Scientists Say: Optogenetics | Science News for Students

Scientists Say: Optogenetics

This is a technique that scientists use to control cells with light
Apr 29, 2019 — 6:30 am EST
an illustration of light hitting a nerve cell

This illustration shows an example of optogenetics. The blue light shining on this neuron activates channels in the brain cell. This can make the cell more or less active.

Ed Boyden and Massachusetts Institute of Technology McGovern Institute

Optogenetics (noun, “OP-toe-gen-EH-ticks”)

Optogenetics is a technique that can control a cell’s activity with light. It uses a molecule called channelrhodopsin (CHAN-el-roh-DOHP-sin). This molecule is found naturally in algae. It sits in a cell membrane. There, it acts like a gate, letting charged particles in or out. That rush of particles can make a cell pass messages to other cells. A channelrhodopsin opens in response to light. It can turn a cell’s activity up when the light turns on. In algae, the channel serves as a way to sense light.

Scientists can insert the genetic instructions for a channelrhodopsin into a cell they want to control. The cell then makes the channelrhodopsin molecule. It then inserts it into its own cell membrane.  When scientists shine a light nearby, the channelrhodopsin opens. That lets particles rush in or out.

Scientists now use optogenetics to control how cells function in the brains of mice, rats and monkeys. This helps the researchers better understand how the cells work. Scientists have been able to use this technique to show how the brain controls hunger. It has also let them learn how the tongue tastes the “flavor” of water.

In a sentence

Scientists are also trying optogenetics in other organs — such as the heart.

This video helps to explain how optogenetics works.
Neuro Transmissions/YouTube

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Power Words

(more about Power Words)

activate     (in biology) To turn on, as with a gene or chemical reaction.

algae     Single-celled organisms, once considered plants (they aren’t). As aquatic organisms, they grow in water. Like green plants, they depend on sunlight to make their food.

cell     The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells. Most organisms, such as yeasts, molds, bacteria and some algae, are composed of only one cell.

cell membrane     A structure that separates the inside of a cell from the outside of it. Some particles are permitted to pass through the membrane.

channelrhodopsin  Any one of a group of molecules that open in response to light, originally found in algae. Scientists insert the instructions for these molecules into other cells such as brain cells, and then can use light to control their activity.

genetic     Having to do with chromosomes, DNA and the genes contained within DNA. The field of science dealing with these biological instructions is known as genetics. People who work in this field are geneticists.

membrane     A barrier which blocks the passage (or flow through) of some materials depending on their size or other features. Membranes are an integral part of filtration systems. Many serve that same function as the outer covering of cells or organs of a body.

molecule     An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2), but water is made of two hydrogen atoms and one oxygen atom (H2O).

optogenetics     A technique that uses light to better understand genes and cells in the nervous system, especially the brain. Recent research is using the technology to study other types of cells and tissues too.

organ     (in biology) Various parts of an organism that perform one or more particular functions. For instance, an ovary is an organ that makes eggs, the brain is an organ that makes sense of nerve signals and a plant’s roots are organs that take in nutrients and moisture.