Our plastic brains
The brain’s reparative plasticity is especially marked in young people, such as this boy who had one-sixth of his brain removed when he was just six years old:
What happened to Collins is a remarkable example of neuroplasticity: the ability of the brain to reorganize, create new connections, and even heal itself after injury. Neuroplasticity allows the brain to strengthen or even recreate connections between brain cells—the pathways that help us learn a foreign language, for instance, or how to ride a bike.
The fact that the brain has a malleable capacity to change itself isn’t new. What’s less understood is how exactly the brain does it. That’s where Behrmann’s study of Collins comes in. Her research question is twofold: To what extent can the remaining structures of Collins’ brain take over the functions of the part of his brain that was removed? And can science describe how the brain carries out these changes, all the way down to the cellular level?
Collins’ brain seems to have rewired and is working just fine. Scientists have been studying him (as well as a few other children in similar situations) ever since his surgery. He is twelve now:
Just how the brain accomplishes this feat remains a central question. By analyzing brain scans using a neuroimaging technique known as diffusion tensor imaging, which shows how water travels along the brain’s white-matter tracts, Behrmann has found initial glimmerings that the white matter of the brain?—?the electrical wiring that underlines communication between multiple neurological regions?—?actually changes. Areas of the brain that weren’t connected before create new links, an example of neuroplasticity in action that may preserve brain functionality. But scientists still don’t know what triggers the cells of the white matter to behave in this way.
The body also finds replacement paths for blood flow, for example, when one is compromised somehow. Or it did when I last studied biology 50 years ago. IOW, if you lose arterial flow for some reason, smaller patterns of blood flow step in to take up the needed compromised arterial function.
Other commenters can certainly explain this better than I.
Our bodies and mentality are both incredibly resilient and exceedingly fragile.
Collateral circulation works when there is time to accommodate, I once had a patient who had one carotid artery open, of the four arteries that normally supply the brain. As long as it is slowly progressive, the body can accommodate a lot.
I had a book, I don’t know where it is now, about a boy in Argentina who had one cerebral cortex removed, I think it was a seizure disorder. Anyway he compensated quite well. There were a number of experiments done back in the 1950s with men who, through war wounds, had had the corpus callosum divided, disconnecting the two hemispheres,.
The researchers were able to communicate separately to the two hemispheres although only the dominant hemisphere was conscious. I can’t find the source now. I think it was in Scientific American back before it got political,.
Protozoa are a diverse family of single-cell animal-like organisms.
There are predator and prey species, both of whom exhibit the typical, familiar behaviors of their mammalian counterparts. It’s eerie, watching them under a microscope. They hunt, they entrap, they evade, and hide … and it all looks very much like wolves & deer.
These are behaviors that we credit (entirely) to the brain-network, yet evolution produced sophisticated behavior, before the brain, or even a neuron.
Whether there is still something going on in advanced animals today, that does not depend or arise wholey from the brain-structures, we don’t know (and it’s not a ‘proper’ question … ‘mysticism’), but since early in evolution, the lack of a brain has not been an obstacle to advanced behaviors.
But it is too common that people with brain-damage are not otherwise as damaged as we would certainly expect…
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The real driver behind neural plasticity, is Christopher Reeves.
Flat worms can be trained to negotiate a maze . Then you feed that flatworm to another one. The second one now knows how to negotiate the maze,
But no one eat Dr Mike K!
We don’t work like flatworms.
You have to do the study & hard work as a human to be a Dr!
😉
Mike K:
Your story of the Argentine boy is not surprising — do you know any Argentines?
Read this a number of years ago and was tremendously impressed.
(paragraphing added to this blurb)
Warning: this book includes anecdotes about patients; one presumes they gave consent, but Doidge is making money off of their stories. 😉
Trivia: Doidge wrote a foreword for Peterson’s “Twelve Rules” – they seem to have become friends due to shared interests and academic convergence.
http://www.normandoidge.com/?page_id=1259
“THE BRAIN CAN CHANGE ITSELF.
It is a plastic, living organ that can actually change its own structure and function, even into old age. Arguably the most important breakthrough in neuroscience since scientists first sketched out the brain’s basic anatomy, this revolutionary discovery, called neuroplasticity, promises to overthrow the centuries-old notion that the brain is fixed and unchanging.
The brain is not, as was thought, like a machine, or “hardwired” like a computer. Neuroplasticity not only gives hope to those with mental limitations, or what was thought to be incurable brain damage, but expands our understanding of the healthy brain and the resilience of human nature.
Norman Doidge, MD, a psychiatrist and researcher, set out to investigate neuroplasticity and met both the brilliant scientists championing it and the people whose lives they’ve transformed. The result is this book, a riveting collection of case histories detailing the astonishing progress of people whose conditions had long been dismissed as hopeless.
We see a woman born with half a brain that rewired itself to work as a whole, a woman labeled retarded who cured her deficits with brain exercises and now cures those of others, blind people learning to see, learning disorders cured, IQs raised, aging brains rejuvenated, painful phantom limbs erased, stroke patients recovering their faculties, children with cerebral palsy learning to move more gracefully, entrenched depression and anxiety disappearing, and lifelong character traits altered.
Doidge takes us into terrain that might seem fantastic. We learn that our thoughts can switch our genes on and off, altering our brain anatomy. Scientists have developed machines that can follow these physical changes in order to read people’s thoughts, allowing the paralyzed to control computers and electronics just by thinking.
We learn how people of average intelligence can, with brain exercises, improve their cognition and perception in order to become savant calculators, develop muscle strength, or learn to play a musical instrument, simply by imagining doing so.
Using personal stories from the heart of this neuroplasticity revolution, Dr. Doidge explores the profound implications of the changing brain for understanding the mysteries of love, sexual attraction, taste, culture and education in an immensely moving, inspiring book that will permanently alter the way we look at human possibility and human nature.”
Question: Why does the plastic brain not reroute around Alzheimer? I ask the question because that is something I never want, give me a massive heart attack so I can die like my father in an instance at 82.
Watch it, proles and primitives!
Gays and Trans are Born That Way so keep your hateful patriarchical colonialist science to yourselves!
We will wrap our agenda in the mantle of science when it suits us, and discard/denounce science when it contradicts The Narrative.
Mike K. See The Wormrunners’ Digest. That platyhelminthes–showing off here–thing was a big deal. For a while. Then it turned out the grad students hadn’t been cleaning the Y maze trays and the second order of flatworms were following the slime trail of their unfortunate predecessors.
But, for a while at least, the science was settled.
I heard, back in the day, that in WW I the medical people had started to get a handle on sepisis, which previously had killed many soldiers whose wounds were survivable from a medical or anatomical standpoint.
So they had live guys with horrible head wounds to study over the years.
Plus a lot of other guys who might have preferred to be dead. The French built resorts for soldiers so hideously mutilated that they wouldn’t come out in public.
Planaria – flatworm – Memory Tricks
Planaria also demonstrate the point I made earlier, using Protozoa, that the basis of behaviors normally thought to arise from & require a brain, is in some cases independent of an organized neural body.
The key goal of 1950s-’60s memory-experiments using planaria (by James McConnell) was to demonstrate a transferable, ‘communicable’ memory “particle” – which he termed RNA Memory. While reusing the same unwashed dishes seems like an obvious & easily-corrected mistake, this is now the accepted explanation for his now-believed spurious results.
https://en.wikipedia.org/wiki/Planarian#Biochemical_memory_experiments
Less subject to housekeeping lapses have been experiments that cut trained flatworms into pieces (some lacking the head & ganglion-‘brain’), from which whole individuals regenerate (Actually, planaria are more important as a Regeneration Model … and we are now identifying the genes responsible for this.), which then at least ‘somewhat’ retain earlier training.
Shomrat T, Levin M (October 2013). “An automated training paradigm reveals long-term memory in planarians and its persistence through head regeneration“. The Journal of Experimental Biology. 216 (Pt 20): 3799–810. doi:10.1242/jeb.087809. PMID 23821717. ibid
There is also a small “Memory RNA” Wikipedia article which contains several useful citations; especially:
Duhaime-Ross, Arielle (17 September 2013). “Flatworms Recall Familiar Environs, Even after Losing Their Heads“. Scientific American.
http://www.scientificamerican.com/article/flatworms-recall-familiar-environs-even-after-losing-their-heads/
https://en.wikipedia.org/wiki/Memory_RNA
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There is a long-standing ‘notion’ that there is ‘something going on’ to which we are not yet privy, to explain the retention of memory, and more broadly, the inheritance ‘instinct’ & adaptive/learning-potential. Especially, newly-discovered molecules or substructures of the cell are often credited with an unrecognized role. Some workers appear to have brought their ‘conviction’ to the lab-bench … but that does not entirely dismiss the observed phenomena.
“But, for a while at least, the science was settled.”
Hahaha.
A snatch from Wiki on diffusion-weighted MRI:
Diffusion imaging is an MRI method that produces in vivo magnetic resonance images of biological tissues sensitized with the local characteristics of molecular diffusion, generally water (but other moieties can also be investigated using MR spectroscopic approaches).[9] MRI can be made sensitive to the motion of molecules. Regular MRI acquisition utilizes the behaviour of protons in water to generate contrast between clinically relevant features of a particular subject. The versatile nature of MRI is due to this capability of producing contrast related to the structure of tissues at microscopic level. In a typical {\displaystyle T_{1}} T_{1}-weighted image, water molecules in a sample are excited with the imposition of a strong magnetic field. This causes many of the protons in water molecules to precess simultaneously, producing signals in MRI. In {\displaystyle T_{2}} T_{2}-weighted images, contrast is produced by measuring the loss of coherence or synchrony between the water protons. When water is in an environment where it can freely tumble, relaxation tends to take longer. In certain clinical situations, this can generate contrast between an area of pathology and the surrounding healthy tissue.
To sensitize MRI images to diffusion, instead of a homogeneous magnetic field, the homogeneity is varied linearly by a pulsed field gradient,
Got it?
Dr. Mike K:
A relatively small number of cerebral hemispherectomies were done in the 1950s as desperation therapy for glioblastomas (for the rest of you, the malign brain tumor that killed McCain and the ‘Lion of the Senate’). Yielded the expected profound neuro deficits (hemiplegia, etc,) but did not, repeat not, extend survival over less radical resection. So standard of care became whole brain irradiation, which added some weeks (10-12) to survival over partial resection alone, but at the cost of creating a fair # of human cabbages. Fortunately CT, then MRI came along a generation later, facilitating much more precise resection, but now even with today’s best triple therapy (surg, irradiation, chemo) median survival has been extended only from ~30 weeks to ~65 weeks. Wow! Median survival has doubled! But it is almost universally fatal in a still rather short time.
But, for a while at least, the science was settled.
I suspected something like that. Great story, though.
Cicero, the cases I was referring to were divided corpus callosum, not hemispherectomy. They were done for post trauma seizures. The Argentine boy case was a child of about 5.
He was 3.
The biggest problem with glioblastoma, as I understand it, is that it is multifocal.
Multifocality of GBMs is about 12%.
Doctors don’t like me telling them that every 10 years, their collection of knowledge is made half obsolete.
The Authorities don’t like hearing that either.
Here’s a hint, the brain is not the seat of consciousness. There are 3 centers in the human body that can be considered as a processing center. The brain is much closer to a wifi receiver and a radio.
Some years ago, some Doctor Class here was replying to my comment about Chinese medicine and research on the microbiome. That wasn’t in the medical textbooks apparently for Doctor Class here so… this just sounded like mumbo jumbo chin chin sounds to the Doctor Class Authority.
Meanwhile, in these days, supermarkets have probiotics and doctors are telling their families to use probiotics to… aid their destroyed gut bacteria in the microbiome.
See how you humans are ridiculous over the years?
More sciency stuff from a quack “My friend the witch doctor he told me what to say…”
The science is settled for you om, based on your religious and dogma.