-Guilty as charged: Graphene meets liquid droplets -
Electric Potential at the Interface of Membraneless Organelles Gauged by Graphene
Brain communication critically relies on the secretion of messenger molecules upon the arrival of an electrical signal. These messenger molecules are packed in small sacs called synaptic vesicles. Hundreds of synaptic vesicles accumulate at the contact points between neurons. Recently, these cohorts of SVs were shown to form dynamic liquid-like compartments at the synapse, which is mediated by some of the most highly abundant neuronal proteins called synapsins. In an exciting fusion of expertise, physicist Aleksandar Matkovic from the University Leoben and neuroscientist Dragomir Milovanovic from the German Center for Neurodegenerative Diseases in Berlin discovered that liquid droplets of synapsins and synaptic vesicles are able to harbor electrical potential at their interface. In a recently published issue of Nano Letters, featured on a cover page, the authors used graphene-based sensors to demonstrate the accumulation of electric charge. This opens an entirely new series of questions, suggesting that an ion gradient within the cytosol of the synapse might be a new layer of regulating neuronal communication.