from the bright-idea dept.
Optogenetics is a marvel of our age, enabling neuroscientists to turn brain cells on and off with pulses of light. But until now there's been an obvious difficulty: How do you deliver that light to brain cells that are tucked inside an animal's skull?
Today we get the best answer yet, from the Stanford lab of Ada Poon. She and her colleagues have invented a tiny, wireless LED device that can be fully implanted beneath the skin of a mouse. The device lets researchers turn on the light and stimulate neurons when the mouse is scampering around, behaving more or less normally. This system, described today in the journal Nature Methods, seems a big improvement over previous technology, which used wires or bulky head-mounted devices to activate the light switch.
Here's a quick optogenetics primer, in case you need it. The technique makes use of neurons that have been genetically altered to respond to light, often with the introduction of genes from a strain of green algae. Researchers can control which part of a mouse brain contains these light-sensitive neurons, and they can then study the function of that brain region by activating the neurons—essentially turning them on and off—while watching the animal's behavior. Using this method, scientists can learn about basic brain anatomy or study dysfunctions seen in human diseases.
Researchers have created a protein that breaks into two pieces when exposed to light:
Researchers at the University of Alberta have developed a new method of controlling biology at the cellular level using light. The tool -- called a photocleavable protein -- breaks into two pieces when exposed to light, allowing scientists to study and manipulate activity inside cells in new and different ways.
First, scientists use the photocleavable protein to link cellular proteins to inhibitors, preventing the cellular proteins from performing their usual function. This process is known as caging. "By shining light into the cell, we can cause the photocleavable protein to break, removing the inhibitor and uncaging the protein within the cell," said lead author Robert Campbell, professor in the Department of Chemistry. Once the protein is uncaged, it can start to perform its normal function inside the cell. The tool is relatively easy to use and widely applicable for other research that involves controlling processes inside a cell.
Optogenetic control with a photocleavable protein, PhoCl (DOI: 10.1038/nmeth.4222) (DX)
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