A switch in the brain

Research from Greg Jefferis’s group in the LMB’s Neurobiology Division has uncovered a biological switch that determines which part of the fruit fly’s brain responds to pheromones, depending on whether the fruit fly is male or female. Previous studies have identified differences in brain structure between the sexes but this study, published in Cell, is the first description in any animal of a specific change in nerve cell wiring that reroutes information between male and female brains.

Sex pheromones are chemicals that allow male and female animals to communicate by smell. In some cases it is known that exactly the same pheromone molecule can produce distinct behavioural responses in both males and females. Since both sexes respond to the molecule, there appears to be a difference in brain perception rather than sensory detection. For example in fruit flies, a male sex pheromone called cVA can stimulate females to mate with a male, while repelling other males at the same time. Greg’s group have been investigating exactly how the processing of this pheromone differs between male and female brains.

Jonny Kohl, Aaron Ostrovsky and Shahar Frechter from Greg’s lab first identified and labelled two groups of nerve cells inside the fly brain that respond to pheromones using a green fluorescent protein. One group of nerve cells responded to pheromone only in male brains, while the second group responded only in females. This difference in response depended on a changeover switch that rerouted incoming pheromone information to different groups of olfactory neurons in male and female flies.

Further experiments showed that this switch is set by the action of a control gene, called fruitless. Genetic manipulations allowed them to make a small number of nerve cells male in an otherwise female brain; this helped to pin point the exact location in the brain and the gene controlling the switch. The fruitless gene had previously been shown to control fruit flies’ sexual behaviour but exactly how it could achieve this through changes in brain wiring was unknown.

 One of the biggest challenges in biology today is to understand how the pattern of connections between individual nerve cells allows the brain to process and store information and respond to the outside world. Looking at the differences between the male and female brains of a species is one powerful approach to study the relationships between brain wiring and behaviour. Until now it has proven very difficult to identify specific and reproducible differences in brain wiring and understand how they could alter the flow of information between male and female brains. This research has now shown how this occurs in flies. Sex differences in brain structure and behaviour have been documented in organisms from worms to humans. This study suggests a general mechanism by which males and females could perceive or interpret the same stimulus, such as smell, differently. The same form of genetic regulation of wiring might also be at the origin of behavioural differences across species.

This work was supported by the Medical Research Council, European Research Council, and an EMBO Post-doctoral Fellowship.

Images: Gregory Jefferis. jefferis@mrc-lmb.cam.ac.uk Personal group site

Further References:

Paper in Cell
Greg’s group page



ORIGINAL: MRC
20th December, 2013
Copyright © 2013 MRC Laboratory of Molecular Biology.

Can Bees Be Trained to Sniff Out Cancer?

Credit: Susana Soares

Some insects, such as bees, have a sense of smell so acutely sensitive that they can locate the faintest of odors in a room, even if it consists of only a few molecules. But scientists are particularly intrigued by the fact that these bugs can even be taught to detect various chemicals, from methamphetamines to ingredients in explosives. They’ve even been shown to effectively diagnose diseases like tuberculosis and diabetes.

U.K.-based product designer Susana Soares has created a simple, elegant way of harnessing bees to screen for a number of diseases, including cancers, like tumors of the lung and ovaries. Her glass apparatus, called “Bee’s,” features a large chamber and a smaller connected chamber housed within it. After training the bees to associate a specific chemical odor with a food reward, such as sugar, the insects are released into the diagnostic device through an opening. Patients would simply blow into the smaller compartment and wait to see if a swarm gathers toward something alarming in the person’s breath.

The project, part of her master’s thesis at London’s Royal College of Art, began in 2007 when Soares came across research on bees and their phenomenal olfactory abilities. After talking to researchers in the field, she learned that certain diseases, such as lung cancer, noticeably alter the composition of bodily fluids, producing odorous compounds that show up in urine and sometimes blood. Some investigators have even been experimenting with various sensory methods to home in on these “biomarkers.” In Philadelphia, for instance, scientists have trained mice to identify the scent of lung cancer. Trained dogs have also been used to sniff out ovarian cancer. Others have focused on replicating these animal abilities in electronic nose devices that are calibrated to pick up these biomarkers undetectable to human noses.

Insects offer key advantages over mammals and electronics, however, because of their antennae. For example, electronic nose devices have trouble detecting an odor amid more complicated conditions, like when there’s a greater mixture of gases, as is found in human breath. And studies have revealed that sniffer dogs identify odors correctly only about 71 percent of the time, while also requiring at least three months’ training. Bees, in contrast, have achieved an accuracy rate of 98 percent and can be trained in about 10 minutes.

In developing “Bee’s,” the Portuguese native needed something that enabled the user to easily transport bees into the instrument and safely suck them back out using a vacuum. The source material also had to be malleable enough to shape into a system with well-defined pathways that don’t impede their movement. She eventually settled on glass as the material because of its flexibility and transparency. “To know the results of a breath test, you’d have to see the behavior of the insects,” she says. “Everything is about their behavior.”

Prototypes have undergone field testing, and although it didn’t find any instances of cancer, it did turn up a case of diabetes that was later confirmed. It’s unlikely, though, that the concept will amount to anything beyond being an exhibition curiosity. While there was a brief period in which she felt ambitious enough to reach out to potential collaborators, the process proved so time consuming and unfruitful that she ultimately gave up. The only organizations that seemed even remotely interested in her idea were a handful of charities. So for now, “Bee’s” exists as one of those purely academic exercises to show, as she puts it, the “symbiotic relationship” humans have with nature and how “technology and science can better foster these relationships.”

“I think there’s only four labs in the world doing research into insects for disease screening, which shows you that this approach doesn’t go over well in the western world,” says Soares. “Medical and health technologies are a big business, and the bottom line is they just don’t see how something like this can be profitable.”

Glen C. Rains, an agricultural professor at the University of Georgia, largely concurs, though he adds that there are more complex issues besides economics. The entomologist, as well as licensed beekeeper, has dealt with numerous challenges while developing a similar device called the Wasp Hound, which uses a batch of five wasps to detect the presence of bedbugs. Rains’ system is a bit more elaborate in that it uses a camera to record the wasps’ behavior. The data is then fed into software that analyzes these movements to determine if the bugs actually did indeed detect these unwanted guests. After over a decade of development, Rains has forged a partnership with Bennett Aerospace, an engineering firm, to refine the technology for large-scale real applications.

“The whole notion is definitely something people find fascinating,” he says. “But once you get into how it would work or how they make money, there’s no model for how it would be done.”

While there’s a tried-and-true market for electronic technologies, Rains points out that disease screening systems based on insects requires a separate infrastructure that the industry players haven’t bothered to think through. Facilities, for instance, would need a way to efficiently obtain odor samples for training and, obviously, a beekeeper on site who can manage and train the insects. After a few positive results, the insects’ willingness to buzz towards the chemical starts to diminish significantly, as they start to catch on to the fact that a sugary reward no longer await them at the other end. Thus, in a lab setting, bugs would need constant retraining throughout the day. But what’s encouraging, he adds, is that the enlisting of bugs for clinical purposes isn’t unprecedented, with the use of maggots and leaches to clean wounds being a well-accepted medical practice.

Despite these challenges, Soares has left at least the back door open to such a possibility, if someone with the right resources is willing to take a risk. “It has the potential to save so many lives,” she says. “It can even be an open-source concept, so for anyone who is interested, I’d be happy to talk.”

ORIGINAL: Smithsonian
December 13, 2013

01-intro

02-a-diagnostic-tool

03-a-precise-object

02-robert-hooke

Bee´s / Project
Bee's explores how we might co-habit with natural biological systems and use their potential to increase our perceptive abilities.

The objects facilitate bees' odour detection abilities in human breath. Bees can be trained within 10 minutes using Pavlov’s reflex to target a wide range of natural and man-made chemicals and odours, including the biomarkers associated with certain diseases.

The aim of the project is to develop upon current technological research by using design to translate the outcome into systems and objects that people can understand and use, engendering significant adjustments in their lives and mind set.

How it works

The glass objects have two enclosures: a smaller chamber that serves as the diagnosis space and a bigger chamber where previously trained bees are kept for the short period of time necessary for them to detect general health. People exhale into the smaller chamber and the bees rush into it if they detect on the breath the odour that they where trained to target.



01 & 02 Person preparing to exhale into the small chamber
03 Negative diagnostic: bees did not detect traces of odour they were trained to target
04 Positive diagnostic: bees rushed to the small chamber were they detect the targeted odour

What can bees detect?

Scientific research demonstrated that bees can diagnose accurately at an early stage a vast variety of diseases, such as: tuberculosis, lung and skin cancer, and diabetes.

Diagnostic tool 2: person exhaling into the diagnostic chamber, 26*15 cm, prototype 2007; borosilicate; Vilabo, Portugal

Precise object
The outer curved tube helps bees avoid from flying accidentally into the interior diagnosis chamber, making for a more precise result. The tubes connected to the small chamber create condensation, so that exhalation is visible.

Precise object, 22*12 cm, prototype 2007; borosilicate; Vilabo, Portugal

Detecting chemicals in the axilla
Apocrine glands are known to contain pheromones that retain information about a person's health that bees antennae can identify.

Diagnostic tool 4 (25*16 cm) prototype 2008; borosilicate; Vilabo, Portugal

The bee clinic

These diagnostic tools would be part of system that uses bees as a biosensor.

The systems implies:

• A BEE CENTRE: a structure that facilitates the technologic potential of bees. Within the centre is a BEEFARM, a TRAINING CENTRE, a RESEARCH lab and a HEALTHCARE CENTRE.
• TRAINING CENTER: courses can be taken on beetraining where bees are collected and trained by beetrainers. These are specialists that learn beetraining techniques to be used in a large scope of applications, including diagnosing diseases.
• BEE clinic: bees are used at the clinic for screening tests. These insects are very accurate in early medical diagnosis through detection on a person's breath. Bees are a sustainable and valuable resource. After performing the diagnose in the clinic they are released, returning to their beehive. 

Bee Graphic - Complete Cycle

What if people started to be screened by bees for cancer?
Which one would we trust more, a machine or a biosensor?
Could bee training become a profession?

Bee training
Bees can be easily trained using Pavlov’s reflex to target a wide range of natural and man-made chemicals odours including the biomarkers associated with certain diseases. The training consists in baffling the bees with a specific odour and feeding them with a solution of water and sugar, therefore they associate that odour with a food reward.

05 Bee catcher: this object is use to collect bees for training, a sugary solution is used to attract them inside - 15*9 cm, prototype 2009; acrylic.

06 Bee training object - 20*7*9 cm, prototype 2009; clear acrylic & hip.

Acknowledgements:

• Calouste Gulbenkian Foundation
• Royal College of Art, Design Interactions Department: Professor Anthony Dunne and Ms. Fiona Raby
• Crisform: Designer Sónia Durães and Glass Master Mateus
• Vilabo: Mr. João Gomes
• London Beekeeper Association: Mr. David Perkins
• Inscentinel, Bee research team at Rothamsted Research, UK: Dr. Mathilde Briens

Credits:
Susana Soares

Models:
Bernardete Fernandes
Clarie Ducruet
Margarida Martins

New Mosquito Repellent Made, "Better Than Anything Else"

ORIGINAL: NatGeo
Christine Dell'Amore for National Geographic
September 17, 2013

Formula uses human compounds to block mosquitoes' sense of smell.

Mosquitoes avoid a hand treated with DEET (right).  Photograph by Greg Allen, USDA-ARS

Mosquitoes bugging you? There may be a new repellent on the horizon—and it's "so much better than anything else we've ever seen," its inventor says.

A few years ago, Ulrich Bernier was busy blending various chemicals together in the lab, hoping to figure out why the blood-sucking insects bite some people more than others. Mosquitoes home in on their targets by sniffing out various chemicals and bacteria on human skin.

When he created one blend with a group of chemicals that are very similar to ones found in low concentrations in our bodies, Bernier noticed that the bugs seemed to ignore it. (Read what happens inside you when a mosquito bites.)

These chemicals—which include the tongue twisters homopiperazine and 1-methylhomopiperazine, among others—seemed to have an incredibly robust ability to mask our scent from mosquitoes, said Bernier, a research chemist at the United States Department of Agriculture's Agricultural Research Service.

Next, Bernier and colleagues set up an experiment where people put their arms or hands inside a cage full of mosquitoes. The insects avoided the skin of the subjects when the chemical cocktail was released from a container inside the cage.

Bernier and colleagues created a formula of several chemicals for a repellent, which was approved by the U.S. Patent and Trademark Office in 2012.

"It's a pretty neat discovery because I don't think anyone else has shown chemicals this capable of blocking skin odors that are normally attractive to mosquitoes," said Bernier, who presented the research at the American Chemical Society meeting in Indianapolis last week.

Why do we need a new repellent?
Insect-borne diseases are prevalent and potentially dangerous. According to the U.S. Centers for Disease Control and Prevention, there are about 30,000 annual reported cases of Lyme disease, which is transmitted by ticks, and at least a thousand annual cases of mosquito-caused encephalitis—which includes West Nile virus—in the country. Bernier and colleagues' new repellent is also effective against other blood-sucking insects.

The most common insect repellent now in use is DEET, which is designed to be sprayed on the skin. However, there has been some concern about DEET and potential toxicity, and there's high demand for equally effective alternatives. (See "Mutant Mosquitoes Not Repelled by DEET.")

How does it work?
Bug repellents like DEET work by deterring mosquitoes that find the smell unappealing; the new formula actually makes you invisible to the insect.

Here's an analogy to explain the two: If you walk into a room and smell something bad and leave, that's how DEET works. But with the new repellent, it's as if you walk into a room and don't smell anything, Bernier said.

Bernier said it's unknown why insects can't smell the compounds.

How is the repellent applied?
Commercial availability is still far down the road—there needs to be more toxicology tests on the formula, as well as field tests, Bernier cautioned.

But he said that it could be used indoors or outdoors and would probably work best released into the air rather than applied to the skin. For example, the repellent could be emitted from a sealed canister that releases a vapor slowly into the air, creating a sort of protective bubble around your environment.

For instance, if you're sitting outside on a patio, you could install several canisters around the patio, he suggested.

Landmine detecting bees create a buzz . Croatian honeybees being trained to sniff out land mines and save lives.

ORIGINAL: Tiramisu (Toolbox Implementation for Removal of Anti-Personal Mines, Submunitions and Uxo)

Sugar-craving honeybees could help Europe avoid deadly landmine explosions. Researchers in Croatia have been developing a unique method of finding leftover mines from Croatia's war in the 1990s. According to bee behavior expert, Professor Nikola Kezic, the bees have a perfect sense of smell that can even detect the odor of explosives, and they are being trained to identify TNT.

TIRAMISU

Project Overview




Anti-personnel landmines and unexploded ordnance (UXOs) represent an important obstacle in the transition from crisis to peace for war affected countries. They threaten post-conflict development and welfare.

The objective of the TIRAMISU project is to provide the Mine Action community with a toolbox to assist in addressing the many issues related to Humanitarian Demining and thus promoting peace, national and regional security, conflict prevention, social and economic rehabilitation and post-conflict reconstruction.

The tools in development are divided in three main categories:

1. Demining planning tools, which will help locating the threats and define the contaminated areas.
2. Detection and disposal tools, which will physically neutralise mines and UXOs and improve operators’ safety.
3. Training and Mine Risk education tools.

These tools will be tested and validated in mine-affected countries and will also benefit from state-of-the-art technologies (robots, UAV...).