The art of smell: Research suggests the brain processes smell both like a painting and a symphony

What happens when we smell a rose? How does our brain process the essence of its fragrance? Is it like a painting – a snapshot of the flickering activity of cells – captured in a moment in time? Or like a symphony, an evolving ensemble of different cells working together to capture the scent? New research suggests that our brain does both.

“These findings reveal a core principle of the nervous system, flexibility in the kinds of calculations the brain makes to represent aspects of the sensory world,” said Krishnan Padmanabhan, Ph.D., an associate professor of Neuroscience and senior author of the study recently published in Cell Reports. “Our work provides scientists with new tools to quantify and interpret the patterns of activity of the brain.”

Researchers developed a model to simulate the workings of the early olfactory system – the network the brain relies on for smelling. Employing computer simulations, they found a specific set of connections, called centrifugal fibers, which carry impulses from other parts of the central nervous system to the early sensory regions of the brain, played a critical role. These centrifugal fibers act as a switch, toggling between different strategies to efficiently represent smells. When the centrifugal fibers were in one state, the cells in the piriform cortex – where the perception of an odor forms – relied on the pattern of activity within a given instant in time. When the centrifugal fibers were in the other state, the cells in the piriform cortex improved both the accuracy and the speed with which cells detected and classified the smell by relying on the patterns of brain activity across time.

These processes suggest the brain has multiple responses to representing a smell. In one strategy, the brain uses a snapshot, like a painting or a photograph, at a given moment to capture the essential features of the odor. In the other strategy, the brain keeps track of the evolving patterns. It is attuned to which cells turn on and off and when – like a symphony.

The dark matter of the brain

Electrical synapses connect neurons in almost all brains; however, little is known about them. A study now shows for the first time where these specific synapses occur in the fruit fly brain and that they influence the function and stability of nerve cells.
Credit: MPI for Biological Intelligence, i.f. / Julia Kuhl

They are part of the brain of almost every animal species, yet they remain usually invisible even under the electron microscope. "Electrical synapses are like the dark matter of the brain," says Alexander Borst, director at the MPI for Biological Intelligence, in foundation (i.f). Now a team from his department has taken a closer look at this rarely explored brain component: In the brain of the fruit fly Drosophila, they were able to show that electrical synapses occur in almost all brain areas and can influence the function and stability of individual nerve cells.

Neurons communicate via synapses, small contact points at which chemical messengers transmit a stimulus from one cell to the next. We may remember this from biology class. However, that is not the whole story. In addition to the commonly known chemical synapses, there is a second, little-known type of synapse: electrical synapse. "Electrical synapses are much rarer and are hard to detect with current methods. That's why they have hardly been researched so far," explains Georg Ammer, who has long been fascinated by these hidden cell connections. "In most animal brains, we therefore don't know even basic things, such as where exactly electrical synapses occur or how they influence brain activity."

Boeing’s Spectrolab to Power NASA’s Roman Space Telescope

Spectrolab, Inc., a wholly owned subsidiary of Boeing, will build the solar cells and integrate solar panels for NASA’s Roman Space Telescope.
Credit: GSFC/SVS

Spectrolab, Inc., a wholly owned subsidiary of Boeing [NYSE: BA], will manufacture, integrate and test approximately 4,000 XTJ Prime solar cells for NASA’s Nancy Grace Roman Space Telescope.

“Using Spectrolab’s XTJ Prime solar cells, NASA will be able to maximize the Roman Space Telescope’s power generation, allowing greater data gathering capability while operating in a unique mission environment at the L2 Lagrange point,” said Tony Mueller, president of Spectrolab. “These cells leverage both heritage and high efficiency for the agency’s newest universe studying telescope.”

Spectrolab’s NeXt Triple Junction (XTJ) Prime solar cells will provide power to the telescope, including its two main instruments – the Wide Field Instrument and the Coronagraph Instrument – as well as the primary mirror that is 2.4 meters in diameter (7.9 feet), and is the same size as the Hubble Space Telescope's primary mirror. The solar array consists of six panels, each approximately 3m-by-2.5m and consists of 4,000 triple junction solar cells. Triple junction solar cells leverage multiple bandgaps tuned to different wavelengths of the solar spectrum, allowing higher efficiencies not possible with commercially available silicon solar cell technology.

Historic Hypersonic Flight

Artist rendering of the Hypersonic Air-breathing Weapon Concept (HAWC), the result of a partnership between the Defense Advanced Research Projects Agency, Air Force Research Lab, Lockheed Martin and Aerojet Rocketdyne.
Credit: Lockheed Martin Corporation

The Defense Advanced Research Projects Agency (DARPA), Air Force Research Lab (AFRL), Lockheed Martin (NYSE: LMT) and Aerojet Rocketdyne (NYSE: AJRD) team successfully flight tested the Hypersonic Air-breathing Weapon Concept (HAWC). This historic flight reached speeds in excess of Mach 5, altitudes greater than 65,000 feet and furthers the understanding of operations in the high-speed flight regime.

"Our work with DARPA and AFRL on the HAWC program demonstrates that air-breathing hypersonic systems are a cost-effective solution to address rapidly emerging threats in the global security arena," said John Clark, vice president and general manager Lockheed Martin Skunk Works®. "The success of this flight test is evidence that a strong partnership between government and industry is key to solving our nation's most difficult challenges and enabling new capabilities to counter threats to U.S. and allied forces."

Evidence Shows Violent Collapse Responsible for Formation of Jupiter-Like Protoplanet

This is an artist's illustration of a massive, newly forming exoplanet called AB Aurigae b. Researchers used new and archival data from the Hubble Space Telescope and the Subaru Telescope to confirm this protoplanet is forming through an intense and violent process, called disk instability.
Credits: NASA, ESA, Joseph Olmsted (STScI)

NASA's Hubble Space Telescope has directly photographed evidence of a Jupiter-like protoplanet forming through what researchers describe as an "intense and violent process." This discovery supports a long-debated theory for how planets like Jupiter form, called "disk instability."

The new world under construction is embedded in a protoplanetary disk of dust and gas with distinct spiral structure swirling around, surrounding a young star that's estimated to be around 2 million years old. That's about the age of our solar system when planet formation was underway. (The solar system's age is currently 4.6 billion years.)

"Nature is clever; it can produce planets in a range of different ways," said Thayne Currie of the Subaru Telescope and Eureka Scientific, lead researcher on the study.

In the heat of the wound

Empa researcher Fei Pan is working on a membrane made of nanofibers that releases medication only when the material heats up. Such a membrane could, for example, become active in a bandage as soon as inflammation starts.
Image: Empa

A bandage that releases medication as soon as an infection starts in a wound could treat injuries more efficiently. Empa researchers are currently working on polymer fibers that soften as soon as the environment heats up due to an infection, thereby releasing antimicrobial drugs.

It is not possible to tell from the outside whether a wound will heal without problems under the dressing or whether bacteria will penetrate the injured tissue and ignite an inflammation. To be on the safe side, disinfectant ointments or antibiotics are applied to the wound before the dressing is applied. However, these preventive measures are not necessary in every case. Thus, medications are wasted and wounds are over-treated.

Even worse, the wasteful use of antibiotics promotes the emergence of multi-resistant germs, which are an immense problem in global healthcare. Empa researchers at the two Empa laboratories Biointerfaces and Biomimetic Membranes and Textiles in St. Gallen wants to change this. They are developing a dressing that autonomously administers antibacterial drugs only when they are really needed.

The idea of the interdisciplinary team led by Qun Ren and Fei Pan: The dressing should be "loaded" with drugs and react to environmental stimuli. "In this way, wounds could be treated as needed at exactly the right moment," explains Fei Pan. As an environmental stimulus, the team chose a well-known effect: the rise in temperature in an infected, inflamed wound.

Invading Hordes of Crazy Ants May Have Finally Met Their Kryptonite

 

Tawny crazy ants swarm on a cobweb spider.
Credit: Mark Sanders.

When tawny crazy ants move into a new area, the invasive species is like an ecological wrecking ball — driving out native insects and small animals and causing major headaches for homeowners. But scientists at The University of Texas at Austin have good news, as they have demonstrated how to use a naturally occurring fungus to crush local populations of crazy ants. They describe their work this week in the journal Proceedings of the National Academy of Sciences.

“I think it has a lot of potential for the protection of sensitive habitats with endangered species or areas of high conservation value,” said Edward LeBrun, a research scientist with the Texas Invasive Species Research Program at Brackenridge Field Laboratory and lead author of the study.

In some parts of Texas, homes have been overrun by ants that swarm breaker boxes, AC units, sewage pumps and other electrical devices, causing shorts and other damage. Natives of South America, tawny crazy ants have raised alarm bells as they’ve spread across the southeastern U.S. during the past 20 years. The idea for using the fungal pathogen came from observing wild populations of crazy ants becoming infected and collapsing without human intervention.

“This doesn’t mean crazy ants will disappear,” LeBrun said. “It’s impossible to predict how long it will take for the lightning bolt to strike and the pathogen to infect any one crazy ant population. But it’s a big relief because it means these populations appear to have a lifespan.”

Other study authors are Rob Plowes and Lawrence Gilbert at Brackenridge Field Laboratory, and Melissa Jones formerly of the Texas Parks and Wildlife Department.

New method purifies hydrogen from heavy carbon monoxide mixtures

Chris Arges (right), Penn State associate professor of chemical engineering, proposes using high-temperature proton-selective polymer electrolyte membranes, or PEMs, to separate hydrogen from other gases in an ACS Energy Letters paper. Co-author Deepra Bhattacharya, Penn State doctoral student in chemical engineering, is seen at left.
Credit: Kelby Hochreither/Penn State.

Refining metals, manufacturing fertilizers and powering fuel cells for heavy vehicles are all processes that require purified hydrogen. But purifying, or separating, that hydrogen from a mix of other gases can be difficult, with several steps. A research team led by Chris Arges, Penn State associate professor of chemical engineering, demonstrated that the process can be simplified using a pump outfitted with newly developed membrane materials.

The researchers used an electrochemical hydrogen pump to both separate and compress hydrogen with an 85% recovery rate from fuel gas mixtures known as syngas and 98.8% recovery rate from conventional water gas shift reactor exit stream — the highest value recorded. The team detailed their approach in ACS Energy Letters.

Traditional methods for hydrogen separations employ a water gas shift reactor, which involves an extra step, according to Arges. The water gas shift reactor first converts carbon monoxide into carbon dioxide, which is then sent through an absorption process to separate the hydrogen from it. Then, the purified hydrogen is pressurized using a compressor for immediate use or for storage.

Fuel from waste wood

In collaboration with the Lappeenranta-Lahti University of Technology (LUT) in Finland, researchers at the Straubing Campus for Biotechnology and Sustainability of the Technical University of Munich (TUM) have developed a new process for the production of ethanol.
Image: Maria Schießl / TUM

According to the latest assessment report from the Intergovernmental Panel on Climate Change, a considerable reduction in CO2 emissions is required to limit the consequences of climate change. Producing fuel from renewable sources such as waste wood and straw or renewable electricity would be one way to reduce carbon emissions from the area of transportation. This is an area which is being addressed by researchers at the Technical University of Munich (TUM).

Ethanol is usually produced through the fermentation of sugars from starchy raw materials such as corn, or from lignocellulosic biomass, such as wood or straw. It is an established fuel that decarbonizes the transportation sector and can be a building block to reduce emissions of CO2 over the long term. In collaboration with the Lappeenranta-Lahti University of Technology (LUT) in Finland, researchers at the Straubing Campus for Biotechnology and Sustainability of the Technical University of Munich (TUM) have developed a new process for the production of ethanol.

Accelerated biological aging may cause bowel cancer

Scientists have shown how accelerated biological aging measured by an epigenetic clock may increase the risk of bowel cancer, according to a report published today in eLife.

The study provides evidence that biological age might play a causal role in the increased risk of certain diseases, and paves the way for interventions that could slow down this process.

Epigenetic markers are changes to DNA which may alter the way in which our genes work and are known to vary as we age. A type of epigenetic marker called DNA methylation is often used to measure age. DNA methylation patterns on the genome have been shown to relate closely with age and they can provide insights into 'biological aging' – that is, how old our cells look compared to how old they are in years.

“When an individual’s biological age is older than their chronological age, they are said to be experiencing epigenetic age acceleration,” explains first author Fernanda Morales-Berstein, a Wellcome Trust PhD Student in Molecular, Genetic and Lifecourse Epidemiology at the MRC Integrative Epidemiology Unit, University of Bristol. “Epigenetic age acceleration, as measured by DNA methylation-based predictors of age called epigenetic clocks have been associated with several adverse health outcomes including cancer. But although epigenetics can be used to predict cancer risk or detect the disease early, it is still unclear whether accelerated epigenetic aging is a cause of cancer.”