Igs7^{tm203(tetO-sChroME*/GCaMP7s,CAG-mRuby3,-tTA2)Tasic}

The targeting vector has a Tet response element (tetO), loxP-STOP-loxP cassette and a sChroME*/GCaMP7s-WPRE sequence that is followed by a CAG promoter, Lox2272-STOP-Lox2272 cassette, mRuby3, and IRES-tTA2-WPRE sequence - all inserted into the T1 TIGRE locus (an intergenic region on chromosome 9 [between AB124611 and Carm1] determined to have low basal transcriptional activity and allow high cre and/or Tet inducibility). sChroME*/GCaMP7s is the result of a sChroME* coupled to the fluorescent reporter GCaMP7s (an ultrasensitive EGFP fluorescent calcium detector of neuronal activity with slow decay and response kinetics). sChroME is a soma-targeted (ST) ultrafast and highly potent opsin with 3-5x larger photocurrents than opsins commonly used for multiphoton optogenetics. Of note, the Ai203 allele was designed with an IRES upstream of the tTA2 to reduce/eliminate leakiness in the absence of cre recombinase. (J:339333)