Chan's Personal Blog

The placebo effect

DON'T try this at home. Several times a day, for several days, you induce pain in someone. You control the pain with morphine until the final day of the experiment, when you replace the morphine with saline solution. Guess what? The saline takes the pain away.

This is the placebo effect: somehow, sometimes, a whole lot of nothing can be very powerful. Except it's not quite nothing. When Fabrizio Benedetti of the University of Turin in Italy carried out the above experiment, he added a final twist by adding naloxone, a drug that blocks the effects of morphine, to the saline. The shocking result? The pain-relieving power of saline solution disappeared.

So what is going on? Doctors have known about the placebo effect for decades, and the naloxone result seems to show that the placebo effect is somehow biochemical. But apart from that, we simply don't know.

Benedetti has since shown that a saline placebo can also reduce tremors and muscle stiffness in people with Parkinson's disease (Nature Neuroscience, vol 7, p 587). He and his team measured the activity of neurons in the patients' brains as they administered the saline. They found that individual neurons in the subthalamic nucleus (a common target for surgical attempts to relieve Parkinson's symptoms) began to fire less often when the saline was given, and with fewer "bursts" of firing - another feature associated with Parkinson's. The neuron activity decreased at the same time as the symptoms improved: the saline was definitely doing something.

We have a lot to learn about what is happening here, Benedetti says, but one thing is clear: the mind can affect the body's biochemistry. "The relationship between expectation and therapeutic outcome is a wonderful model to understand mind-body interaction," he says. Researchers now need to identify when and where placebo works. There may be diseases in which it has no effect. There may be a common mechanism in different illnesses. As yet, we just don't know.

"Surprisingly, this uranium mine's nuclear reactor was well designed. Studies indicate that this reactor was several miles in length. However, for such a huge nuclear reactor, the thermal impact to its environment was limited to 40 meters on all sides. Even more astonishing is the fact that the radioactive wastes have still not migrated outside the mine site. They are held in place by the surrounding geology.

Faced with these findings, scientists consider the mine to be a "naturally occurring" nuclear reactor. The Oklo reactor has been documented for its importance as an analogue (a structural derivative of a parent compound) in the disposal of nuclear fuel wastes. But few people are bold enough to go one step further.

As a matter of fact, many people today know that the reactor is a relic from a prehistoric civilization. It's probable that two billion years ago there was a fairly advanced civilization living at a place now called Oklo.

This civilization was technologically superior to today's civilization. Compared to this huge "natural" nuclear reactor, our current nuclear reactors are far less impressive. The question is: why did such a highly advanced civilization disappear? That's something to ponder about...

Thirteen nuclear reactors existed in prehistoric periods along the 200-metre mine bed, and they were comparable to the modern nuclear reactor in power and heat combustion. This mine had the capability of enabling self-sustained nuclear chain reactions...." This discovery, that shocked the entire scientific community in 1972, has already been forgotten by people today."