Month: June 2002

Zap that pain away

Got a headache? Reach for your favorite pain reliever pill fast… Or, someday you might punch in a code in your hand-held computer and the mind-numbing throbbing would quickly fade away.

Neurosurgeons have long tried techniques to alter the function of spinal cord and brain circuitry. These have been as invasive as cutting tissue and removing small sections of the brain. Patients have ranged from those having severe pain to others with psychiatric conditions (think about what happened to Jack Nicholson in “One Flew Over The Cuckoo’s Nest“).

Now, new techniques are being developed to directly apply a little stimulation from an electrode to a section of the brain handling motor control. Initial attempts are resulting in unexpected and interesting effects of reducing chronic nerve pain and inducing other potentially therapeutic activity elsewhere in the brain.

For the potentially more controversial surgeries to “fix” patients with severe psychiatric conditions who don’t respond to medication or other therapies, doctors hope that strategically-placed electrodes may be an effective treatment to bring some semblance of normalcy back into these patients’ lives.

[Read the article from the San Francisco Chronical]

Read a related Neuron News article ]

Remembering with “Silicon Neurons”

“Where did I put my keys?” “What is the name of that… that one guy who borrowed my car?”Every human tends to be forgetful now-and-then. Our memories will become even worse if actual damage occurs to brain cells from a stroke or advanced Alzheimer’s disease. One optimistic outlook for brain-implanted neuron devices is that they could be used to help keep our memories sharp, or at least replace the function of lost neurons critical for remembering the names of your loved ones.

Prof. Theodore Berger at the University of Southern California is working on developing circuits that can be used to fill a functional gap due to damaged neurons. Their interesting approach to developing “bionic” chips is to implant a silicon processor into the hippocampus to interface with existing neurons. (This part of the brain is considered to have a significant role in memory function.)

At the time of this article, the group has not demonstrated an actual implanted chip calculating away inside a living brain. Rather, they have mathematical models that have guided their chip’s circuit design. Simulations show that these things might work, but it all depends on how well the initial models were set up. They also don’t talk too much about how they plan to interface the silicon chip’s electrodes with existing neurons in the brain. This will be the critical step for a successful implanted device. We’ll keep a close, and excited eye on this group from USC!

[Read the article from the International Herald Tribune]


Neuron Groups Strike a Pose

In order for implanted neuron devices to successfully be used as a corrective tool for neurological disorders, it is critical that we have an understanding of exactly how the electrical activity between neurons corresponds to actual physical movement of the body.

A Princeton University team recently took electrical measurements in a monkey’s brain suggesting that groups of neurons in the motor cortex (generally near the surface of the top of your brain) controlled complicated physical postures. This is in significant contrast to the prevailing view that these motor neurons only control specific muscles.

This is an interesting new look at brain function because it suggests that small clumps of interconnected neurons can direct much higher-level body function. This might make the barriers to better understanding the brain even higher, since we won’t be able to attribute a single neuron or neuron group directly to a specific part of our body.

So, instead of thinking “this specific neuron that excites a muscle has to talk to this other neuron to excite another muscle, which then has to talk to this other neuron” in order to coordinate the lifting of a finger, we must think more in terms of networks of neurons collectively directing complicated behaviors. It really will become messy if we find different networked groups of neurons controlling the same set of muscles, but resulting in different physical behaviors.

[Read the article from Reuters Health]


Blind man sees stars

Two completely blind patients received a neuroprosthetic implant in April from the The Dobelle Institute. After some reorientation, they can now walk around a room without running into desks and chairs, and even drive a car (on a private course)!

OK, so they can’t quite yet enjoy the subtle strokes of Monet, but they can see flashes of white light from their surroundings of which they must learn to interpret. This is still a fabulous development and a critical start to initiate more technological improvements towards restoring shape recognition and color sensitivity to the blind.

The current device takes images from a small camera mounted on special sunglasses. A computer processes the images and sends some electrical signals directly to the visual cortex (a chunk of brain in the back of your head). These visual system brain cells are stimulated in some unknown way, and the patient sees stars.

This is quite an interesting technique because it bypasses the eyes’ input neurons, and sends information directly to the brain. Recent alternative techniques collect light focused on the retina at the back of the eye. Then the brain may interpret the information through estalished image processing neural patheways, just as if the eye were functioning normally.

A direct shot of visual information to the brain’s visual cortex requires special training of the patients so that they may adopt an understanding of exactly how the pattern of white spots relate to the real world. So, this might not be an ubiquitous approach, but best for patients who have completely damaged or removed retinas from an injury.

[Read the original press release from St. Louis University]

[Read the article from CNN]

Ratbots to the Rescue

This article came out about a month before Neuron News began, so hopefully you will be able to forgive it’s delay. Although news about the “Ratbot” has already spanned the journalism phase space, only at Neuron News will you also receive reasonable commentary!

Dr. Sanjiv Talwar and colleagues at the State University of New York, successfully implanted a neuro-remote control to guide a rat through an obstacle course. With a radio-receiver backpack mounted on the little rodent, commands from a researcher’s nearby laptop stimulated areas in the brain associated with the whisker sensation.

Zap one of the whiskers and the rat feels like it bumped into something. Subsequently changing its course to avoid the “virtual wall”, the rat receives a second zap directed to some “feel good” part of its brain.

“Ooo yeah, that was nice. Maybe there’s another one of those over… here!”

This neural control and feedback mechanism allowed scientists to guide the rat to do things it normally would not like to do. For example, the robot rat didn’t hesitate to walk across well-lighted, open spaces.

The anticipation is that these rodents would be used as real-life guinea pigs to maneuver through earthquake-damaged areas, or wind though a mind field, until it… well… stumbles across one.

Although this report is everywhere, check out these UK versions, along with the original report in Nature:

[Read the article from BBC News]

[Read the article from The Guardian]

[A general report from Nature]

Reference
Talwar, S. K. et al. Rat navigation guided by remote control.. Nature, 417, 37 – 38, (2002). [Read (Subscription required)]

I died and went to …

Very few humans are comfortable with the notion of dying, even those who strongly believe in the here-after (although they might not admit it). Science is still learning a great deal about how the body dies, but there are few forays into what happens after the body eternally falls asleep.

Pim van Lommel and colleagues from the Netherlands published an article in The Lancet, a British medical journal, where they describe a study on near-death experiences. They interviewed 344 revived cardiac arrest patients regarding their recent brush with death, and 18% reported some memory of an experience. Their research approach attempts to obtain more accurate accounts without relying on long-term memories.

Of course, any scientific claim regarding after-death experiences are susceptible to many potential problems and critiques, like the occurrence of false memories or the unconscious brain misinterpreting activity from its environment. The Washington Post article below does a nice job of putting the research in perspective, so you should definitely read it carefully.

Wouldn’t it be nice, though, to know what will really happen to us after we close our eyes for the final time? What do you think?

[Read the article from the Washington Post]

[Read commentary from a reasonable skeptic in The Lancet]

If you really want to read about this to form your own opinions, read the published article: Pim van Lommel, et al., “Near-death experience in survivors of cardiac arrest: a prospective study in the Netherlands” The Lancet 358, 9298 (2001)

NOTE: I have not read this article completely, but will report back when I do for more commentary and perspective right here on Neuron News.

Last updated April 5, 2020