1. Department of Biological Sciences, Bridgewater State University, Bridgewater, Massachusetts, USA
2. Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
3. Department of Mathematics and Statistics, Boston University, Boston, Massachusetts, USA
4. Chapel Hill, Biological and Biomedical Sciences Program, University of North Carolina, Chapel Hill, North Carolina, USA
5. Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
6. Center for Systems Neurogenetics of Addiction, The Jackson Laboratory, Bar Harbor, Maine, USA