Month: March 2003

What’s Connecting the Neurons?

Neurons communicate via electrical pulses that shimmy down long branches called axons and dendrites. It is the emergent communication from these vast networks that somehow bring about complicated, high-order function in our body’s nervous system.

But how are these branches formed in the first place? How do the axons and dendrites know where to go so that the “correct” function results? This is an enormous question and many researches are experimenting with how neuron networks actually develop (this will later be highlighted in our upcoming academic research topical category).

Understanding this developmental process is critical to fabricating functioning neuron devices in silicon. If the neurons are to grow and live happily on a computer chip, then the environment on that chip must be just right for the finicky brain cell.

Also, if the route to fabricating the device is to have baby neurons grow their branching networks on their own (which is a typical method used by researchers), and if we want the device to result in a specific function, then it might be very important to know how to guide the growing branches to the appropriate neighboring neuron (although this will be an important point of debate).

John Thomas, a professor at the Salk Institute, has recently reported on an important discovery on a certain protein interaction occurring in the neuron’s environment that signals to a growing branch to “go the other way!” Read more about this work, and consider how it could be a vital bit of biology that will aid in controlling how neurons may develop and live in a silicon world.

Read the article from ScienceDaily News ]

Towards an Artificial Synapse

Neuron devices–little silicon chips that “plug in” to your brain–being developed today tend to function with the idea that electrical pulses can be used to stimulate activity in neurons living either on the chip or in surrounding brain tissue.

The next important step to ensuring a successful neuron device is to have the neurons actually communicate with one another, so that the new electrical stimulation can be processed by the brain. This communication between neurons actually happens by the direct transfer of chemicals from one neuron to the next via very small knobs, called synapses. If stimulated by electrical activity in the neuron, these act like shower heads that spray specific chemicals into a branch, or dendrite, of a neighboring neuron. These chemicals then determine how the neighbor neuron will respond to the first neuron.

Mark Peterman and Harvey Fishman at Stanford University, are working on another approach for neurotechnology by creating a silicon device that contains “artificial synapses” that directly deliver the necessary chemicals of communication to neurons.

Read more about this very interesting development reported in New Scientist.

Read the public release announcement on Eureka Alert ]

Read the article from New Scientist ]

03/27/2003 UPDATE
Read an article from ITWeb in South Africa ]

The Politics of Consciousness

There is an important connection between neurotechnology and human consciousness, which is why Neuron News dedicates an entire category to the subject. The neurons in our brain somehow make us feel aware of ourselves and conscious. Neurotechnological devices will either integrate new neurons into our brain or alter the function of existing neurons in some way.

So, if these brain-chips are tinkering around with our neurons, it might be important to understand how that will affect our brain function on the whole, in particular our consciousness.

Christof Koch, at CalTech, and Nobel Laureate Francis Crick, at the Salk Institute for Biological Studies and whose name is famously tagged with the double helix structure of DNA, have been working on the problem of how brain cells make us conscious for many years. This article briefly outlines their current set of ideas on the issue of the “neural correlate of consciousness” and suggests that we have cut-throat politicking going on up in our heads.

Read the article from Billings Gazette ]

[ Visit the Koch Lab ]

Jeff Hawkins dabbles in the Brain

In 1994, Jeff Hawkins invented a slick little device called a PalmPilot, and started the company Palm Computing. Due to reasons we won’t discuss here, Jim sprouted off of Palm to found Handspring, now a competing, although compatible, device to Palm.

Interestingly, behind all of this successful entrepreneurial drive is really a deep interest in understanding how the brain actually works. Early in his career path, Jeff was a graduate student in biophysics hoping to be directly involved in neuroscience research in the academic world. His thesis was not accepted because he was working independently from a professor, and that was against the rules. So, he decided to go back to work in the real world, make a ton of money, and do neuroscience on his own later in life.

Read a more detailed biography of Jeff Hawkins’ early days and career development from Pen Computing. ]

And that is exactly what he has done. Jeff went out and made a lot of money (and he surely still does). The ideas he studied in graduate school stayed very close at hand during his years of technology development, but his dream has now come true since founding the Redwood Neuroscience Institute in Menlo Park, CA in August of 2002.

The mission of this exciting research organization is to study and promote “biologically accurate and mathematically well-founded models of memory and cognition”. RNI primarily supports an in-house scientific team working on these issues, presumably anticipating start-up spin-off companies in the future, but also plans to fund external research through grants.

The following articles are interviews with Jeff Hawkins that discuss his interest in the brain and what he thinks is the most important routes to its understanding.

Read the article from PDALive.com ]

Read the article from Fast Company ]

Plug Your Memories Back In

The first test of an actual silicon device will soon be performed to help restore function to a slice of tissue from a rat’s damaged hippocampus!

This news item has been splashing into headlines all over the world yesterday and today, so we’re trying to keep track of the journalists’ take on the issue. As we keep finding more links, we’ll update this post.

Theodore Berger and his team at the University of Southern California have been working for years to develop mathematical models that represent the appropriate computations performed in the hippocampus of the brain, the area of your brain which is widely accepted as a major storage container and processor of memories. These models would then guide the design and fabrication of an actual silicon chip to be directly integrated with the brain tissue.

However, fully understanding the mechanisms of specific computations in our brain is still beyond scientists’ desperate grasp, so Berger’s team listened to neural activity and attempted to encode what they saw it into silicon.

To accomplish this, a silicon chip is fabricated with tiny electrodes–basically little metal pads and wires–that sit nearby active, non-damaged neurons and receive their electrical signals that are supposed to be providing “input” to damaged neurons. These captured input signals are transmitted by the embedded silicon chip to another chip sitting outside the brain. The external chip is like a mini-computer that processes these electrical signals according to Berger’s model of how the hippocampus is supposed to function. Based on this on-chip processing, it finally sends new electrical signals back down to the non-damaged neurons.

These computer-generated electrical signals are meant to exactly replace the electrical signals that would have resulted from the neurons receiving the original input, but couldn’t do so because they were damaged in some way.

Important note: This prototype brain prosthetic has been specifically programmed to function in a certain way–a way that neurons in a rat’s hippocampus presumably communicate. A successful test of this device will show that if the hippocampus is “turned off” in an animal and the device “turned on”, then normal brain activity resumes.

This would be a great step forward in developing technologies that replace damaged function in our nervous systems. Forgot where your keys are? Can’t find where you placed your presentation material due to your boss in exactly 1.2 minutes? No problem, just don’t forget to turn on your “memory chip”.

Maybe that’s where we are headed, but not by just copying our neural activity from when we were still healthy. One of the articles below mentions the concern that since what we consider to be our “self”, likely has a great deal to do with our memories, then a prosthetic device that has strict and static on-board processing rules, might somehow alter who we really “are”.

Certainly, more must be understood about how our brain functions in general, but this upcoming test is still very exciting!

Read the article from the New Scientist ]

Read the article from Ananova ]

Read the article from MSNBC.com ]

Read the article from BBC News ]

Read the article from the Guardian ]

Upgrade Yourself to Greatness

Slate Magazine presents a special series on “Building a Better You”

The ultimate extension of neurotechnology promises to offer power interfaces between brain and computer providing enhancements to your body, which has already evolved into an amazing machine in and of itself.

Scientists, engineers, and even the US Department of Defence are working toward many goals to improve our body’s mechanical characteristics (run down to the local market for a gallon of milk and be back before the commercial break is over) and mental abilities (oh, e=mc^2 is so trivial). These technological developments are already showing successful applications, and many more will appear in the next several decades, if not much sooner.

Read Slate Magazine’s review of the current state of scientific progress in the business of upgrading your body–literally–to make you into a “better you”.

Building a Better You
a special series from Slate Magazine

Read the introduction ]

Read about improving your eyes for SuperVision ]

(This series is still being written by Slate Magazine, so more links will be updated right here as they become available.)

Last updated April 5, 2020