Tuesday, January 7, 2025

Bittersweet secrets of the fruit fly brain

Fruit flies have served as an important laboratory organism for more than 100 years. (Sanjay Archaya/Wikipedia)

The sense of taste carries evolutionary benefits key to survival. A sweet taste, for instance, signals energy-dense nutrients important to animals foraging for food — including humans. A bitter taste may warn of a toxic substance. 

“We use our sense of taste to decide what to eat and how much to eat,” says Anita Devineni, a neuroscientist and assistant professor in Emory University’s Department of Biology. 

Despite the importance of taste, little is known about how taste cues spark the firing of cells across a brain and evoke a variety of behavioral responses. Devineni is exploring this mystery by mapping the neural circuitry for the taste system of the fruit fly, Drosophila melanogaster

Tinier than a poppy seed, the fruit fly brain contains around 140,000 neurons. 

“That’s 1,000 fewer neurons than a mouse brain and a million times fewer than a human brain,” Devineni explains, making the fly brain a simple starting point for studying general mechanistic principles of cognition. 

Compared to the incredible complexity of its cognitive powers, the human brain’s basic biology appears relatively straightforward. 

“The brain is just an organ like any other organ in your body,” Devineni says. “It’s made up of neurons that are cells like any other cells — lipid membranes containing proteins, DNA and other molecules. What makes a brain cell different from a skin cell or a lung cell is that a brain cell fires. Firing means that sodium ions flow in and out of the cell. Everything that you do, from thinking to talking to walking, is a result of patterns of neurons firing. How could this be?”


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Friday, December 13, 2024

High temperatures dampen immune systems of wild capuchins

A capuchin mother carries a baby on her back. The study found that the immune systems of juveniles were most impacted by high temperatures. (Capuchins de Taboga)

High temperatures lower the immune performance of wild capuchin monkeys in Costa Rica, especially in young individuals, finds a new study published by Science Advances. The work, led by scientists at Emory University and the University of Michigan, provides some of the first data on the relationship between the immune system and ambient temperature in a wild mammal. 

“Capuchin monkeys are super intelligent, highly adaptive primates that do well in diverse ecosystems,” says Marcela Benítez, Emory assistant professor of anthropology and co-senior author of the paper. “The fact that we’re seeing their immune responses affected by high temperatures suggests that many mammalian species that are less adaptive may be experiencing even worse effects as average temperatures warm globally.” 


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Thursday, November 21, 2024

A snapshot of scientific thought on emotions in animals

Wild capuchin monkeys in Costa Rica where Emory anthropologist Marcela Benítez is studying their social behaviors. (Capuchinos de Taboga)

The journal Royal Society Open Science published a survey of 100 researchers of animal behavior, providing a unique view of current scientific thought on animal emotions and consciousness. 

“As far as we know, this is the first assessment of how animal behavior researchers across a range of disciplines think about emotions and consciousness in non-human animals,” says Marcela Benítez, assistant professor of anthropology at Emory University and corresponding author of the paper. “It gives us a snapshot in time so that 20 years from now, we can revisit how scientific experts may have changed their views.” 

A majority of the survey respondents ascribed emotions to “most” or “all or nearly all” non-human primates (98%), other mammals (89%), birds (78%), octopus, squids and cuttlefish (72%) and fish (53%). And most of the respondents ascribed emotions to at least some members of each taxonomic group of animals considered, including insects (67%) and other invertebrates (71%). 

The survey also included questions about the risks in animal behavioral research of anthropomorphism (inaccurately projecting human experience onto animals) and anthropodenial (willful blindness to any human characteristics of animals). 

“It’s surprising that 89% of the respondents thought that anthropodenial was problematic in animal behavioral research, compared to only 49% who thought anthropomorphism poses a risk,” Benítez says. “That seems like a big shift.” 

Anthropomorphism, she notes, has long been a leading argument against those who attributed feelings to animals.


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Wednesday, November 13, 2024

Chemists showcase power of pathbreaking method to make complex molecules

"We've had tremendous impact on developing C-H functionalization as both an academic discipline and for industry applications," says Emory chemist Huw Davies, who brought researchers from 15 universities together under the umbrella of the NSF Center for C-H Funcitonalization.

Chemists synthesized a highly complex natural molecule through a revolutionary strategy of functionalizing normally inert carbon-hydrogen (C-H). Science published the breakthrough led by chemists at Emory University and Caltech. 

The work is the most dramatic example yet of a sequence of C-H functionalization reactions selectively transforming low-cost materials into complex building blocks of organic chemistry. Ten of the steps involved in their synthesis of cylindrocyclophane A — a natural compound with antimicrobial properties — involved C-H reactions. 

“It’s by far the most complex natural product we have made using our method,” says Huw Davies, Emory professor of chemistry and co-corresponding author of the paper. “This is a game changer. We’re doing chemistry on C-H bonds that formerly would have been considered as unreactive. And we’ve shown how we can orchestrate a suite of 10 C-H functionalization steps, targeting a single C-H bond at a time in a specific sequence.” 

“This work moves the field forward by showing the power of C-H functionalization,” adds Brian Stoltz, professor of chemistry at Caltech and co-corresponding author of the paper. “It will open people’s eyes to the possibilities of using these very selective and unusual transformations in a really complex setting.” 

First author is Aaron Bosse, who did the work as an Emory PhD student. Bosse has since graduated and is now a medicinal chemist at Takeda Pharmaceuticals in Cambridge, Massachusetts.





Tuesday, October 29, 2024

Bacterial pathogen shows alarming resistance to common cleaners, chemists discover


A new study reveals widespread resistance of a major bacterial pathogen to the active ingredients in cleaning agents commonly used in hospitals and homes. 

The American Chemical Society Infectious Diseases published the research led by chemists at Emory University. It demonstrates the surprising level of resistance to cleaning agents of multidrug-resistant Pseudomonas aeruginosa, a pathogen of particular concern in hospital settings. 

The study also identifies biocides that are highly effective against P. aeruginosa, including a novel compound developed at Emory in collaboration with Villanova University. The researchers describe how these biocides work differently than most disinfectants currently in use. 

“We hope our findings can help guide hospitals to reconsider protocols for the sanitation of patient rooms and other facilities,” says William Wuest, Emory professor of chemistry and a senior author of the study. “We also hope that our findings of a new mechanism of action against these bacterial strains may help in the design of future disinfectant products.” 

First authors of the study are Christian Sanchez (who did the work as an Emory PhD student in chemistry and, following graduation, joined the faculty at Samford University) and German Vargas-Cuebas, an Emory PhD candidate in microbiology through Laney Graduate School. 

“Resistance of pathogens to cleaning agents is an area that’s often overlooked,” Vargas-Cuebas says, “but it’s an important area of study, especially with the rise in antibiotic-resistant pathogens worldwide.”


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