lymphatic vessels

Antoine Louveau, Igor Smirnov, Timothy J. Keyes, Jacob D. Eccles, Sherin J. Rouhani, J. David Peske, Noel C. Derecki, David Castle, James W. Mandell, Kevin S. Lee, Tajie H. Harris & Jonathan Kipnis
Nature (2015) doi:10.1038/nature14432
Received 30 October 2014 Accepted 20 March 2015 Published online 01 June 2015

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14432.html

I find this most interesting for a number of reasons. Firstly, the discovery showing that the human brain has functional lymphatic vessels connecting the brain with the immune system adds to a growing collection of evidence that the immune system plays important roles within the brain, which is an apparent partial violation of the long-held concept of the “blood-brain barrier” (as was described in a dated and inadequate chapter by Dr Karl in his 2013 pop science book Game of Knowns). In 2012 I was apparently the first person in the world, at this blog, to publish the ideas that high or low levels of the “component” immune chemicals at various points in development could be the cause of conditions of the brain such as developmental synaesthesia and Benson’s syndrome or PCA. My ideas were inspired by the very exciting research in areas such as microglia, complement, synaptic pruning and MHC1 molecules.

Another reason why this new discovery linking the central nervous system with the lymphatic and immune systems by researchers from the University of Virginia is so exciting is the fact that it is an unexpected discovery, as one might have thought that human anatomy would have already been thoroughly researched and discovered through the history of medical science to date, but then again, surprising new discoveries in human anatomy have not been unknown in recent years, with discoveries of new features in the human eye, knee and clitoris, the rediscovery last year of a major white matter tract (the vertical occipital fasciculus) at the rear of the brain that could play a central role in skills such as reading, and a new shape of neuron discovered in mouse brains. These new discoveries are exciting and also rather unsettling; exciting because it appears that important new discoveries in human neuroscience and anatomy are still possible, and unsettling because genuinely surprising new discoveries in science seem to indicate that science is not a steady accumulation of knowledge and a path of upward progress, as many believe. This may or may not be surprising to you, depending on which theory in the philosophy of science you favour. I think the discoveries of the VOF and the collection of discoveries about the roles and anatomy of the immune system in the human brain could be interpreted as evidence showing how incorrect ideas in science can become widely-accepted and widely-taught and could also have delayed the progress of new discoveries in neuroscience. How much further might we have come by now in our understanding of the human brain and mind if not for the popularity of the idea that the human brain is quarantined from the immune system? Which other influential ideas about the human brain are holding us back from a clearer understanding of the brain’s workings and diseases?

There’s a back-story to my theory

I can show data dating back to the year 2000 that supports my theory that low levels of complement proteins, which are a part of the human immune system, specifically C3, C4 and most likely C1q, are the biological cause of the development of inherited synaesthesia (at least in some cases). Before I had thought of the idea of a link between the immune system and synaesthesia I had, at the blog, published a theory that synaesthesia is in some way the neurological opposite of a variety of dementia named Benson’s syndrome (aka PCA, posterior cortical atrophy), based on my observations and reading. I had speculated that there could be some “magical chemical” that regulated the brain in some way and that oppositely extreme levels of this magical chemical could be the biological basis of both synaesthesia and Benson’s syndrome. Back in 2012 I read a small article in New Scientist magazine that blew my mind, because it appeared that it gave me some major clues about what that magical chemical could be. The article was about the exciting work of Dr Beth Stevens on microglial pruning in the brain and the immune system’s complement proteins. The term “pruning” was familiar to me from all of my reading about synaesthesia, which is a fun heritable brain-based phenomenon which I share with some of my first-degree relatives, along with specific gifts in literacy skills. The term “complement” in the context of the immune system, and the individual names of complement proteins were also familiar to me.

Being a super-recognizer, I’m pretty good at recognizing patterns, and I recognized that all these elements of information fitted together into an important and original multi-faceted theory. I was so excited that I published a brief outline of my theory at this blog in 2012. In 2013 I was shocked to discover that a prominent synaesthesia researcher and her co-author had published a theoretical journal paper titled “The immune hypothesis of synesthesia” which even included speculation that the “complement system” could be the element of the immune system responsible for the development of synaesthesia. I found no credit given in that paper to me or my blog. As I had published my theory first I believe I should have been fully acknowledged. I never thought that this could have been a case of two separate parties thinking of the same idea independently. I read their paper through and I looked into the educational and research background of both authors and their previous publications and found no study or writing about the immune system and no indication or explanation of why they might have suddenly had their own insight linking synaesthesia with some of the many elements of the incredibly complex immune system that only an immunologist would find interesting. 

This Easter I’d like to pose the question; can Simner and Carmichael offer data dating back to the year 2000 as the basis of their published version of “the immune hypothesis of synesthesia”? I can, and I would be willing to share my data with serious medical researchers.

A while ago I was sorting through some piles of old papers that I had stowed away years ago without sorting through them. These things happen during a busy family life. These piles had been sitting around for years, some of it photocopies of articles from New Scientist magazine that had struck me as interesting but which I hadn’t always had the time to read through properly. I was amused to find that I had stowed away an article from the March 1st 2008 issue titled “Thought control” by Bijal Trivedi. It was all about exciting research by the likes of Carla Shatz, Ben Barres, Simon John, Staffan Cullheim, Eliezer Masliah, Robert Terry and Lisa Boulanger about synapse loss in dementia and the interesting things that elements of the immune system appeared to be doing in the brain, contrary to the received wisdom that there is a thing called the blood-brain barrier that keeps the immune system out of the brain. I’m not sure whether or not I had read the article back then, but I can understand why it had sparked my interest. Back then it wasn’t enough of a spark to give me the idea of a link between the immune system and synaesthesia, because back then I hadn’t even heard of the terms “super-recognizer” or “Benson’s syndrome”, in fact the concept and the term of “super-recognizer” hadn’t yet been published. Back then I had not the slightest inkling that I had better than average ability in face recognition, so I hadn’t started thinking about whether it was more than a coincidence that I was both a synaesthete and a super, and which parts of the brain might be atypical in both. I hadn’t read the human interest story in The West about a Perth citizen who had been diagnosed with Benson’s, and felt curious about how the description of that type of dementia sounded like the opposite of skills that were superior or associated with synaesthesia in myself and kin. I must have forgotten about the content of the 2008 New Scientist article, if I had ever read it at all, because it would have been the ribbon which I could have used to wrap up my package of ideas neatly. Curiosity can be rewarded, even if it takes a couple of coins before the penny drops.

 

The two most exciting science magazine articles of 2013 (far as I’m concerned)

The most exciting blogging moment of 2013 for me was probably when I discovered that my idea about linking synaesthesia with the immune system, and idea which I published in the winter of 2012 at the blog, had been recycled without my permission in a paper that was published in October 2013 in a journal that is apparently peer reviewed and all that fancy stuff. Of course, the big excitement of 2012 was thinking of this idea along with a suite of more important and related ideas, and the excitement continued this year as I read more about the work of researchers such as Carla Shatz, Ben Barres, Beth Stevens and Marie-Eve Tremblay who are busy pushing back the boundaries of human knowledge about the complex relationship between elements of the immune system and elements of the brain. It’s a wide open and potentially very important new area of scientific discovery, and below are the details of some  items that you can read if you wish to find out what the excitement is about. Have an exciting new year.

Miller, Kenneth Brain benders. Discover. October 2013. p. 30-37.  http://discovermagazine.com/2013/oct/12-brain-benders#.UsL_B_QW18E  (disregard the guff in this article about autism and schizophrenia)

Costandi, Moheb The mind minders. New Scientist. Issue 2938 October 12th 2013. p. 45-47.  http://www.newscientist.com/article/mg22029381.000-the-mind-minders-meet-our-brains-maintenance-workers.html

One thing in the world of popular science writing that hasn’t been so inspiring and exciting in 2013 is the famous Dr Karl Kruszelnicki’s latest pop science book on the 2013 Christmas gift book market, titled Game of Knowns. The book has a chapter in it about the blood-brain barrier. The concept of a blood-brain barrier is an established and accepted idea in medicine, but I think that the new area of research about the varied and important roles in brain development and brain maintenance of cells and chemicals that were previously thought to be limited to playing roles in the immune system are very important exceptions to the old notion that the brain is normally quarantined from the immune system by the blood-brain barrier. I’ve had a quick look at Dr Karl’s new book, and it appears to me that the chapter about the blood-brain barrier fails to mention the role of these immune cells and chemicals in the brain, things such as microglia, MHC1 and complement system proteins. It appears to me that the chapter in Dr Karl’s book is dated and seriously incomplete, and missing some exciting material. Even for a populariser of science, I expect more.