Mentor: Christian Zemlin, Associate Professor of Surgery, Division of Cardiothoracic Surgery, Director of the Cardiothoracic Surgery Research Lab The Zemlin laboratory studies cardiac arrhythmia mechanisms, particularly the mechanism of atrial fibrillation. We use both optical mapping with voltage-sensitive fluorescent probes and extracellular electrodes to monitor cardiac electrical activity. We are also interested in the surgical treatment of cardiac arrhythmias, and we are developing a new ablation modality for cardiac tissue based on electroporation with nanosecond pulsed electric fields. Projects: One of our current projects that would be interesting for undergraduate students to participate in is sonogenetics. In this project, we study rat hearts that have been transfected with mechanosensitive ion channels, in particular, how sensitive these hearts are to stimulation with ultrasound. We have an existing optical mapping set up to monitor the electrical activity of rat hearts, which needs to be extended in several ways: 1) We need to extend our setup to allow for the placement and manipulation of different ultrasound probes; 2) We need to perform optical mapping experiments in which we use the ultrasound probes to stimulate the genetically modified hearts; 3) the movies that are recorded during or stimulation attempts need to be processed and evaluated to determine the efficacy of ultrasound stimulation. All these tasks offer great opportunities for undergraduate student participation.