Reagent Type

Plasmid DNA for packaging AAV; Recombinant AAV; conditional knock-in mouse 

Description of what it is used for

Circuit analysis and manipulation tool: neuronal activation/inhibition

Description of its capabilities

Non-invasive activation across the brain of all cells expressing the tool; allows dual chemo-and optogenetic activation of the same cell 

Location (Research Facility) 

Plasmid DNA [Addgene]; AAVs, conditional mouse [Bioluminescent Optogenetics Lab, CMU]

Link to a User Manual 

https://www.bioluminescencehub.org/LMO3 [E-Z Guide to LMO3]

Other relevant documents related to the tool

https://www.biorxiv.org/content/10.1101/710194v1 

https://www.cell.com/iscience/fulltext/S2589-0042(21)00125-5

Type of research that was enhanced by its use 

Determining role of neural activity during postnatal development in shaping adult behavior and underlying circuits; restoring locomotor function after severe spinal cord injury

R26-LSL-LMO3 mice (LSL-LMO3)
R26-LSL-LMO3 mice (also called LSL-LMO3) contain the bimodal (chemo- and optogenetic) actuator LMO3. Specifically, LMO3 contains an excitatory channelrhodopsin fused to a Gaussia luciferase variant, downstream of a floxed STOP cassette, inserted into the Gt(ROSA)26Sor locus. LMO3 allows for both standard optogenetic (physical light) and chemogenetic (application of luciferase substrate coelenterazine) activation. Mice that are homozygous for this floxed allele are viable and fertile. In the absence of Cre, LMO3 expression is prevented by the STOP cassette. After removal of the loxP-flanked STOP cassette via cre-mediated recombination, LMO3 is expressed, enabling the excitation of specific neuronal populations. Learn more about the tool.