One epigenetic factor as well as one organic anion transporter (OAT1), whose function in the nervous system was hitherto unknown, contribute to the development of chronic pain. The underlying molecular mechanism was identified by a team of researchers led by Dr. Daniela Mauceri at the Interdisciplinary Center for Neurosciences (IZN) of Heidelberg University. Using mouse models, the researchers demonstrated that the epigenetic factor, known as HDAC4, influences the expression of genes in neuronal cells involved in the processing of pain. The Heidelberg experiments also revealed that the transporter OAT1 regulates pain sensitivity in the spinal cord. The team hopes their findings will pave the way to new approaches for the treatment of chronic pain.