Banned drug reduces brain communication

Brain connectivity drops in rats dosed with 'bath salts'

Giving rats the stimulant drugs called “bath salts” reduces communication among different parts of their brains, a new study finds.


WASHINGTON — In the late 2000s, a new class of street drugs emerged that were quickly nicknamed “bath salts.” Their name reflected the fact that they looked like small salt-like crystals. Because they were not initially regulated, many teens and others saw them as a “legal” way to get high. That changed in 2011, when U.S. government ruled them illegal. Still, many people continue to use them. A new study now shows why that’s bad. These drugs reduce the ability of different brain regions to communicate, at least in rats.

The finding may explain the paranoia, delirium and aggression that some users of bath-salt drugs experience.

The brain relies on a flow of communications between its different parts. That’s how it processes information. In tests on rats given one type of bath salts, communication levels fell among the 86 brain regions studied.

“The higher the dose, the less connectivity you get in the brain,” concludes neuroscientist Marcelo Febo. “It causes a pretty global reduction.” Febo presented his team’s findings here, on November 15, at the annual meeting of the Society for Neuroscience.

Bath salts work by boosting levels of dopamine (DOPE-uh-meen). It is a messenger molecule related to feelings of reward and pleasure. The drugs also raise levels of norepinephrine (NOR-ep-ih-NEFF-rin) and serotonin (SAYR-uh-TOW-nin). These two brain chemicals are also messengers. They play roles in attentiveness and mood.

Low doses of bath salts can make users feel euphoric and alert. However, things can change just hours after taking one variant, called MDPV (short for 3,4-methylenedioxypyrovalerone). Some users experience a powerful crash. The effects can be unpredictable and dangerous. Users may grow delirious, suicidal or violent.

Febo and his team wanted to investigate the lingering effects of bath salts on the entire brain. The researchers gave doses of either MDPV or salt water to 46 laboratory rats. The experts then waited an hour before scanning the rats’ brains with functional MRI. This special machine uses strong magnetic fields to study brain activity. Among the brain regions in rats given MDPV, levels of synchronized activity dropped broadly.

That change may explain the erratic behavior seen in some people who take bath salts, said Febo, of the University of Florida in Gainesville. The same effect also can occur in people who chronically abuse cocaine and other drugs, he added.

Febo’s team must still compare the effects of MDPV to those of other chemically related stimulants. These include amphetamine (am-FET-uh-meen) and cocaine. So far, attempts to scan the brains of rats dosed with cocaine made the animals too unstable to obtain results.

Without a comparison, the data lack context, said Michael Baumann. He is a neuroscientist at the National Institute on Drug Abuse in Baltimore, Md. “They’re really big findings,” he said. “But the question is, ‘Do other stimulants do this?’ Or is it unique to bath salts?”

Bath salts have nothing to do with bathing. The nickname for this family of drugs comes from their resemblance to the Epsom salt crystals sprinkled in bathwater.

Power Words

amphetamines     Potent drugs that stimulate the brain. They can be used as a medicine to treat attention deficit hyperactivity disorder (ADHD) or other types of disease. However, these can be habit forming (somewhat addictive) and in high doses can provide euphoria, delirium and other symptoms similar to cocaine.

bath salts      The common name, or street name, given to a class or illegal drugs. They get their name from their resemblance to the Epsom salt crystals that some people sprinkle in bathwater to soothe sore muscles.

context     The setting or circumstances that help explain an event, some statement or some conclusion.

delirium      A symptom of mental upset where people become seriously confused or out of touch with what’s happening in their environment. They may no longer realize where they are, how they got there or what’s happening to them. Fevers, some drugs and some sorts of mental illness can all trigger temporary periods of delirium.

dopamine   A neurotransmitter, this chemical helps transmit signals in the brain.

erratic     An adjective that describes omething that happens at unpredictable intervals or a behavior that is unpredictable.

euphoria    A sense of great joy, excitement, self-confidence and/or intense well-being.

fMRI (functional magnetic resonance imaging)  A special type of machine used to study brain activity. It uses a strong magnetic field to monitor blood flow in the brain. Tracking the movement of blood can tell researchers which brain regions are active. (See also, MRI or magnetic resonance imaging)

neuroscience   Science that deals with the structure or function of the brain and other parts of the nervous system. Researchers in this field are known as neuroscientists.

norepinephrine       A type of stress hormone secreted by the adrenal glands. It constricts blood vessels. It also increases the force and rate at which the heart contracts.

paranoia     The feeling of persecution — that people are out to “get” you — or that other people cannot be trusted. It can cause the affected person to feel intense anger, hatred or a sense of betrayal.

serotonin   A chemical present in blood that constricts blood vessels and communicates signals in the brain and nervous system. 

stimulant   Something that triggers an action. (in medicine) Drugs (including caffeine) that can stimulate the brain, triggering a feeling of more energy and alertness. Some dangerous illegal drugs can do this too, such as cocaine.

unique      Something that is unlike anything else; the only one of its kind.

variant    A version of something that may come in different forms. (in biology) Members of a species that possess some feature (size, coloration or lifespan, for example) that make them distinct. (in genetics) A gene having a slight mutation that may have left its host species somewhat better adapted for its environment.

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