A team from the Florey Institute are also optimistic that the discovery could lead to treatments for other addictions that use the same pathways in the brain, such as heroin, morphine and other opiate-based painkillers.
Craig Smith, a neuroscientist at the Melbourne institute, said the brain's opioid system had long been known to be associated with the feeling of reward generated from eating food containing high salt content.
Salt cravings are among the reasons why it is difficult to say no to the question "want fries with that?”, and why the smell of sizzling bacon makes one’s mouth water.
Australians, on average, consume some three times more sodium than they need, with most of the salt coming from processed foods.
The researchers identified exactly where in the brain the salt cravings originate, as well as the mechanism at play
Using a process of elimination, they could discover the location of the "salt-seeking wiring" in the brain for the first time.
Three groups of mice were administered three different types of opioid-blockers and denied salt for two days until they were allowed to drink salty water on the third day.
The first two groups drank about 5% of their body weight in salty water in an hour, representing a high craving for the salt. But the third group, which were given opioid-blocker naloxonazine, drank just 2% of their body weight.
Dr Smith said the mice revealed eating salt engaged the opioid in the central amygdala region of the brain, the same part where positive and negative emotions are processed.
"It wasn't known until now that our natural opioids working in this emotional hotspot drove salt cravings," Smith told Fairfax Media.
"Switching off salt cravings would promote a healthier diet and food choices.
"Because at the moment you know the salad is healthy but you crave the junk food for the salt. It's tasty and it's in a lot of food. But we eat too much of it."