| RESEARCH HIGHLIGHTS |
merge at an angle, driven by the propensity to minimize the surface energy, and thus create ridges and grooves that spiral around the nanowire. “This selective etching is driven by a faster
etching rate at some defect locations on the silver nanowire,” says Wei. “Thus, we can
convert a regular structure into non- symmetrical one.” Such chiral nanostructures have a much
larger surface area than a straight nanowire of similar size. This makes them potentially useful for sensing applications. “We next hope to use the nanoscrews in the fabrication
of sensors and transparent conductors,” says Wei.
1. Tan, R. L. S., Chong, W. H., Feng, Y., Song, X., Tham, C. L., Wei, J., Lin, M. & Chen, H. Nanoscrews: Asymmetrical etching of silver nanowires. Journal of the American Chemical Society 138, 10770−10773 (2016).
Anxiety
AGORAPHOBIC FLIES HELP STUDIES ON HUMAN ANGST
WHAT ANXIOUS DROSOPHILA CAN TELL US ABOUT THE FUTURE OF ANTI-ANXIETY TREATMENTS
About 1 in 14 people in the world suffer
from an anxiety disorder. Research into the condition is a huge field, but despite the prevalence of the disorders and intense research, there are still no optimal drug treat- ments available. Now, a group at the A*STAR
Institute of Molecular and Cell Biology show that flies can be used to analyze basic anxiety mechanisms1. The image of a rat in a maze is a cliché
thanks to the widespread use of these animals in neuropsychiatric research. But using rats
and mice to analyze anxiety mechanisms and discover drugs to treat anxiety has not lately been successful. “The proof is in the pudding: rodent research hasn’t produced an effective new anxiolytic in at least 30 years,” says Adam Claridge-Chang, head of A*STAR’s Laboratory of Translational Neurogenetics. Vinegar flies, Drosophila melanogaster,
are a model system that has dominated the animal genetics field for more than a century. “I wondered if Drosophila could be also used to analyze anxiety,” says Farhan Mohammad, the project’s lead experimental scientist. Using automated video tracking to analyze the flies’ behavior, the group found that the animals naturally stuck close to the walls of a container, exhibiting ‘exposure avoidance’ behavior. When given diazepam, an anxiety-reducing
tranquilizer, the flies were more likely to venture from the walls. Deleting a serotonin transporter increased the wall-hugging behavior, suggesting increased anxiety. Sub- jecting the flies to environmental stress such as heat, physical restraint and social isolation provoked similar effects. These findings match those from mouse models, verifying that flies have an anxiety-like state that is regulated by similar pathways to humans. The scientists hope their research will complement and guide work in rodents.
"THERE ARE NO HUMAN GENES KNOWN TO BE ASSOCIATED WITH ANXIETY DISORDERS."
Using vinegar flies will improve exper- Flies walk on all surfaces but tend to stay near the edges of a chamber, a behavior that is thought to represent anxiety. 6 A*STAR RESEARCH
imental reliability by allowing researchers to conduct tests more quickly and cheaply and with much larger sample sizes. Also, the genetic tools available to modify Drosophila are far more advanced than for their mouse counterparts. The team was also able to show
ISSUE 6 | JANUARY – MARCH 2017
Reproduced from Ref. 1 and licensed under CC BY 4.0 (
https://creativecommons.org/licenses/by/4.0/) © 2016 Farhan Mohammed et al.
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