In addition to regulating blood sugar levels, insulin plays a critical role in modulating the activity of neurons involved in learning and memory , according to a new work published in the journal Neuron . "People often think that insulin regulation disorders can only cause diabetes, but many cognitive and behavioral defects, such as depression or dementia, are also associated with metabolic syndromes," says Yun Zhang, a biologist at the University of Harvard and responsible for the study.
To study this link, Zhang and his colleagues turned their attention to the transparent worm Caenorhabditis elegans . Using genetic engineering techniques, they eliminated its ability to create insolin-like compounds. The "mutant" worms thus obtained were then tested to see if they were able to learn to avoid eating a bacterium that infects them. And the scientists discovered that those who, unlike unmodified worms, not only could not synthesize insulin but also had lost the ability to learn . Interestingly, it was not only due to the absence of this hormone but to a complex network of molecules and peptides similar to insulin that “act together and coordinate their signals to regulate learning and memory, so that if the way is changed in which they interact also modifies the way we learn ”, points out Zhang. Understanding these molecular pathways and neural circuits could help treat cognitive disorders, including dementia, in the future.
