In a new study, a group of Portuguese scientists found out how the hunger hormone called ghrelin at the molecular level affects the brain, improving learning ability and memory. The findings of the Portuguese are published in the latest issue of the journal ProceedingsoftheNationalAcademyofSciences.
“Our results reveal a mechanism that can explain the improvement of mental abilities with the help of ghrelin and find that there is a close relationship between energy metabolism and learning,” says Ana Carvalho and her colleague from Coimbra University (Portugal).
Scientists in laboratory rats have investigated how activation of ghrelin receptors affects hippocampal tissue. As a result, they found that thanks to this hormone, AMPA receptor signaling is increased, allowing nerve cells to rapidly exchange information between synapses. Researchers also injected ghrelin into the rodents’ brains and made sure that their memory capacity improved.
Ghrelin hormone is produced by the cells of the stomach when it is not full of food. It, in turn, binds to receptors in the brain pituitary and hypothalamus and stimulates the production of growth hormone, causes hunger and reduces the amount of fat burned. But receptors for the hormone of hunger are also found in other parts of the brain, for example, in the hippocampus.
From earlier studies, it is known that in this part of the brain, the action of ghrelin helps to improve learning and memory. On the contrary, a diet with a high content of glucose and fats, at which the level of the ghrelin hormone in the body is low, impairs memory function and reduces synaptic plasticity, the so-called ability of nerve cells to change the strength of connections between themselves, due to which the brain is able to absorb new information and skills.