Ask a Scientist followup, part 3

One question I received on Tuesday night was whether there is any potential for treating residual paralysis resulting from Guillain-Barré Syndrome with neurostimulation or BMI. I'll try to answer the question here, but please be aware that I'm not an expert in GBS.

Guillain-Barré Syndrome is an autoimmune disease in which peripheral nerves are damaged or destroyed by the body's own defenses; often, it starts as a response to a genuine infection. While recovery is possible (or even probable with modern treatments), it is not uncommon to have residual weakness, paralysis, or other problems.

In this paralysis, the peripheral nerves leading to the muscles are damaged or destroyed; this limits the options for neurotech treatment in a few ways. I can't think of any brain-related therapy that would help much, since the connection to the muscle is fundamentally damaged. Furthermore, muscles degenerate somewhat when innervation is lost, and after a certain point this is not completely reversible.

FES (functional electrical stimulation) is more appealing. However, since the peripheral nerves are damaged, a FES system would need to directly stimulate muscle, which is much more difficult than simply stimulating the nerves.

Until something like this is developed, direct stimulation of the muscle may help with strength (if any connection to the muscle remains) and help maintain flexibility / viability of the muscle. This is called NMES (neuromuscular electrical stimulation) or EMS (electrical muscle stimulation), depending on who you ask. It's an odd field in part because many of these devices are used as "ab enhancers," but it is scientifically legitimate and a rehab specialist will be able to tell you more.

Ask a Scientist followup, part 2

After mentally replaying one of the final questions from last night, I may have misspoken regarding the well-known work on light-activated neurons from Karl Deisseroth's lab at Stanford. I think part of my brain was still answering the question about voltage-sensitive dyes and the like... and I said at one point that the modified neurons were a visualization tool.

Of course the whole point is that modified neurons can be activated or inhibited, with fine control, using light as a stimulus. This amazing tool has already yielded significant insights into neuro-questions, including shedding some light on how deep brain stimulation (DBS) for Parkinson's disease works.

Sorry for any confusion!

Ask a Scientist followup, part 1

Last night's Ask a Scientist SF talk went very well - a big "thank you" to everyone who turned up or helped organize the event. There were at least two hundred people in attendance, and some great questions/discussion on all things neuro. I'll publish my slides in the upcoming week, and will publish the link to the video on fora.tv when it becomes available.

I'll be following up on some audience questions in these entries. First, someone came up and recommended that I look up "cranching" in classic science fiction. The reference is to a Cordwainer Smith story from 1950, in which humans disconnected from their senses and emotions via implanted devices serve as a fraternity of interstellar pilots. Cranching is their temporary return to humanity. Saying much more would spoil the reading, so I'll simply add a link to the publicly-available fulltext: Scanners Live in Vain. It's classic, timeless SF, and highly recommended.

Brain-machine interface with cortical EEG

Every time I think about brain-machine interface, and how hard it is to get right... I find myself more and more drawn to the cortical / epidural approach pioneered by Dan Moran and Eric Leuthardt at Washington University in St. Louis. Scalp EEG is simply too blurry, as much as we may wish otherwise. And single-unit depth electrodes are just too hard to keep stable. Here's a link to a paper describing the work. Best of luck to the Washington U group; I'll be following your progress and hopefully reporting great things.

Primitive neuromodulation

Did you know the first neurostimulation was done with electric eels and torpedofish, for pain? It worked, too... makes much more sense than a lot of things that have been tried in the last few decades of neurotech.

Here's a better summary of the history of pain treatment than I could ever provide, courtesy of St. Jude. I think I'll stay away from that Violet Ray.

Speaking at Ask a Scientist SF - January 19th

On January 19th, I'll be speaking at Ask a Scientist SF on the topic of neuromodulation and brain-machine interface. The talk will be recorded by Fora.tv and will be available online. I'll post more news as it becomes available.

Tuesday, January 19th at 7:00 PM
Horatius Bistro and Market Gallery
350 Kansas St
San Francisco, CA

Hope you can make it.

Welcome to CORTICAL COLUMNS

A cortical column is a group of cells, connected locally and globally. It is the basic unit of organization in the neocortex - the part of the brain that makes us human, and the part which we understand least.

I hope this blog helps connect neurotech and human behaviour; brain science and engineering development; you, the readers, and myself.

Enjoy.