An international team of researchers has developed a therapy based on the GnRH protein that has improved the cognitive functions of a small group of patients with Down syndrome. The study, whose results have been published in Science, has been led by the University of Lille (France) and the University Hospital of Lausanne (Switzerland), and has had the participation of the University of Córdoba (UCO) and the Institute of August Pi i Sunyer Biomedical Research (Idibaps). Down syndrome, which affects one in 800 people, is the leading cause of intellectual disability and causes various clinical manifestations, including impaired cognitive ability. With age, 77% of sufferers experience symptoms similar to those of Alzheimer’s disease. People with this syndrome suffer from the gradual loss of olfactory capacity —typical of neurodegenerative diseases— and possible deficits in sexual maturation in the case of males. Gonadotropin-releasing hormone (GnRH) is an essential protein in reproductive function, “the signal with which the brain controls the reproductive system,” explains study co-author Manuel Tena-Sempere, and is used to improve fertility. At the Neuroscience and Cognition Laboratory in Lille, researchers discovered that in mouse models of Down syndrome this protein does not function properly, which contributes to the cognitive impairment associated with this syndrome. The researchers showed that activating GnRH neurons normalized the system and improved both functions.