Neurons & Genes

Broken Neuron Network Re-wires Itself to Compensate for Lost Function

Here at Neuron News we will preach until the End of Days and beyond that it’s all about the network when it comes to fully understanding brain function. This knowledge will thereby lead to someday better understanding how to develop neuron devices that directly interconnect with the brain.

Researchers at the Max Planck Institute of Neurobiology recently reported on their observations of how versatile and amazing our neuron networks actually are, and how powerful the system really can be when trauma strikes.

After a literal tear in the retina, the research group watched as the remaining neurons, who lost their original network connections, re-wired to other neurons in the system with up to three-times the amount of brand-new interconnectivity. The network compensated for its breakdown, and re-worked itself to attempt to regain new functionality.

The observation of this sort of restructuring activity in an adult brain is extremely exciting for further research into efforts to help patients recover after serious brain injuries. Even more so, this network adaptability is key to understanding how to best design and develop cultured neuron networks in ways that will most likely and most successfully connect with a host brain.

Just throwing a plate of neurons onto a host brain is not quite enough to create a useful and functional neuron device; we must have a deep understanding of how neurons network themselves and how we might tailor the cultured devices to better link in with the brain. If this form of “hyper-networking” is a result of neurons sensing a local trauma, then we might even be able to manipulate stronger, more complex interconnections between device and brain by introducing faux “traumas” in the cultured neuron networks of implanted devices.

Let our readers know what you think by responding after reading the following articles.

“Neighbour’s aid for jobless nerve cells” :: PhysOrg.com :: September 1, 2008 :: [ READ ]

Max Planck Society Press Release – pdf [ READ ]

The Neural Connections of our Decisions

Much research into brain function looks at large-scale electrical behavior of the brain. For example, fMRI is a wonderful tool and can peer deep into our brain’s function while we are alert and making decisions that might be detected by the machine.

Although this sort of information and attempt at a broad understanding of brain activity is valuable, a pure understanding of how our complex minds truly work is still locked away at a lower level of structure. Not as low as the individual neuron itself, but at the level of the interconnectivity of enormous collections of neurons.

A single neuron is impressive, but is biologically rudimentary in function (and this is such an understatement!). A ball of 10^11 neurons is a biological mess. However, a vast, interconnected network of 10^11 neurons is really something, and it somehow produces something else truly special: our minds.

The following two articles provide a crucial reminder of the importance that a global view doesn’t quite get us to the deepest answers… and that the specific interactivity of the neuron networks themselves presents some interesting behaviors.

But, even this latter work (as you must read by following the links below) is entirely based on mathematical modeling, which is certainly an important method for creating hypothesis of how neuron networks might work in the real world. This theoretical computational approach also offers new inspirations to what to look for during actual experiments on living neural communication. It’s “just” a model, however, and not quite the real world. So, we’re still far from complete understanding.

As has already been said here on Neuron News before (and will be written about many more times because it is so critical!), the future of neurotechnology will rely on our deep understanding of the network behavior of neurons because it is the network — in particular, the structure of this network — that is the underlying physics of higher brain functioning.

To understand the network is to understand the brain. With this understanding, we will be able to develop the technology to externally connect into the brain.

“Decision Making in the Brain: Eavesdropping on Neurons” :: Scientific American :: August 5, 2008 :: [ READ ARTICLE ]

“When Neurons Fire Up: Study Sheds Light On Rhythms Of The Brain” :: ScienceDaily :: August 5, 2008 :: [ READ ARTICLE ]

“Nonperiodic Synchronization in Heterogeneous Networks of Spiking Neurons” :: The Journal of Neuroscience :: August 6, 2008, 28(32):7968-7978 :: [ READ ABSTRACT(full article text requires subscription)

Latest Success in ALS Research is Fundamental for the Future of Neurotechnology

It might not be immediately obvious how research developments in Amyotrophic Lateral Sclerosis (ALS — or, Lou Gehrig’s Disease) would be appropriate to follow here on Neuron News. However, this author has a personal family member currently dealing with the devastating disease, so we’ve been personally reviewing the progress in the field. And, with a little trivial forward thinking, there is an important connection with the advancement of neurotechnology.

Yesterday, a collaboration between Columbia and Harvard Universities announced in Science a fabulous new development that offers promise in the short-term discovery of drugs as well as longer term neuro-therapeutic technologies.

Credit: J. T. Dimos et al., Science Express

The key problem with ALS patients is that motor neurons–particularly those affecting function in breathing and swallowing–degenerate and die off for unknown reasons. So, the general idea of this research program is to develop a technique to take skins cells of a patient and convert them into stem cells, or the “universal cell” that can potentially turn itself into any other cell given just the right biochemical nudge. Now, with a vast supply of genetically appropriate stem cells that will agree with the personal biology of the patient, convert them into motor neurons and implant them into regions of the body to integrate into neural systems that have been severely degraded by the disease.

This is certainly an exciting development for nearing potential therapies for ALS, although real clinical progress is likely still many years away. If you know of anyone affected by ALS or are interested in supporting the research, please thoroughly read the articles referenced below and consider a donation to The ALS Association.

In addition, this research provides experimental evidence of a new technique developed just last Fall called induced pluripotent stem (iPS) cells. This is a very important fundamental technological advance that should guide the future of neurotechnologies.

Specifically, if neuroprosthetic devices are to be successfully integrated into the nervous system of a human being, it seems reasonable that the genetic make-up of the neurons living on the implanted device should compatible, if not identical, to the genetics of the host neurons. There might be unrealized neuro-communication factors that are influenced by genetic coding, and a fully successful device might need to be grown using neurons developed directly from the human host.

“Harvard-Columbia Team Creates Neurons from ALS Patient’s Skin Cells” :: CUMC News :: July 31, 2008 :: [ READ CUMC Press Release ]

“Stem Cell Breakthrough in ALS Research” :: ScienceNOW Daily News :: July 31, 2008 :: [ READ ]

“Stem cell technique is ‘significant advance'” :: Telegraph.co.uk :: August 1, 2008 :: [ READ ]

EmaxHealth :: [ READ SUMMARY OF MEDIA COVERAGE ]

Developing Three-Dimensional Cultured Neuron Networks

Visualize a computer chip for a moment… it’s a “flat”, 2-dimensional piece of electronics that does some fancy electron dance somewhere within the green-toned plastic. Now, visualize what a neurological computer chip might look like… how about we start with the same flat, green-toned plastic electrical processing unit and toss on a bunch of living neural cells scrambled all over the surface.

This sort of technological device–which is not entirely science fiction–is this idea of a two-dimensional, cultured neuron network interfaced with a microfabricated electrical circuit. This system in no way resembles the network structuring seen in the human brain, so the first immediate question would be to ask why would this living, 2-D neuron network successfully electrically interface with the brain?

Well, that is a good question… but this 2-D world was (and still is) a reasonable starting point for developing the technology. In fact, because the 2-D world is still an important system for developing merged devices composed of electrical circuits and living networked neurons, developing an understanding of the fundamental neuron network function–in two dimensions–is still critical and valuable for neurotechnological research.

But, the brain is still in three dimensions, so advancing the technology to grow cultured neuron networks in controlled ways in 3-D is quite exciting. With a current published article inNature Methods, researchers from the University of California Berkeley and Lawrence Berkeley National Lab have begun some initial work on controlling the cultured growth of neurons in three dimensions along the bumps of blobs of colloidal crystals.

Micron-sized colloidal particles (i.e., really tiny balls made of clear plastic) are interesting for patterning neuron networks, because there has been a great deal of work on learning how to manipulate these objects using focused laser light called optical tweezers. If the wavelength of the laser beam is selected appropriately, then the living neurons will not absorb the wavelength and heat up and die. So, additional modifications to the underlying colloidal matrix could be made to the system while the neurons were growing and interconnecting along the 3-D lattice.

“Colloidal crystals make better neural networks” :: Ars Technica :: July 28, 2008 :: [ READ ]

“Colloid-guided assembly of oriented 3D neuronal networks” :: Nature Methods :: published online July 20, 2008 :: (doi:10.1038/nmeth.1236) [ READ ABSTRACT ]

Billions of Transistors Don’t Match Billions of Neurons

Q: What do you get when you interconnect billions and billions of transistors?

A: A whole lot of ON/OFF switches.

The brain is a ridiculously complicated network of electrochemically active cells (a.k.a. neurons), which are individually influenced by a large number of greatly complicated chemical machines (a.k.a. synapses), which are in turn individually activated by more particular chemicals and hormones, and even further influenced by microscopic structures which are coupled at the quantum level.

This is not the hierarchy of your typical computing machine. Technologists have long anticipated the future of vast computer networks–built upon the electrical transistor–that pass some unknown critical point of interconnections and become “conscious”. Welcome Hal.

Neurobiologists have long been frustrated by this expectation because the level of complexity of the brain as a whole and the level of complexity of its individual parts no where matches that of the computer chip. In fact, this expectation is still so unreasonable because of the remaining immense lack of understanding of how the brain works as a sum of all of its parts to generate the emergent behavior we experience every moment of our lives.

Lee Gomes of WSJ.com provides us with a nice reminder of how far we really still have to go to fully understand the brain… but, it is also a wonderful stimulus to excite us to push further on in the quest to understanding the mass in our skull… and understanding the nature of our existence.

“Linking Brains, Computers” :: Wall Street Journal.com:: July 9, 2008 :: [ READ ]

NIH Serious about Advances in Understanding the Brain

The NIH is certainly serious about making real things happen in neurotechnologies. Setting up large awards for significant steps forward in science and technology has been a tried and true method of encouraging the human race to make a leap from Lindberg to the X Prize. Here is another government-funded opportunity aimed at developing plans for the next-generation technologies for non-invasive imaging of brain function. Mapping detailed  live neuron interactions without the need for drilling through the skull is a holy-grail for reaching a deeper understanding of complete brain function, and it’s time to get real serious about making real progress with new technology.

[Read the entire Request for Information]

“NIH requests input on non-invasive brain imaging techniques” BioOptics World :: June 24,  2008 :: [READ]

Last updated October 26, 2021