Methods Development for Expression of Luminopsin 3 in the Neurons of C. elegans
Optogenetics has emerged as a novel method for investigating neural circuits. This method uses light activated or light emitting molecules that have been integrated in neurons to either stimulate neuron firing or to report neural activity. In this project, I am using an optogenetic protein called luminopsin 3 to stimulate a subset of neurons in the model organism C. elegans. The crux of luminopsin 3 (LMO3) is a light-activated ion channel called channelrhodopsin. When channelrhodopsin is stimulated with blue light, it propagates action potentials in neurons, making it a valuable optogenetic tool. The LMO3 protein can also act in the absence of external light when a chemical cofactor, called coelantrazine (CTZ), is present. This makes LMO3 a chemical genetic tool as well. While channelrhodopsin has been integrated into C. elegans neurons before, to the best of our knowledge, a dual optogenetic and chemical genetic approach in these animals has not yet been described. Furthermore, no literature exists for the application or introduction of CTZ in C. elegans. Therefore, we are developing a method for the expression of LMO3 in the GABAergic neurons of the model organism C. elegans. Here, we report a transgenic strain of C. elegans containing the construct, preliminary data for the characterization of the construct, and a novel approach for the use of CTZ in a C. elegans system. We hope this tool will open up new pathways for research on effects of short term, chronic, and temporal effects of neuron activation on axon regeneration and neuroplasticity.