PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

'Bug brain soup' expands menu for scientists studying animal brains

By mashing up brains from various insect species, neuroscientists at the University of Arizona were able to count the neurons in individual brains, providing a more meaningful metric than traditional studies measuring brain size or weight.

'Bug brain soup' expands menu for scientists studying animal brains
2021-04-08
(Press-News.org) Using a surprisingly simple technique, researchers in the University of Arizona Department of Neuroscience have succeeded in approximating how many brain cells make up the brains of several species of bees, ants and wasps. The work revealed that certain species of bees have a higher density of brain cells than even some species of birds, whereas ants turned out to have fewer brain cells than originally expected.

Published in the scientific journal Proceedings of the Royal Society B, the study marks the first time the new cell counting method has been applied to invertebrate animals and provides a robust and reproducible protocol for other research groups studying the brains of invertebrate animals.

For more than a century, scientists have attempted to measure and compare the brains and brain components of vertebrates across species in efforts to draw conclusions about how brains support the animals' behavioral and cognitive abilities and ecological requirements. Theories of cognitive capacities of animal brains, including those of fossilized remains of the evolutionary ancestors of humans, are based on such measures.

To that end, scientists need to know how many neurons make up a given brain. Until recently, it was extremely tedious and time-consuming to count or estimate the number of neurons in a brain, even with computer and software-based systems.

For this reason, there were very few reliable neuron numbers available for any animals, including the human brain. Instead, brain researchers relied on estimates and extrapolations based on measurements of brain size or mass. But that approach can be fraught with uncertainties and biases, according to the authors of this study. For example, while larger animals, as a general rule, tend to have larger brains than smaller animals, the volume and mass of a given brain alone don't say much about its cognitive capabilities. "How big or how heavy a brain is does not give you the best measure of an animal's cognitive capabilities," says the study's lead author, R. Keating Godfrey, a postdoctoral researcher in the Department of Molecular and Cellular Biology.

Why 'bird brain' Is actually a compliment

One major reason is that the size of a brain is less relevant for its processing capacities compared with the number of neurons, or nerve cells, it contains. This is analogous to the processing power of a computer, which has little to do with the physical size of its central processor. Neurons are highly specialized types of cells found in virtually any species across the animal kingdom.

Contrast, for example, the sea hare - a giant sea slug found off the coast of California that can weigh more than 12 pounds - with the fruit fly Drosophila. The sea slug's brain alone dwarfs the entire fly by a lot, yet it has just 18,000 neurons, far fewer than the fly's approximately 100,000.

"Just because the brain of one species may be 10 times larger than that of another does not mean it has 10 times as many neurons," says the paper's senior author, Wulfila Gronenberg, a professor of neuroscience who heads a Department of Neuroscience research group dedicated to unraveling the mysteries of insect brains.

Whereas "bird brain" is widely used as a derogatory term for a lack of intelligence, it actually is a misnomer, Gronenberg says.

"Bird brains have many more neurons than a typical mammal of comparable size," he says. "Birds have to navigate a three-dimensional space by flight, and in order to get all that processing power into a small, lightweight package, their neurons are smaller and more densely packed."

Social brains

Gronenberg's research group is interested in the neuronal underpinnings of insects that live in social communities, like honeybees or many wasps.

"We wanted to know: Is there something special about the brains of social insects?" Godfrey says.

Specifically, she and her colleagues set out to study whether the "social brain" hypothesis, which was developed for vertebrate animals and postulates that the size of a brain or particular brain region is correlated with social group size and group behaviors, also holds true for social insects.

With the help of undergraduate students, Godfrey worked on adapting a technique - developed in 2005 by Brazilian neuroscientist Suzanna Herculano-Houzel that revolutionized the field of vertebrate neuroscience - to the insect brains. Instead of slicing brains into hundreds or thousands of thin sections and counting neurons in each section, the method requires only that the brain tissue is homogenized. That's science speak for "blended," which results in a brain soup.

"We release the nuclei from the cells so we can count them," Godfrey says. "Vertebrates have dedicated brain regions and structures that you can sample from, but in insects, we can only really squish the whole thing. So we get a neuron density count for the entire brain."

Godfrey and her co-authors compared the brain cell counts with the body sizes of a large range of hymenoptera - bees, wasps and ants - and found that the neuron number and brain size relationships are very similar to those found in vertebrates.

Putting a number on an ant brain

Certain bees, the team reports, have particularly high numbers of neurons, which should stimulate renewed research into their behavioral capacities, and ants, in general, have fewer neurons than their wasp and bee relatives, probably because they do not fly and thus need less brain power for visual processing and flight control.

Some bees, it turned out, have even higher brain cell densities than some of the most compact bird and mammal brains. For example, the metallic green sweat bee, which is commonly seen in the Southwest and belongs to the genus Augochlorella, has a particularly high number of neurons for its brain size: about 2 million per milligram, more than the highest neuron densities found in the smallest vertebrate species - smoky shrews in mammals and goldcrests in birds.

Ants, on the other hand, tended to come in on the lower end of the spectrum. Compared with bees and wasps, ants had small brains and relatively few brain cells. A desert harvesting ant species common in Arizona amounted to just 400,000 cells per milligram of brain mass. Considering that this ant's brain weighs in at less than 1 milligram, this animal makes do with a total of 90,000 or so brain cells, Gronenberg estimates.

"We think this has to do with the ability to fly, which would make it less about intelligence but more about processing of information," he says. "Ants rely on scent information, whereas bees rely more on visual information."

How low can you go?

These findings beg the question of how many brain cells nature needs to make a functioning brain. Invertebrate brains tend to have highly specialized neurons, each performing a certain task, according to the authors of the study, which allows them to accomplish tasks with a small brain and a small number of neurons.

Gronenberg points to the tiny fairy wasp as a strong contender for the "tiniest brain in the insect world" award. Three strands of human hair, laid side by side, would cover the body length of the tiny creature, whose brain consists of fewer than 10,000 neurons.

"Yet, this parasitic wasp can do all the things it needs to do to survive," Gronenberg says.

"It can find a host, it can mate, it can lay eggs, it can walk and it can fly," he says. "While a small insect may just have one or a few neurons to perform a particular function, humans and other vertebrates tend to have many thousands, or even tens of thousands, of these specialized neurons dedicated to one task, which allows us to do things more precisely and in a more sophisticated way."

INFORMATION:

The research paper was co-authored by Mira Swartzlander, who participated in the work in Gronenberg's lab as part of the KEYS Research Internship Program, a summer research opportunity for high school students offered by the UArizona BIO5 Institute.

This work was supported by the National Science Foundation (grant number ISO-1354191) and a fellowship from the university's Graduate Interdisciplinary Program.


[Attachments] See images for this press release:
'Bug brain soup' expands menu for scientists studying animal brains

ELSE PRESS RELEASES FROM THIS DATE:

Novel diarylamides as orally active diuretics targeting urea transporters

Novel diarylamides as orally active diuretics targeting urea transporters
2021-04-08
Discovery of novel diarylamides as orally active diuretics targeting urea transporters Urea transporters (UT) play a vital role in the mechanism of urine concentration and are recognized as novel targets for the development of salt-sparing diuretics. Thus, UT inhibitors are promising for development as novel diuretics. In this study the authors discovered a novel UT inhibitor with a diarylamide scaffold by high-throughput screening. Optimization of the inhibitor led to the identification of a promising preclinical candidate, N-[4-(acetylamino)phenyl]-5-nitrofuran-2-carboxamide ...

Complete chromosome 8 sequence reveals novel genes and disease risks

Complete chromosome 8 sequence reveals novel genes and disease risks
2021-04-08
The full assembly of human chromosome 8 is reported this week in Nature.  While on the outside this chromosome looks typical, being neither short nor long or distinctive, its DNA content and arrangement are of interest in primate and human evolution, in several immune and developmental disorders, and in chromosome sequencing structure and function generally. This linear assembly is a first for a human autosome - a chromosome not involved in sex determination. The entire sequence of chromosome 8 is 146,259,671 bases. The completed assembly fills in the gap of more than 3 million bases missing from the current reference genome.   The Nature paper is titled "The structure, function and evolution of a complete chromosome 8." One of several intriguing characteristics ...

Energy transmission by gold nanoparticles coupled to DNA structures

2021-04-08
Using DNA structures as scaffolds, Tim Liedl, a scientist of Ludwig-Maximilians-Universitaet (LMU) in Munich, has shown that precisely positioned gold nanoparticles can serve as efficient energy transmitters.  Since the inception of the field in 2006, laboratories around the world have been exploring the use of 'DNA origami' for the assembly of complex nanostructures. The method is based on DNA strands with defined sequences that interact via localized base pairing. "With the aid of short strands with appropriate sequences, we can connect specific regions of long DNA molecules together, rather like forming three-dimensional structures by folding a flat sheet of paper in certain ...

Living fossils: Microbe discovered in evolutionary stasis for millions of years

Living fossils: Microbe discovered in evolutionary stasis for millions of years
2021-04-08
It's like something out of science fiction. Research led by Bigelow Laboratory for Ocean Sciences has revealed that a group of microbes, which feed off chemical reactions triggered by radioactivity, have been at an evolutionary standstill for millions of years. The discovery could have significant implications for biotechnology applications and scientific understanding of microbial evolution. "This discovery shows that we must be careful when making assumptions about the speed of evolution and how we interpret the tree of life," said Eric Becraft, the lead author on the paper. "It is possible that some organisms go into an evolutionary ...

Acrylamide derivatives for the treatment of rheumatoid arthritis

Acrylamide derivatives for the treatment of rheumatoid arthritis
2021-04-08
Design, synthesis, molecular modeling, and biological evaluation of acrylamide derivatives as potent inhibitors of human dihydroorotate dehydrogenase for the treatment of rheumatoid arthritis Human dihydroorotate dehydrogenase (DHODH) is a viable target for the development of therapeutics to treat cancer and immunological diseases, such as rheumatoid arthritis (RA), psoriasis and multiple sclerosis (MS). The authors designed and synthesized a series of acrylamide-based novel DHODH inhibitors as potential RA treatment agents. 2-Acrylamidobenzoic acid analog 11 was identified as the lead compound for structure-activity ...

Where Siberian orchids thrive: New hotspot of orchids discovered near Novosibirsk

Where Siberian orchids thrive: New hotspot of orchids discovered near Novosibirsk
2021-04-08
Orchids of the Boreal zone are rare species. Most of the 28,000 species of the Orchid family actually live in the tropics. In the Boreal zone, ground orchids can hardly tolerate competition from other plants -- mainly forbs or grasses. So they are often pushed into ecotones -- border areas between meadows and forests, or between forests and swamps. Furthermore, there has been a decline in wild orchids all over North America and Eurasia, caused in part by human-induced destruction of their habitats, the transformation of ecosystems, and the harvesting of flowers from the wild. In the Novosibirsk region, ...

Research gives new insight into formation of the human embryo

2021-04-08
Pioneering research led by experts from the University of Exeter's Living Systems Institute has provided new insight into formation of the human embryo. The team of researchers discovered an unique regenerative property of cells in the early human embryo. The first tissue to form in the embryo of mammals is the trophectoderm, which goes on to connect with the uterus and make the placenta. Previous research in mice found that trophectoderm is only made once. In the new study, however, the research team found that human early embryos are able to regenerate trophectoderm. They also showed that human embryonic stem cells grown in the laboratory can similarly ...

More than 5,000 tons of extraterrestrial dust fall to Earth each year

More than 5,000 tons of extraterrestrial dust fall to Earth each year
2021-04-08
Every year, our planet encounters dust from comets and asteroids. These interplanetary dust particles pass through our atmosphere and give rise to shooting stars. Some of them reach the ground in the form of micrometeorites. An international program conducted for nearly 20 years by scientists from the CNRS, the Université Paris-Saclay and the National museum of natural history with the support of the French polar institute, has determined that 5,200 tons per year of these micrometeorites reach the ground. The study will be available in the journal Earth & Planetary Science Letters from April 15. Micrometeorites have always fallen on our planet. These interplanetary dust particles from comets or asteroids are particles of a few tenths to hundredths of a millimetre that have passed ...

Research shows cytonemes distribute Wnt proteins in vertebrate tissue

2021-04-08
Scientists have made a pivotal breakthrough in understanding the way in which cells communicate with each other. A team of international researchers, including experts from the University of Exeter's Living Systems Institute, has identified how signalling pathways of Wnt proteins - which orchestrate and control many cell developmental processes - operate on both molecular and cellular levels. Various mechanisms exist for cells to communicate with each other, and many are essential for development. This information exchange between cells is often based on signalling proteins that activate specific intracellular signalling cascades to control cell behaviour at a distance. Wnt proteins are produced by a relatively small group ...

Health impacts of holocaust linger long after survival

2021-04-08
The damaging effects of life under Nazi rule have long been known with many victims having experienced periods of protracted emotional and physical torture, malnutrition and mass exposure to disease. But recent research from the Hebrew University of Jerusalem show that even for those who survived, their health and mortality continued to be directly impacted long after the end of the Holocaust. The study, led by Drs. Iaroslav Youssim and Hagit Hochner from the School of Public Health at the Faculty of Medicine and published in the American Journal of Epidemiology, investigated mortality rates from ...

LAST 30 PRESS RELEASES:

Individuals with multiple sclerosis face substantially greater risk of hospitalisation and death from COVID-19, despite high rates of vaccination

Study shows obesity in childhood associated with a more than doubling of risk of developing multiple sclerosis in early adulthood

Rice Emerging Scholars Program receives $2.5M NSF grant to boost STEM education

Virtual rehabilitation provides benefits for stroke recovery

Generative AI develops potential new drugs for antibiotic-resistant bacteria

Biofuels could help island nations survive a global catastrophe, study suggests

NJIT research team discovering how fluids behave in nanopores with NSF grant

New study shows association of historical housing discrimination and shortfalls in colon cancer treatment

Social media use may help to empower plastic surgery patients

Q&A: How to train AI when you don't have enough data

Wayne State University researchers uncover potential treatment targets for Zika virus-related eye abnormalities

Discovering Van Gogh in the wild: scientists unveil a new gecko species

Small birds spice up the already diverse diet of spotted hyenas in Namibia

Imaging detects transient “hypoxic pockets” in the mouse brain

Dissolved organic matter could be used to track and improve the health of freshwaters

Indoor air quality standards in public buildings would boost health and economy, say international experts

Positive associations between premenstrual disorders and perinatal depression

New imaging method illuminates oxygen's journey in the brain

Researchers discover key gene for toxic alkaloid in barley

New approach to monitoring freshwater quality can identify sources of pollution, and predict their effects

Bidirectional link between premenstrual disorders and perinatal depression

Cell division quality control ‘stopwatch’ uncovered

Vaccine protects cattle from bovine tuberculosis, may eliminate disease

Andrew Siemion to receive the SETI Institute’s 2024 Drake Award

New study shows how the Crimean-Congo hemorrhagic fever virus enters our cells

Neoadjuvant chemotherapy proves effective for locally advanced penile squamous cell carcinoma

Study flips treatment paradigm in bilateral Wilms tumor, shows resistance to chemotherapy may point toward favorable outcomes

Doctors received approximately $12.1 billion from drug and device makers between 2013-2022

Discovery suggests new strategy against follicular lymphoma

Making the future too bright: how wishful thinking can point us in the wrong direction

[Press-News.org] 'Bug brain soup' expands menu for scientists studying animal brains
By mashing up brains from various insect species, neuroscientists at the University of Arizona were able to count the neurons in individual brains, providing a more meaningful metric than traditional studies measuring brain size or weight.