On Mice and Cocaine

Every once in a while you might hear someone complain about some odd science experiment in which a university spent some money doing something that might seem nearly nonsensical. To wit, did you hear the one about the team at UC Berkley that observed mice on cocaine?

You know, I forget the details of the old story about giving chimpanzees cocaine, but it was something like you would expect, that the group stratified unnaturally and generally began behaving like drug addicts. Even then, though, people are dubious about the value of such scientific inquiry.

Which brings us back to the point: Why would you give cocaine to mice?

And the answer:

Cocaine can speedily rewire high-level brain circuits that support learning, memory and decision-making, according to new research from UC Berkeley and UCSF. The findings shed new light on the frontal brain’s role in drug-seeking behavior and may be key to tackling addiction.

CocamausLooking into the frontal lobes of live mice at a cellular level, researchers found that, after just one dose of cocaine, the rodents showed fast and robust growth of dendritic spines, which are tiny, twig-like structures that connect neurons and form the nodes of the brain’s circuit wiring.

“Our images provide clear evidence that cocaine induces rapid gains in new spines, and the more spines the mice gain, the more they show they learned about the drug,” said Linda Wilbrecht, assistant professor of psychology and neuroscience at UC Berkeley and lead author of the paper published today (August 25) in the journal Nature Neuroscience.

For mice, “learning about the drug” can mean seeking it out to the exclusion of meeting other needs, which may explain how addiction in humans can override other considerations that are necessary for a balanced life: “The downside is, you might be learning too well about drugs at the expense of other things,” Wilbrecht said.

Using a technology known as 2-photon laser scanning microscopy, researchers made images of nerve cell connections in the frontal cortices of live mice before and after the mice received their first dose of cocaine and, within just two hours, observed the formation of new dendritic spines.

It has been said that cocaine is the Devil. Inasmuch as science might have anything to do with such a characterization, let us reiterate the summary: It appears that from the first dose, cocaine begins physically rewiring the brain to make the seeking of cocaine a priority.

This goes well beyond any lock-and-key addiction propaganda they ever gave us as kids to explain why drugs are bad, m’kay?

Obviously, there remains much research to be done about how this process works in humans, but for now at least we know why anyone would want to give cocaine to mice, or mice to cocaine, or otherwise combine mice and cocaine.

In all honesty, I wrote that backwards the first time: Why would you give mice to cocaine? Except, by the psychopathology of everyday life, I’m not sure that was the wrong question.

As near as we can tell, by our own B. D.