title: Making Sense of Optogenetics.
abstract: This review, one of a series of articles, tries to make sense of optogenetics, a recently developed technology that can be used to control the activity of genetically-defined neurons with light. Cells are first genetically engineered to express a light-sensitive opsin, which is typically an ion channel, pump, or G protein-coupled receptor. When engineered cells are then illuminated with light of the correct frequency, opsin-bound retinal undergoes a conformational change that leads to channel opening or pump activation, cell depolarization or hyperpolarization, and neural activation or silencing. Since the advent of optogenetics, many different opsin variants have been discovered or engineered, and it is now possible to stimulate or inhibit neuronal activity or intracellular signaling pathways on fast or slow timescales with a variety of different wavelengths of light. Optogenetics has been successfully employed to enhance our understanding of the neural circuit dysfunction underlying mood disorders, addiction, and Parkinson's disease, and has enabled us to achieve a better understanding of the neural circuits mediating normal behavior. It has revolutionized the field of neuroscience, and has enabled a new generation of experiments that probe the causal roles of specific neural circuit components.
authors.affiliation: Department of Neurobiology and Behavior, Cornell University, Ithaca, NY (Mr Guru and Post, Ms Ho, and Dr Warden).
authors.forename: Akash
authors.initials: A
authors.lastname: Guru
authors.affiliation: Department of Neurobiology and Behavior, Cornell University, Ithaca, NY (Mr Guru and Post, Ms Ho, and Dr Warden).
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Post
authors.affiliation: Department of Neurobiology and Behavior, Cornell University, Ithaca, NY (Mr Guru and Post, Ms Ho, and Dr Warden).
authors.forename: Yi-Yun
authors.initials: YY
authors.lastname: Ho
authors.affiliation: Department of Neurobiology and Behavior, Cornell University, Ithaca, NY (Mr Guru and Post, Ms Ho, and Dr Warden). mrwarden@cornell.edu.
authors.forename: Melissa R
authors.initials: MR
authors.lastname: Warden
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D062308:Optogenetics / Q000379:methods
keywords: ChR2; NpHR; OptoXR; channelrhodopsin-2; halorhodopsin; optogenetics