Scientists have synthesized molecules which optically control the function of nerve cells that mediate perception of pain

Munich: A thoughtless brush with a hotplate and an encounter with the fiery taste of a vindaloo curry are both painful experiences. These apparently very different stimuli provoke the same burning sensation because they both activate the same cell-surface receptor, TPRV1. TRPV1 is ultimately responsible for the perception of the pain evoked both by high temperatures and by the chemical irritants found in many spicy foods. The receptor is mainly expressed by nerve fibers in sensory epithelia, and it responds not only to high temperatures and compounds present in chilis and other types of pepper, but also to electrical potentials, spider toxins and acids. “One stimulus it does not respond to is light,” says Dirk Trauner, Professor of Chemical Biology and Genetics at LMU. But recent work by his research team has now changed that.

Muscles engineered to be photosensitive could lead to treatments for paralysis

Nature: Scientists have genetically engineered muscles to move in response to pulses of light. The technique, demonstrated on vocal cords removed from mice, is reported on 2 June in Nature Communications. Researchers say that it could probe how muscles function — and might eventually help to treat people who have a paralysis that interferes with speech and breathing. The work relies on a method called optogenetics, which can make cells that usually respond to electrical signals also react to light. The approach alters mammalian cells by inserting a gene for a protein such as channelrhodopsin, which in its natural setting allows blue-green algae to swim towards or away from light.

Researchers find “lost” memories

MIT: Memories that have been “lost” as a result of amnesia can be recalled by activating brain cells with light. In a paper published today in the journal Science, researchers at MIT reveal that they were able to reactivate memories that could not otherwise be retrieved, using a technology known as optogenetics. The finding answers a fiercely debated question in neuroscience as to the nature of amnesia, according to Susumu Tonegawa, the Picower Professor in MIT’s Department of Biology and director of the RIKEN-MIT Center at the Picower Institute for Learning and Memory, who directed the research by lead authors Tomas Ryan, Dheeraj Roy, and Michelle Pignatelli.