The specificity of temporal coding requires highly refined technology to create informative, reliable experimental data. In 2009, advances made in [[optogenetics]] allowed neurologists to control spikes in individual neurons, offering electrical and spatial single-cell resolution. For example, a [[channelrhodopsin]] in pond scum opens when it senses blue light, depolarizingdepolarizes the cell, and producingproduces a spike. When blue light is not sensed, the channel closes, and the neuron ceases to spike. The pattern of the spikes matches the pattern of the blue light stimuli. By inserting channelrhodopsin DNA into mouse DNA, researchers can control spikes and therefore certain behaviors of the mouse (i.e., making the mouse turn left).<ref> Karl Diesseroth, Lecture. “Personal Growth Series: Karl Diesseroth on Cracking the Neural Code.” Google Tech Talks. November 21, 2008. http://www.youtube.com/watch?v=5SLdSbp6VjM</ref> Researchers, through optogenetics, have the tools to effect different temporal codes in a neuron while maintaining the same mean firing rate, and thereby can test whether or not temporal coding occurs in specific neural circuits. <ref>Han X, Qian X, Stern P, Chuong AS, Boyden ES. “Informational lesions: optical perturbations of spike timing and neural synchrony via microbial opsin gene fusions.” Cambridge, MA: MIT Media Lad, 2009. PubMed.</ref>
