AAV with eSYN promoter driven hChR2(H134R)-EYFP

This AAV expresses hChR2(H134R)-EYFP 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.

Channelrhodopsins are light-gated ion channels that exist naturally in microalgae. hChR2 is a humanized version of ChR2 for mammalian expression. It is maximally excited by 470 nm light. The wild-type, as well as a few mutations, provide the fastest excitation of the channelrhodopsins offered, and are widely used in optogenetics techniques in neuroscience. Due to delayed channel closure, hChR2(H134R) is a gain-of-function mutation that produces larger photocurrents than wild-type hChR2, but slows down channel kinetics.