From the DEC/JAN 2006 issue of Seed:
CHEMICALS CAN CURE ADDICTION
Credit: Elizabeth Huey
With health and social costs of more than $500 billion a year, drug and alcohol addiction is among the most damaging diseases in the U.S. While neuroscience has made great strides in understanding the basis of addiction (it involves floods of dopamine), that knowledge has yet to yield practical results.
This is beginning to change. Two papers published in Neuron show that addiction—at least in rats—is a treatable medical problem. Each took an unconventional approach, focusing not on the addictive urge itself but on disrupting the memory of the addiction, the theory being that you can’t be addicted to that which you can’t remember.
The first study, by John Marshall and Courtney Miller of the University of California at Irvine,
attempted to eradicate the memories of rodents with a taste for cocaine. After being administered a drug that inhibits production of the protein extracellular signal-regulated kinase, the rats forgot in which cage they received their fix. The unfortunate rodents had gone clean, and they didn’t even need 12 steps.
The second study, by Dr. Jonathan Lee of Cambridge University, focused on the amygdala, the part of the brain that learns to pair the pleasurable feeling of intoxication with a certain stimulus (say, the neon sign of a favorite bar or the sight of an ashtray). He wanted to see whether turning off a particular neuronal gene could erase the amygdala’s memory. It did. Rats with the silenced gene no longer remembered which environmental cues signaled the presence of drugs.
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HUMAN CLONING IS MORE THAN JUST A HYPOTHETICAL
The headline was alarming: “South Korea Makes Strides in Human Cloning” The reality was not so Huxleyan. Dr. Woo Suk Hwang’s lab had come up with an extremely efficient method of producing stem cells. First, they created embryos that were exact genetic matches of individuals. After letting the embryo divide a few times, they extracted its stem cells. This method—known as therapeutic cloning—is one of the most promising approaches in the stem-cell field. Researchers believe that therapeutic cloning will one day be used to create replacement tissues for a variety of diseases. Hwang made it look easy.
Three months later, Hwang made headlines again: After working for more than 900 consecutive days, his lab announced they had cloned man’s best friend, the dog (an Afghan hound named Snuppy). At first glance, that may not seem like such a big deal; after all, scientists cloned Dolly the sheep a decade ago. But for a variety of reasons, dogs had been notoriously difficult to clone. (Dogs ovulate unpredictably, their eggs require surgery to extract, and their embryos won’t grow outside the uterus.) Nevertheless, Hwang says, “Dogs can be good models for human diseases. Dogs [can contract] more than 50 diseases that are similar to human diseases.”
The fear is that Hwang’s techniques may open the door to human cloning before the many ethical issues it raises have been adequately addressed. Hwang himself is unapologetic. Regardless, his technical brilliance showed that it’s no longer just a theoretical possibility.
AT THE DAWN OF TIME, THERE WAS A PERFECT LIQUID
Credit: Brian Ulrich
In the timeless time after the big bang, when the universe was as new as it was empty, there were only quarks and gluons. Atoms had to yet to coalesce. But what was this proto-universe like? In the nanosecond before there was matter, what was there?
There was a perfect liquid. Experiments at the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory have demonstrated that quarks and gluons, when freed from their workaday reality as the building blocks of nuclei, become a liquid without viscosity, a fluid that flows easier than water.