AAV with eSYN promoter driven hChR2(C128S)-TdTomato

This AAV expresses hChR2(C128S)-TdTomato driven by a neuron eSYN promoter.

The eSYN is a hybrid promoter consisting of a 0.4Kb CMV enhancer (E) and the 0.45Kb human Synapsin I promoter fragment (hSYN1). eSYN hybrid promoter gives about 2-4 fold higher expression than that of the parental hSYN1 promoter. However, the neuronal specificity of eSYN is slightly decreased, compared to that of the parental hSYN1 promoter.

hChR2 is a humanized version of ChR2 for mammalian expression. Wild-type ChR2, as well as a few of its mutations, provides the fastest excitation of the channelrhodopsins offered, and is widely used in in optogenetics techniques in neuroscience. Mutations at C128 (C128A, C128S, C128T) can extend depolarization up to seconds or even minutes; they are sometimes referred to as step-function opsins or SFOs. hChR2(C128S) provides for a 1.7-minute open-state lifetime and shows moderate expression in the hippocampal neurons and Pichia pastoris. Like C128T, it is inactivated at strong light.