Laura A Ewell1, Stefan Leutgeb2. 1. Neurobiology Section and Center for Neural Circuits and Behavior, Division of Biological Sciences, University of California, San Diego, La Jolla, California, USA. 2. 1] Neurobiology Section and Center for Neural Circuits and Behavior, Division of Biological Sciences, University of California, San Diego, La Jolla, California, USA [2] Kavli Institute for Brain and Mind, University of California, San Diego, La Jolla, California, USA.