Salt stimulates the brain like a drug

Salt triggers similar neurobiological effects

12.07.2011

Drugs stimulate the brain in a similar way as eating salt. American and Australian researchers came to this conclusion in a comprehensive study comparing the neurobiological effect of salt intake with modern drugs such as opiates and cocaine.

By consuming salt, the same gene patterns are activated in the brain as they are in drug use, report Wolfgang Liedtke from Duke University in North Carolina and his colleague Derek Denton from the University of Melbourne in Australia in the current issue of the journal „Proceedings of the National Academy of Sciences“. The researchers used mice to compare the effects of salt intake with the effect of drug use. They came to the conclusion that the urine instinct for salt intake apparently forms the basis of the effects of modern drugs in the brain.

Salt activates the same gene segments as drugs
The researchers from Duke University in North Carolina, USA and the University of Melbourne in Australia compared the neurobiological effect of drugs with that of essential sodium chloride (saline) on the basis of mice. They discovered that the same gene patterns are activated in the brain by salt, such as opiates and cocaine. The intake of salt is a vital instinct for humans and accordingly are the reactions in the brain, explain Wolfgang Liedtke and Derek Denton in the journal „Proceedings of the National Academy of Sciences“. According to Wolfgang Liedtke „The appetite for sodium salts is comparable to thirst for water. Similarly to quenching thirst, drinking a salty solution will bring you quick gratification.“ According to the researchers, modern drugs such as cocaine and opiates are based on these already existing mechanisms and thus generate a corresponding addiction or the urge for satisfaction, explained Liedtke and Denton. According to the researchers, some scientists have previously suspected, „that drug addiction could use circuits of old instincts“. With the current study, it was now possible to prove, „that a classic instinct, the hunger for salt, provides the neural organization, which is secondarily used by the addiction to opiates and cocaine“, the US-Australian researchers emphasized the importance of their work.

Reward system in the brain plays a key role
The neurobiologists were able to prove this with the help of a study in mice, which had a significantly increased salt requirement due to their extremely low-salt diet. In the genetic analysis, the researchers found that the craving for salt in the brain of the mice activated certain hypothalamic gene patterns that play a key role in drug addicts. Because the hypothalamus located in the midbrain not only controls the balance of energy, water and salts, but is also the seat of the body's reward system, which is stimulated both in salt intake and drug use. The researchers were able to show that the same genetic patterns are activated in the case of a salt deficit as in the case of addiction to opiates or cocaine. The activated genes also help make certain areas of the hypothalamus more sensitive to the effects of dopamine, the US-Australian scientists said. Dopamine, according to the experts as a messenger in the brain responsible for the feeling of satisfaction and is a crucial factor in the addiction and reward system of the brain.

New perspectives in addiction understanding
In their study, the researchers also investigated what effects can be achieved by inhibiting the activated gene segments. They discovered that in this way the salt instinct was suppressed. „We were surprised to see that blockade of addictive circuitry also severely affected sodium appetite“, emphasized Wolfgang Liedtke. The researchers were convinced that their results, on the one hand, provide a new perspective on the understanding of addiction and, on the other hand, conclusions about the consequences of too high-salt diets. (Fp)

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Less salt prevents heart disease

Picture credits: berwis