Phantom Limb

Phantom Limb syndrome is such a mysterious symptom for patients who suffer from it. For those of you who don’t what it is; phantom limb pain is mild to extreme pain felt in the area where a limb has been amputated. Although the limb is no longer there, the nerve endings at the site of the amputation continue to send pain signals to the brain that make the brain think the limb is still there. Sometimes, the brain memory of pain is retained and is interpreted as pain regardless of signals from injured nerves. While some patients go through it for only a couple of months, others who are more severe can suffer through it for years. There are multiple ways to treat phantom limb based on the person’s level of pain such as; heat application, biofeedback, or neurostimulation. But most of the time doctors would prefer using non-medical approaches; like relaxation techniques, massage, or physical therapy. Now they created a new type of treatment known as mirror therapy. 

Mirror therapy is a primary tool of this therapy is a mirror from which the patient receives visual feedback in order to train the brain to configure a new “body map.” What is a body map you might ask, this so-called map is simply the hard-wired mental representation that allows a person to be aware of where each component of the body is at all times, even in complete darkness. The patient places the affected limb in the mirror box, which keeps the injured part out of view. An alternative setup is to have the patient sit at a right angle before a mirror so that only one side of the body is reflected back. The point is to move both limbs in a coordinated manner so that they mimic the movement of the other. 

Studies show that the majority of patients typically experience sensations in the phantom limb very quickly after starting this exercise. It’s interesting how your mind can play tricks on you. Though you think you know what is real and what is not, the question is, do you really?

Brain Mechanisms of Pleasure and Addiction

In the beginning, 1954 to be exact, psychologists James Olds and Peter Milner wanted to study more on brain mechanisms. Olds and Milner began testing on rats (rats had the closest brain structure to humans) to see whether stimulation of a certain brain area might influence which direction a rat turns or in their words, "Ask animals how they felt."

They would implant electrodes in rats septum of the brain and placed them in boxes where they could press a lever to produce electrical self-stimulation of the brain. With electrodes in the septum and certain other places, rats sometimes pressed as often as 2,000 times per hour. Later on researchers found many brain areas that rats would work to stimulate. All those areas had axons that directly or indirectly increase the release of dopamine or norepinephrine in the nucleus accumbens.

The nucleus accumbens is central to reinforcing experiences of all types. And maybe it was true; that drugs possibly created this sense of pleasure because they stimulate the same areas in the brain just like sex or food. If you simply imagine something pleasant, you activate your nucleus accumbens.

They also developed another experiment to see how far rats would go for stimulation. They electrified a grid, so that every time the rat crosses to the other end of the grid in order to reach the pedal that would stimulate the brain, it would receive a painful shock to it's feet. Do you think the rat would take that risk? Unfortunately, it would; a rat that craved for stimulation is like how they described it, "like a starving rat brave to get food."

Thanks to Olds technique of self-stimulation of the brain, it gave other scientists a way to test the addictive potential of drugs and to find out where in the brain they acted. Reinforcement has two components that psychologists called "wanting" and "liking." Most of the time, you would want something that you liked, but in the end, wanting (motivation) is not always the same as liking (pleasure). When it came to addictive drugs, the liking-wanting distinction was important because research showed that people addicted to a drug showed an overwhelming, all-consuming drive just to obtain the drug, even though it no longer provided much pleasure. When scientists found out that nearly all abused drugs would increase dopamine release in the nucleus accumbens, they concluded that by removing the dopamine neurons out of the brain, it would decrease their self interests such as drugs.    

From the information I processed from the video, it got me thinking; if scientists who study on addictive drugs know from which area produces self-stimulation of the brain from that drug, and know they can remove it, then why haven't we (or at least I haven't) seen this procedure being done more often? Most of time you would see drug addicts going to counseling or rehabilitation centers. So why is that? Is it because the procedure is not FDA approved, it's too expensive, hmmm...

Blood-Brain Barrier: A Closer Look On How It Works

The BBB is to protecting the brain internally as the skull is to protecting it externally. The problem is the BBB does not differentiate what it keeps out. Life-saving chemicals, if they happen to be the wrong chemicals, simply won't get through. With very few exceptions, only small molecules soluble in fat clear the barrier. Only two percent of small-molecules get through. These include alcohol, caffeine, and nicotine.

Small-molecule compounds have been used to treat affective disorders, schizophrenia, chronic pain, and epilepsy, but they leave a lot to be desired. The problem, says William Pardridge MD of UCLA writing in the Jan 2003 Archives of Neurology, is that "small molecules are largely palliative medicines with often unfavorable safety profiles."

Dopamine is one of those types of small molecules, but unfortunately, their chemical structure stops them from passing the BBB. However, L-DOPA can follow a certain type of amino acid transporter through the BBB without even knowing it.

Dr. Pardridge and his team have been experimenting on encasing genes in liposomes coated with what they called a special polymer in order to attach them with antibodies. Why antibodies? The antibodies are the ones that sneak their way pass the brain-capillary receptors so the liposomes could complete their mission. In one of their experiments, they injected rats that had Parkinson’s with liposomes containing a gene that “boosts production of the enzyme tyrosine hydroxylase,” (a building block of dopamine). The rats’ abnormal symptoms were then reduced up to 70% three days later. By completing multiple experiments with the same procedures, rats with brain tumors doubled their lifespans. With weekly injections, delivery of antisense RNA that blocked production of a malignant growth factor was a success.

What’s the point in finding the cure to a neurological disease, if there is a high possibility that it won’t even make it pass through the BBB  in order to receive the full effect?  Since there is no academic neuroscience program that focuses on BBB transport biology or drug targeting, who knows how long it would take for it to become funded with the technology and research.  For example, if someone is trying to sell you a product that is 99% effective, wouldn’t you feel more confident if it had that one last percent? But once again, the Blood-Brain Barrier only has a two percent chance for the medication to become in full-effect. So would you take that risk? These are the kind of things that makes you wonder.

Mind Reading - FMRI - Machine that Reads Your Thoughts - 60 Minutes

An fMRI is mostly used as a diagnostic method of choice for learning how a normal, diseased or injured brain is working, as well as for assessing the potential risks of surgery or other invasive treatments of the brain. But did you know that it is also a machine that could read peoples thoughts? It was amazing to see a conduction of an instance analysis on a participant to prove their theory (identify the participant's thoughts in "real time"). With the combination of an fMRI and massive amount of computer data, they could detect for example; if the participant had seen an image of a "hammer", then the computer would respond that it was in deed, a "hammer". Another study they experimented on was reading a persons intentions; by deciding whether to add or subtract two numbers that were shown later on after the test. Once they finished scanning the participant and collected the images, they redirected to the active area of the brain that controls intentions to see what the participant had decided. You could really tell the difference between the patterns of when they either added or subtracted. It was true; an fMRI was in fact, a thought identification machine. The question is, should we use it for other purposes other than treating the brain? It could be used as another form of lie detection in situations such as; finding the real truth from a criminal or even a patient with an unknown disease. Everybody lies, but would you do an fMRI scan to prove your honesty?