Recent advances in optogenetics have enabled simultaneous optical perturbation and optical readout of membrane potential in diverse cell types. Here, we develop and characterize a Cre-dependent transgenic Optopatch2 mouse line that we call Floxopatch. The animals expressed a blue-shifted channelrhodopsin, CheRiff, and a near infrared Archaerhodopsin-derived voltage indicator, QuasAr2, via targeted knock-in at the rosa26 locus. In Optopatch-expressing animals, we tested for overall health, genetically targeted expression, and function of the optogenetic components. In offspring of Floxopatch mice crossed with a variety of Cre driver lines, we observed spontaneous and optically evoked activity in vitro in acute brain slices and in vivo in somatosensory ganglia. Cell-type-specific expression allowed classification and characterization of neuronal subtypes based on their firing patterns. The Floxopatch mouse line is a useful tool for fast and sensitive characterization of neural activity in genetically specified cell types in intact tissue.
Bibliographical noteFunding Information:
This work was supported by the Howard Hughes Medical Institute, the Allen Institute for Brain Science, and GlaxoSmithKline (Bioelectronic Medicines Initiative Grant). A.E.C. is supported by National Institutes of Health (NIH) Grant 1-R01-EB012498. Y.A. is supported by a long-term fellowship of the Human Frontier Science Program. E.W. is supported by NIH Grants F30CA177170 and T32GM007753. S. Liberles is supported by NIH Grant DK103703. We thank Vaibhav Joshi and Melinda Lee for technical assistance. We thank Qiufu Ma, Xinzhong Dong, Rohini Kuner, Venkatesh Murthy, and Paola Arlotta for scientific discussions and for sharing Cre driver mouse lines; Corey Smith, Stephen Lewis, and Paulina Getsy for training and assistance; the Harvard University Genome Modification Facility for technical support in generating transgenic mice; and the Harvard Center for Brain Sciences for providing confocal imaging facilities.
© 2016 the authors.
- Transgenic mice
- Voltage imaging