The central nervous system is formed by the brain and the spinal cord. As we all know, the brain is the organ that generates ideas and processes information. Among many different functions, the brain controls the motor function of the body. In other words, if we want to walk, the brain generates a command ordering the legs to walk. Similarly, if we want to grab a glass of water with the left hand, the brain generates a command to the left hand to grab the glass of water and so on...
These "commands" are generated in the form of neural or electrical signals and are transmitted through the spinal cord to the rest of the body. But transmitting the motor information generated by the brain is not the spinal cord's only function. The spinal cord is also a conduit of sensory information from the rest of the body to the brain (like when we touch a hot surface with a hand and the heat sensation travels from the hand through the spinal cord to the brain) as well as a center where some reflexes are coordinated.
For the purpose of this post, we will concentrate on the spinal cord's motor information transmitting function. Traumas to the spinal cord may result in the cord being crushed, bent or even severed. Patients that suffer spinal cord injuries have to deal with different degrees of paralysis. For example, much like the transmission of internet service at your home, the brain (your modem/router) receives and transmits signals through the spinal cord (the wiring in your house) to your hands and legs (computer). If any part of the wiring is damaged (crushed or severed) the internet signal (neural or electrical signals) transmitted by the modem/router (brain) will not reach the computers (arms, legs, etc.).
Unless the wiring is repaired...
Some researchers are studying the use of stem cells to help regenerate the damaged spinal cord tissue (wiring). For the process to work, the stem cells have to be correctly aligned and delivered to the injured area. Moreover, the cells have to be induced into "grouping" and "sticking" together around the injured area until they have completed the regenerative process. This is accomplished by using "signal proteins". However, since "signal proteins" are typically absorbed by the body before the regenerative process is completed, researchers have had to create man-made nano filaments that form a sort of "scaffold" that keeps the cells together long enough for full regeneration to take place. Once the stem cells have done their regenerative job, the body absorbs the nano filaments and no traces of the process are left behind.
Other companies have created similar devices: InVivo Therapeutics Holdings Corp., has created a biocompatible polymer-based scaffolding device that also helps group and keep together the stem cells for the duration of the regenerative process.
Or, Unless The Spinal Cord Is Bypassed Altogether
Now scientists have come up with the idea of bypassing the spinal cord entirely. Think of it as having a wireless modem/router (brain) and a wireless computer (arms and legs) at home: no need to use the wiring inside your walls (spinal cord)...Researchers at Northwestern University in Chicago have managed exactly that: the bypassing of the spinal cord using a brain-computer interface.
Scientists have created a neuroprosthesis that combines a brain-computer interface (BCI) that is wired directly into approximately 100 neurons in the motor cortex of the patient's brain with a functional electrical stimulation (FES) device that's wired into the muscles of the patient's arm. For example, if the patient chooses to move his hand, the cluster of 100 neurons activates and generates a stream of data that is sent to the brain-computer interface. The BCI then reads and analyzes the data and selects which muscles (and with what degree of force) the patient is trying to move. This data is then wirelessly sent to the FES device, which makes the right muscles move.
It is important to note that Functional Electrical Stimulation (FES) devices have been in use for years. However, those previously tested devices have had pre-programmed basic movements (like a command to open a hand or lift a leg) that are triggered by small muscle movements in non-paralyzed muscles. As opposed to these older devices, the BCI does not respond to "second-hand" signals, but to a normal array of neural signals generated by those 100 neurons in the cerebral cortex.
Of course, this Brain-Computer Interface has only been tried in primates and we are a long way from human trials. Yet, it is exciting to know that such science fiction like technology is not only possible, but is already being tried. Maybe the idea of having a computer chip in our brain that wirelessly interfaces with our other electronic devices is not that farfetched. Perhaps answering the phone in the relatively near future will be a matter of blinking one's right eye...
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