Among many different functions, proteins serve as the molecular machines of the cell. They transport materials, cleave products, or transmit signals – and for a long time, they have been a main focus of attention in molecular biology research. In the last two decades, however, another class of critically important molecules has emerged: small RNA molecules, including micro-RNAs. It is now well established that micro-RNAs play a key role in the regulation of cell function. "A micro-RNA regulates the production of an estimated 300-400 proteins. This class of molecules can be regarded as a switch that coordinates the transition of cells from one state to another," explains Professor André Fischer, scientist at the German Center for Neurodegenerative Diseases (DZNE) and Speaker of the DZNE site Göttingen. He and his team have identified a micro-RNA that regulates the learning processes and probably plays a central role in Alzheimer's disease. The researchers have shown that there is too much of a micro-RNA called "miRNA 34c" in mouse models of Alzheimer's disease, and decreasing the level of miRNA 34c in these mice can restore their learning ability. The scientists have identified a new target molecule that might be important for diagnosis and treatment of Alzheimer's disease. The studies were carried out in collaboration with scientists at the European Neuroscience Institute Göttingen, the Göttingen University, and the DZNE site in Munich, and with researchers from Switzerland, USA and Brazil. The results were published online on September 23, 2011, in The EMBO Journal.Login Or Register To Read Full Story