Rebuilding a Damaged Brain and More

After strokes and other types of brain damage, entire areas of brain can die and be replaced by fluid filled cavities or depressions. Scientists at Kings College London are experimenting with a biodegradable polymer matrix that may someday re-build the damaged brain after strokes, abscesses, and other types of brain damage.

Scientists say that the key to the advance, published today in the journal Biomaterials, is the use of a biodegradable polymer called PLGA, which ensures that the stem cells remain in the area of stroke damage and establish connections with surrounding brain tissue. By reducing the number of stray stem cells, the system is likely to be safer as well as more effective than other methods, the researchers add.

...The researchers injected particles of the PLGA polymer loaded with neural stem cells directly into the stroke cavities. Once inside the brain, the particles link up to form complex scaffolds. Modo's team used MRI scans to pinpoint where the stem-cell injections were needed and to monitor the development of new brain tissue. "Over a few days we can see cells migrating along the scaffold particles and forming a primitive brain tissue that interacts with the host brain," says Modo. "Gradually, the particles biodegrade, leaving more gaps and conduits for tissue, fibers, and blood vessels to move into." The next step, he says, will be to add the growth factor VEGF, which should encourage blood vessels to enter the new tissue and speed its development into mature tissue.

...The key to the advance was the ability of the new polymer to encourage the growth and differentiation of the neural stem cells at three different scales, says Modo's colleague Kevin Shakesheff, a tissue engineer at Nottingham University. "At the large scale, it enables the void formed by the injury to get new blood vessels very quickly, which is vital if the new tissue is to survive. At the cellular level, the scaffold surface allows stem-cell receptors to attach to it. And at the molecular level, it will allow cells to mix with the right growth factors." _TechnologyReview

Another fascinating area of brain research involves the use of ultra-short electrical pulses to affect nanopores in the nuclear membranes of neurons, while leaving the nanopores of the cell membrane intact. This specificity appears to have interesting effects on the behaviour of neurons individually and as a group.

When an electric field is applied to a cell, a charge starts to build up on the cell membranes. After a few microseconds, the charge is so high that holes (or "pores") start to form in the cell wall, an effect called electroporation. This allows material (in particular calcium ions) to pass through, affecting the function of the cell. With shorter pulses there is not enough time to affect the cell. But electroporation can affect the structures within the cell such as the nucleus, known as organelles.

"Because the organelles are much smaller than the cell itself... they reach their maximum charge much more quickly," Center founder Karl H. Schoenbach explains in an article. " Ending the pulse after the organelles are charged up, within a few hundred nanoseconds but before large pores appear in the cell’s own membrane, lets you focus the electric field’s effects on the organelles, such as the nucleus, while leaving the cell membrane relatively untouched. That, in turn, lets you do the complex and varied things medical science is interested in, such as killing tumor cells or triggering an immune system response."

So on the one hand ultra-short pulses can be used to selectively destroy cancerous cells. But they can also produce much more effective stunning effects.

A paper from the Center on Neuromuscular disruption with ultrashort electrical pulses compares 450-nanosecond pulses with multi-microsecond Taser pulses and found that the shorter pulses were more effective for suppressing voluntary movement, and used less energy. Another study found that even shorter, 60-nanosecond pulses could stun rats.

But the most significant is a paper which found that it was possible to incapacitate cells for a prolonged period -- "our study provides experimental evidence that even a single 60-ns pulse at 12 kV/cm can cause a profound and long-lasting (minutes) reduction of the cell membrane resistance (Rm), accompanied by the loss of the membrane potential." _Wired

I understand if a readers eyes fog up while reading fine print in italics dealing with scientific topics, particularly late at night when they really should be in bed asleep. But it might be worth one's time to contemplate the implications of research on ultra-short electrical pulses on neurons individually and in aggregate.

I will come back to both of these topics in the future.

Savantic Latency: Mind the Current

Are you a latent savant, with hidden mental powers waiting only for the proper trigger, to reveal themselves? Perhaps. A recent posting by commenter Mike led to this provocative NYT article from 2003 about the work of esteemed neuroscientist Allan W. Snyder:

If Snyder's suspicions are correct, in fact, and savants have not more brainpower than the rest of us, but less, then it's even possible that everybody starts out life as a savant. Look, for example, at the ease with which children master complex languages -- a mysterious skill that seems to shut off automatically around the age of 12. ''What we're doing is counterintuitive,'' Snyder tells me. ''We're saying that all these genius skills are easy, they're natural. Our brain does them naturally. Like walking. Do you know how difficult walking is? It's much more difficult than drawing!''

...Snyder's theories are bolstered by the documented cases in which sudden brain damage has produced savant abilities almost overnight. He cites the case of Orlando Serrell, a 10-year-old street kid who was hit on the head and immediately began doing calendrical calculations of baffling complexity. Snyder argues that we all have Serrell's powers. ''We remember virtually everything, but we recall very little,'' Snyder explains. ''Now isn't that strange? Everything is in there'' -- he taps the side of his head. ''Buried deep in all our brains are phenomenal abilities, which we lose for some reason as we develop into 'normal' conceptual creatures. But what if we could reawaken them?''____Source

Snyder, who has been publishing in the scientific literature for several decades, currently experiments with transcranial electromagnetic stimulation to bring out latent abilities mental.

The researchers think that by temporarily inhibiting activity in the left anterior temporal cortex, the TMS allowed the brain’s number estimator to act on raw sensory data, without it having already been automatically grouped together into patterns or shapes. In other words, they believe it caused the 'normal' brain to function more like an autistic 'savant' brain.___Source

Some forms of electromagnetic stimulation enhance the function of the stimulated portion of brain, and other forms of EMS suppress the function of the stimulated brain. Such a tool can function in an analogous way to a reversible "knock-out gene" in genetics research. By removing particular "instruments from the brain's symphony", we can glimpse the workings of a differently arranged brain.

It is not really a matter of whether savants have more or less brainpower than the rest of us. It is a matter of how the brain is being used. As people gain experience in life, they use forms of "mental shorthand" to speed repetitive mental functions. We do not actually read every word, but rather clump words and paragraphs into "essential meanings" to save time as we read. It seems that by taking shortcuts, we gain some time, and possibly lose something else.

"Modern" education is geared to shortcut thinking. The savants are "weeded out" by our educational system, because they make the teacher's work harder. Teachers have forgotten how to see the world in "raw" terms, without the learned shortcuts. The savants do not fit, so we toss them in with the refuse, or drug the savant out of them.

Yet, never have we needed the savants more than today, when modern societies find themselves in traps of their own making, but without any understanding of what is needed to open the cage door. Political systems are tightening the trap, and every proposed and attempted solution promises to make the situation worse. Political "change" is merely shorthand for a re-dressing of more-of-the-same. Savants have the ability to see elements of a problem that are hiding in plain sight.

An autistic savant is different from a genius savant, or prodigy. A normal person with savant-latency is a different creature still. Presumably, after the brain stimulation is turned off, the normal-cum-savant reverts back to normalcy. Autistic savants and prodigies typically retain their gifts for much longer periods of time, although not always permanently. Most of us probably wish to be polymaths, which may be possible eventually, with more advanced brain stimulation, or brain machine interfaces.

Here is more about the polymath.

More on Snyder's work here.

BTW, check out the new blog Brain Stimulant, if you are interested in brain electromagnetic stimulation.

Peel Scalp, Open Skull, Apply Electrodes

Medical indications for the placement of brain electrodes are multiplying. Parkinson's, paralysis, pain control, epilepsy, depression, deafness, blindness, and many more. It is good that the techniques for brain electrode implantation are growing more sophisticated.

1. Electrodes on the scalp can only detect electrical waves that have passed through the skull, producing a weak signal susceptible to interference from mains electricity and other sources.
2. Electrodes implanted directly into the brain produce much clearer signals, but are not well tolerated by the body. "The brain tries to get rid of [the electrodes] by covering them with a sheet of tissue," explains Schalk. "The signal degrades over time."
3. Schalk and colleagues at Albany Medical College, Washington University in St Louis, University of Washington, Seattle, and the University of Wisconsin at Madison, all US, think a third approach will face fewer hurdles...They cover part of the brain's surface with a polymer sheet containing a grid of electrodes 2 millimetres in diameter and spaced 10 mm apart, a method called electrocorticography (ECOG). Such electrode grids are often placed in people with severe epilepsy to identify the focus of seizures within the brain.

"These grids are thin like a sheet of paper," says Schalk. "The electrodes record signals similar to those recorded by electrodes on the scalp, but with much greater fidelity."___ NewScientist

So far, the new approach looks good for long-term electrode array implantation. As the electrode arrays become more sophisticated, so do the possibilities for communication between the brain and electronic machines.

'When we turn the current on, the patients report the emptiness suddenly disappears'...By inserting electrodes into the brain while the patient is conscious (so that the surgeon knows if they have hit the right spot), Dr Mayberg found remarkable results. When she published her work, she said: "In the operating room, when we first turn the current on and get into the right location, the patients report that the heaviness or emptiness suddenly disappears. If they had a sense of a black cloud, they report it physically lifting."

The moment the electrodes were turned off, some of the positive effects vanished, but the overall results - four out of six patients were lifted from depression for six months - were encouraging.___Source

Wireheading is the science fiction concept of being able to connect the brain directly to an external electronic signal--for either "electronic bliss" or for purposes of high level communication with sophisticated computing devices (or with other wireheads).

The more sophisticated the brain electrode arrays, the more sophisticated the possible mind-machine or mind-mind interactions. "Brain chips" are already learning how to transfer neural signals across a "brain necrotic divide," as from a stroke. Such chips are slowly growing beyond mere relay stations, to learning to decode simple neural signals. As such experience grows, neurochips will learn even better neural communications skills.

In the brain, it is all about the connections, the timing, the amplitudes, and the frequencies. The smart approach to learning our way around brain signaling would be to implant smart arrays of electrodes that merely sit, watch, wait, correlate, analyse, theorise, and test theories. It goes without saying that such experiments with passive brain electrode arrays would also contribute to machine cognition research. Conversely, better machine cognition based upon brain emulation, would provide neuro-researchers with better models for testing theories and hypotheses.

Just getting started? No, just starting to get started.

Electromagnetic Brain Stimulation: More on TMS as Depression Treatment

Electromagnetic brain stimulation has been used for Parkinson's,... Alzheimer's,... Tourette's,...dystonia,... simply for overall "brain boosting."

Here is a recent look at using transcranial magnetic stimulation (TMS) for depression:

"This study provides new support for the efficacy of TMS (transcranial magnetic stimulation) as a 'stand alone' treatment for depression," said John Krystal, editor of Biological Psychiatry which will publish the study on December 1.

"This finding could be particularly important for patients who do not tolerate antidepressant medications, for whom they are not safe, or who have not benefited from other alternative treatments."

The treatment works by sending very rapid bursts of magnetic energy into the brain through coils attached to the scalp.

These pulses cause the neurons in a small area of the brain to "fire off," said study co-author Philip Janicak, a psychiatry professor at Rush University Medical Center in Chicago.

.... This is the first large-scale study of the technique and researchers also used much higher doses of the energy pulses.

Remission rates among those who received the treatment were twice as high as those receiving a "sham" treatment where a shield was placed on the coils.

They were also higher than average rates in antidepressant drug trials, Janicak said.

This is particular significant given that most of the patients in the study had failed to respond to antidepressants - a criteria which would have excluded them from most drug trials, he said.

Researchers in at 23 sites in Canada, the United States and Australian randomly assigned 325 patients suffering from major depressive disorder to nine weeks of magnetic stimulation or a sham treatment.

Physorg

We are a long way from understanding the complex structure and function of the human brain, and how it shapes our behaviour and conscious experience. Better methods of mapping microscopic nerve pathways in the brain should help, as should better real-time brain imaging techniques used in conjunction with targeted neuropsychological testing.

Using TMS, deep brain stimulation (DBS), neural interface chips, and other non-pharmacological methods of targeted modifying of brain pathways and nuclei should give researchers and clinicians more options for study and treatment of normal and pathological brain/mind processes.

Curing Brain Cancer With Electric Fields

Israeli researchers have published results of a study using electric fields to successfully treat patients with the rapidly growing brain cancer glioblastoma multiforme (GBM).

A device that specifically targets rapidly growing cancer cells with intermediate frequency electrical fields -- called Tumor-Treating Fields (TTFields) -- doubled the survival rates of patients with brain cancer, according to a Proceedings of the National Academy of Sciences (PNAS) journal article.

Early results of cell culture, animal and early phase human trials showed that compared to historical data, the device more than doubled the median overall survival rates in patients with recurrent glioblastoma multiforme (GBM), the most common and aggressive type of malignant brain tumor. These survival rates observed in the data were compared to historical data.

Professor Yoram Palti of the Technion - Israel Institute of Technology, the leading Israeli biomedical research institution, invented the device and first described it in a journal article in 2004.

It uses electrical fields to disrupt tumor growth by interfering with cell division of cancerous cells, causing them to stop proliferating and die off instead of dividing and growing. Healthy brain cells rarely divide and have different electrical properties than cancerous brain cells. This allows the device to target cancer cells without affecting the healthy cells.

Source

Here is a link to a journal article describing the technique.

This technique appears to offer promise for other types of tumours that can be as easily accessed with external electrical fields, with much less serious side effects than with chemotherapy, radiation, or neurosurgery.