TY - JOUR T1 - Aberrant Cortical Activity in Multiple GCaMP6-Expressing Transgenic Mouse Lines JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0207-17.2017 VL - 4 IS - 5 SP - ENEURO.0207-17.2017 AU - Nicholas A. Steinmetz AU - Christina Buetfering AU - Jerome Lecoq AU - Christian R. Lee AU - Andrew J. Peters AU - Elina A. K. Jacobs AU - Philip Coen AU - Douglas R. Ollerenshaw AU - Matthew T. Valley AU - Saskia E. J. de Vries AU - Marina Garrett AU - Jun Zhuang AU - Peter A. Groblewski AU - Sahar Manavi AU - Jesse Miles AU - Casey White AU - Eric Lee AU - Fiona Griffin AU - Joshua D. Larkin AU - Kate Roll AU - Sissy Cross AU - Thuyanh V. Nguyen AU - Rachael Larsen AU - Julie Pendergraft AU - Tanya Daigle AU - Bosiljka Tasic AU - Carol L. Thompson AU - Jack Waters AU - Shawn Olsen AU - David J. Margolis AU - Hongkui Zeng AU - Michael Hausser AU - Matteo Carandini AU - Kenneth D. Harris Y1 - 2017/09/01 UR - http://www.eneuro.org/content/4/5/ENEURO.0207-17.2017.abstract N2 - Transgenic mouse lines are invaluable tools for neuroscience but, as with any technique, care must be taken to ensure that the tool itself does not unduly affect the system under study. Here we report aberrant electrical activity, similar to interictal spikes, and accompanying fluorescence events in some genotypes of transgenic mice expressing GCaMP6 genetically encoded calcium sensors. These epileptiform events have been observed particularly, but not exclusively, in mice with Emx1-Cre and Ai93 transgenes, of either sex, across multiple laboratories. The events occur at >0.1 Hz, are very large in amplitude (>1.0 mV local field potentials, >10% df/f widefield imaging signals), and typically cover large regions of cortex. Many properties of neuronal responses and behavior seem normal despite these events, although rare subjects exhibit overt generalized seizures. The underlying mechanisms of this phenomenon remain unclear, but we speculate about possible causes on the basis of diverse observations. We encourage researchers to be aware of these activity patterns while interpreting neuronal recordings from affected mouse lines and when considering which lines to study. ER -