Changing our brains can keep us away from certain foods for life after a bad meal

Bad experiences with food, like a questionable curry that makes us sick for days on end, trigger a change in our brain that means we never want to eat it again, study finds.

British researchers have successfully reproduced the effect of a negative experiment on eating behavior, using sugar-loving snails as laboratory models.

They used “ aversive training, ” which consisted of patting the snails on the head when the sugar appeared, as an indicator of food poisoning in humans, during filming.

Aversive workout flipped an appetite suppressant switch which meant the snails refused to feed on sugar even when hungry.

Experts believe something similar is happening, leading to a “persistent physiological change” that is specific to a certain food for the rest of our lives.

“ In fact, a switch has been flipped in the brain, which means the snail no longer eats the sugar when presented to it, because the sugar now suppresses rather than activates feeding, ” said study author Dr Ildiko Kemenes at the University of Sussex.

Snails love sugar and usually start eating it as soon as it is presented to them, just like humans when they spot sugary treats in the kitchen.

“Snails provide us with a similar but exceptionally basic model of how the human brain works,” said Professor George Kemenes, also at the University of Sussex.

“ In our research, snail’s negative experience with sugar could be compared to consuming a bad curry on the go, which will keep us away from this dish in the future. ”

Despite their primitive appearance and reputation, there is a change in the brain of snails that actually prevents them from overeating.

This appetite suppressant switch (ASS) is controlled by a neuron – a type of highly excitable cell that transmits information to parts of the body via electrical signals.

“There is a neuron in the brain of the snail that normally suppresses the feeding circuit,” said Dr Ildiko Kemenes.

“This is important because the network tends to activate spontaneously, even in the absence of food.

“By removing the feeding circuit, it ensures that the snail doesn’t just eat anything and everything.

Researchers believe something similar is happening in the human brain, seen as a natural tactic to protect us from obesity (although it’s likely that some people’s appetite suppressants work better than others) .

Usually when food is present, this neuron in the snail brain is inhibited so that feeding can begin.

After the aversive training of the hungry snails, the researchers found that this neuron reversed its electrical response to sugar and became aroused instead of being inhibited by it.

This increased activity of the excited neuron essentially actuated SSA, suppressing the snails’ appetite.

More importantly, this effect has only been observed for sugar – which is why researchers compared it to the lasting psychological effects of humans eating a specific meal that makes them sick.

When the researchers presented the trained snails with a piece of cucumber instead, they found that the animal was still happy to eat it.

This showed that the gentle patting of the head during aversive training was associated only with the particular type of food that was present at the time.

“We believe that in a human brain, a similar change could occur when particular groups of neurons reverse their activity based on the negative association of a particular food,” said Professor George Kemenes. .

The research also found that when the neuron was completely removed from the trained snails, they would start eating sugar again.

“This suggests that the neuron is needed for the expression of learned behavior and for modifying the response to sugar,” said Dr. Ildiko Kemenes.

“However, we cannot rule out that the sensory pathway activated by sugar is also undergoing changes, so we don’t assume that this is all happening in the brain.”

The study was published in Current Biology.