I.R.C.C.S. Neuromed researchers, in partnership with Sapienza University of Rome and other worldwide institutes, discovered that a specific nerve receptor, mGlu3, can guard against the progression of Parkinson's disease. The study, published in the prominent journal npj Parkinson's Disease, proposes a novel strategy to more effective therapy interventions. The mGlu3 receptor, which belongs to the Metabotropic Glutamate Receptor family, has been examined in both animal models and human patients. For the former, the researchers compared so-called "knockout" mice, which are genetically lacking this receptor, to mice in which the receptor is typically functional. All animals were subjected to a specific chemical, MPTP, which mimics several physiological characteristics of Parkinson's. The results of the experiment indicated that the animals lacking mGlu3 exhibited a more severe level of neuronal damage and brain inflammation than the normal mice. In the subsequent analysis, variants of the gene encoding mGlu3 (GRM3) were compared in over 700 Parkinson's patients to 800 participants in the Moli-sani Epidemiological Project who were not affected by the disease. Some of the genetic variants were found to be associated with more severe symptoms in patients, both motor and cognitive. In tests of brain plasticity (which measure the brain's ability to adapt), patients carrying these variants showed reduced responses. In healthy participants, however, no significant alterations were observed, suggesting that the variants exert their negative effects primarily in the presence of the disease.