Channelrhodopsins are ion channels that are directly opened by light. They therefore may be very useful molecules, enabling the use of light to control intracellular acidity, calcium influx, and electrical excitability.

Two channelrhodopsins are currently known: Channelrhodopsin-1 is a light-activated hydrogen ion channel, and Channelrhodopsin-2 is a light-activated cation channel. Structurally, channelrhodopsins are seven-transmembrane proteins like rhodopsin, and contains the light-isomerizable vitamin A derivative all-trans-retinal. However, whereas most opsins are G-protein coupled receptors that open other ion channels indirectly via messengers, channelrhodopsins contain not only the light-activatable transduction mechanism, but the channel pore itself. This makes cellular depolarization extremely fast, robust, and useful for bioengineering and neuroscience applications, including photostimulation. General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Another, unrelated ion channeling process is part of ion implantation. ... Channelrhodopsin-2 is a light-activated cation channel. ... Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific setting, electromagnetic radiation of any wavelength. ... A rhodopsin molecule (yellow) in the cell membrane (blue). ... Retinol, the dietary form of vitamin A, is a fat-soluble, antioxidant vitamin important in vision and bone growth. ... The Retinenes (Retinene1 and Retinene2) are chemical derivatives of the dietary supplement vitamin A (see retinol) formed through oxidation reactions. ... G-proteins, short for guanine nucleotide binding proteins, are a family of proteins involved in second messenger cascades. ... Receptor may refer to: In telecommunication, a receiver. ... Another, unrelated ion channeling process is part of ion implantation. ... Photostimulation is the use of light to artificially activate biological compounds, cells, or even whole organisms. ...

External links

• Using channelrhodopsin to control neural activity