This vector delivers the channelrhodopsin-2 variant ChR2(H134R) under the neuron-specific human synapsin promoter, fused to enhanced yellow fluorescent protein for direct visualization of transduced cells. It is designed for light-gated depolarization of neurons in vivo and in vitro. The H134R substitution slows channel closing and raises the steady-state current relative to wild-type ChR2, giving more reliable spiking under sustained illumination. Peak activation sits near 470 nm, so standard blue LEDs and fiber-optic setups apply.