Light switch turns paralysis on and off

As described in a paper in the Journal of the American Chemical Society (2009, 131 (46), pp 16644–16645), Neil Branda and colleagues at Simon Fraser University (Burnaby, BC, Canada) have demonstrated an on-off "switch" that, when exposed to ultraviolet light, holds animals in paralysis even when the light is turned off. Exposure to ordinary light, though, flips the switch and turns the paralysis off.

Click to Enlarge

Transparent C. elegans worms, raised on a diet of light-sensitive dithienylethene, turned blue and became paralyzed when exposed to light of 300 to 400 nm wavelength. When exposed to visible light (wavelengths greater than 490 nm), the dithienylethene became colorless again and the paralysis ended. Many of the worms lived through the cycle, and scientists say the photoreactions tend to proceed with a high degree of efficiency and with minimal degradation. While it remains unclear just how the switch causes paralysis, the study demonstrates potential for photoswitches in photodynamic therapy and for other applications in medicine and research.

Use of the reversible photoreactions of diarylethenes for applications such as in vivo drug delivery or for unmasking therapeutic agents demand consideration of issues such as whether the photoresponsive systems can be absorbed by a living organism, whether they retain their reversible photoactivity, and if the two forms of molecular switch have unique effects on the function of the living organism.

More Brand Name Current Issue Articles
More Brand Name Archives Issue Articles

Get All the BioOptics World News Delivered to Your Inbox

Subscribe to BioOptics World Magazine or email newsletter today at no cost and receive the latest news and information.

 Subscribe Now
Related Articles

OCT imaging improves percutaneous coronary intervention, study finds

OCT can visualize coronary arteries in patients undergoing percutaneous coronary intervention, leading to improved outcomes.

Single-photon counting camera for FLIM by Photonis

The Imaging Photon Camera has utility in fast imaging under low-light conditions, such as in fluorescence lifetime imaging microscopy.

FDA authorizes emergency use of Zika virus molecular detection assay

The xMAP MultiFLEX Zika RNA assay combines optofluidics and digital signal processing to detect Zika virus in vitro.

'Lab on a stick' test optically and rapidly detects antibiotic resistance

A point-of-care test, based on the dipstick method, can rapidly detect bacterial resistance to antibiotics in urine.


Neuro15 exhibitors meet exacting demands: Part 2

Increasingly, neuroscientists are working with researchers in disciplines such as chemistry and p...

Why be free?

A successful career contributed to keeping OpticalRayTracer—an optical design software program—fr...

LASER Munich 2015 is bio-bent

LASER World of Photonics 2015 included the European Conferences on Biomedical Optics among its si...

White Papers

Understanding Optical Filters

Optical filters can be used to attenuate or enhance an image, transmit or reflect specific wavele...

How can I find the right digital camera for my microscopy application?

Nowadays, image processing is found in a wide range of optical microscopy applications. Examples ...



Twitter- BioOptics World

Copyright © 2007-2016. PennWell Corporation, Tulsa, OK. All Rights Reserved.PRIVACY POLICY | TERMS AND CONDITIONS