A group of researchers has discovered that ghrelin, already defined as “the hunger hormone” because it is responsible for transmitting hunger signals from the intestine to the brain, can improve memory.
This substance, produced in the stomach, binds to particular receptors of the vagus nerve, a nerve that connects the intestine to the brain. According to Scott Kanoski, senior author of the study, ghrelin helps the vagus nerve promote memory, at least in the laboratory mice on which the experiments were conducted.
By blocking ghrelin signaling in rats using a method called RNA interference, the researchers found that mice had worse results in episodic memory tests, tests that involve having to remember when something happened or where it is. In the case of these experiments, the rats had to remember where an object was located in a specific location.
Furthermore, when the ghrelin signal was interrupted through the vagus nerve, rodents tended to eat more frequently but consumed smaller amounts with each meal.
According to the researchers, this characteristic would also be related to the problem of reduced memory as “deciding to eat or not to eat is influenced by the memory of the previous meal,” as specified by Elizabeth Davis, the lead author of the study.
These findings could prove useful for improving memory capacity in humans.