Activation of the receptor for the appetite-stimulating hormone ghrelin has been found to enhance learning and memory by researchers from the University of Coimbra in Portugal and the Universidad Autónoma de Madrid in Spain in a study that was published in the Dec. 23, 2013, edition of the journal Proceedings of the National Academy of Sciences.
When a person is hungry, the stomach releases the hormone ghrelin. Ghrelin is known to activate appetite through the release of the ghrelin receptor growth hormone secretagogue type 1a (GHS-R1a) in the hypothalamus and pituitary regions of the brain.
The researchers found that GHS-R1a activates parts of the hippocampus that are involved with the formation and storage of memories. GHS-R1a was also found to produce a chain of chemical events that activates synapse function in the brain that enhances synaptic plasticity that is thought to underlie learning and memory.
The researchers conclude that learning is enhanced by periods of fasting. The results were proven with primates and in mouse studies.
Similar reactions in humans are most probable because the brain chemistry in mice, primates, and humans as well as the physical brain structure is the same.
The enhanced learning effects were found to cease when the test animals had a meal.
This research may account for part of the differences seen in the performance of overweight and obese children in learning in school.