Can a protein found in a mosquito lead to a better understanding of the workings of our own brains? Prof. Ofer Yizhar and his team in the Weizmann Institute of Science’s Neurobiology Department took a light-sensitive protein derived from mosquitos and used it to devise an improved method for investigating the messages that are passed from neuron to neuron in the brains of mice.

This method, reported today in Neuron, could potentially help scientists solve age-old cerebral mysteries that could pave the way for new and improved therapies to treat neurological and psychiatric conditions.

Yizhar and his lab team develop so-called optogenetic methods – research techniques that allow them to “reverse engineer” the activity of specific brain circuits in order to better understand their function. Optogenetics uses proteins known as rhodopsins to control the activity of neurons in the mouse brain.

Rhodopsins are light-sensing proteins – they are most known for their role in organs like the retina rather than in the dark inner reaches of the body. But the rhodopsins in the brains of Yizhar’s mice enable him to control the activity of specific neurons when he and his team shine a minuscule beam of light into the mouse’s brain. He is especially interested in communication between neurons: What signals are getting passed through the synapses, those gaps over which the brain’s signals move? “We can detect the presence of the various neurotransmitters, but different neurons ‘read’ those neurotransmitters differently,” he says. “Optogenetics enables us to not only see the ‘ink,’ but really to decipher the ‘message’.”

While optogenetic methods have produced a number of breakthrough results in labs around the world in recent years, they can be a bit finicky. In particular, the rhodopsins used for optogenetic studies tend to be imperfect when it comes to controlling the activity of synapses, the tiny junctions between neurons.

Yizhar and a large team of his trainees, including Dr. Mathias Mahn, Dr. Inbar Saraf Sinik and Pritish Patil, believed they could create a better version of the rhodopsins than those currently available. “We decided to look around and see what natural solutions exist out there,” says Yizhar.

And nature, it turns out, contains a multitude of variations on the rhodopsin molecule – not only in animal eyes but also fish, insects, and even mammals carry them in various body parts; some possibly for regulating their circadian cycles, others for purposes as yet unknown. Thus, the team started out with a long list of potential rhodopsin proteins, and their first job involved assessing which ones were most likely to fill their experimental requirements, which primarily included light-gated proteins that are able to modulate synaptic activity. Eventually the researchers winnowed their list down to two – one taken from a pufferfish and one from a mosquito.

It was the mosquito rhodopsin that turned out to be the most suitable. To evaluate the efficacy of the new mosquito-derived tool, the researchers tested their method against a drug that is known to reduce the strength of the communication between neurons in the brain. They found that the interference was just as effective, and much more stable with the mosquito rhodopsin.

More than that: Unlike a conventional drug that affects numerous parts of the brain and is hard to control, the researchers found that since only neurons that produce the mosquito sensor are affected by the light, the modulatory effect on the brain’s synapses can be precisely controlled in both space and time – just by switching the light on or off in specific brain regions. They then validated the utility of the new tool by using it to block the release of the neurotransmitter dopamine on one side of the brain only: Illuminating the hemisphere expressing the mosquito rhodopsin with green light led to a one-sided bias in the behavior of these mice. In other words, they had created a tool that was precise, selective, and controllable.

“One of the major advantages of the mosquito rhodopsin is that it’s bistable – that is, it does not need refreshing – and it is potentially very specific, so that we can control just the precise synapses in which we are interested,” says Yizhar. “This is a very exciting technology, since it will allow us to discover the roles of specific pathways in the brain in a way that was not possible before.

“We think this mosquito protein could open the way to developing a whole family of new optogenetic tools for use in neuroscience research.”

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A new Tel Aviv University study reveals a possible defense mechanism developed by fireflies for protection against bats that might prey on them.

According to the study, fireflies produce strong ultrasonic sounds — soundwaves that the human ear, and more importantly the fireflies themselves, cannot detect. The researchers hypothesize that these sounds are meant for the ears of bats, keeping them away from the poisonous fireflies, and thereby serving as a kind of “musical armor.”

The study was led by Professor Yossi Yovel, Head of TAU’s Sagol School of Neuroscience and a member of the School of Mechanical Engineering and the School of Zoology at the George S. Wise Faculty of Life Sciences. It was conducted in collaboration with the Vietnam Academy of Science and Technology and was published in iScience on March 19, 2021.

Fireflies are known for their unique glow, used as a mating signal. Since their bodies contain poison, the light flashes probably also serve as a warning to potential predators. This signal is also the firefly’s weakness, simply because it makes it an easy target for predators. Bats are among the fireflies’ most prevalent potential predators, and some bats have poor vision, rendering the flashing signal ineffective. This led the researchers to check whether fireflies had some additional layer of protection against bats.

Professor Yovel explains that the idea for this study came up accidentally, during a study that tracked bats’ echolocation. “We were wandering around a tropical forest with microphones capable of recording bats’ high frequencies, when suddenly, we detected unfamiliar sounds at similar frequencies, coming from fireflies,” he recalls.

“In-depth research using high-speed video revealed that the fireflies produce the sound by moving their wings, and that the fireflies themselves can’t hear this frequency. Consequently we hypothesized that the sound is not intended for any internal communication within the species,” adds Ksenia Krivoruchku, the PhD student who led the study.

Following the discovery, Professor Yovel’s team examined three different species of fireflies that are common in Vietnam and one Israeli species, and found that they all produce these unique ultrasonic sounds, but cannot hear them.

Have fireflies developed a defense mechanism specifically for bats? Professor Yovel emphasizes that this claim was not proved in the study, but several features do point to this conclusion. Fireflies themselves can’t hear the sound, while bats can both hear it and use it to find the fireflies, so it’s more likely that it serves as a warning signal. Krivoruochku adds that the discovery of ultrasonic sounds in fireflies is in itself an important contribution to the study of predator-prey relations.

“The idea of warning signals that the sender itself cannot detect is known from the world of plants but is quite rare among animals,” Krivoruochku concludes. “Our discovery of the ‘musical battle’ between fireflies and bats may pave the way for further research, and possibly the discovery of a new defense mechanism developed by animals against potential predators.”

The post Fireflies use music as armor against bats appeared first on Green Prophet.

In recent years, hummus has become a pop culture food phenomenon, drawing praises from dieticians for the health benefits and chefs for the flavor.

However, the core ingredient, the chickpea, has had its production threatened. The chickpea has played a significant role in the vegetarian diet for thousands of years. It is high in protein and rich in important carbohydrates and minerals. And vegans love it. 

Grown in the Pacific Northwest and Northern Plains of the United States, the chickpea has an integral role in the agriculture systems of these regions. Recently this role has been threatened by a soil-born water mold, Pythium ultimum. 

George Vandemark and his team have worked to improve chickpea varieties and develop new ways to control disease in legumes. Their research was recently shared in Crop Science, a publication of the Crop Science Society of America.

“For over 30 years, common pathogens in chickpeas and other legumes have been controlled by fungicides,” says Vandemark. “We discovered this approach was not working effectively when one of my coworkers visited a field where seedlings had not emerged.”

The planted seeds died shortly after they started to germinate. As the seed grew to the top of the soil, the disease attacked the plant and killed it.

To identify the cause, researchers isolated the chickpea seeds in the soil. They discovered that the pathogen P. ultimum developed resistance to fungicide. This resistance allowed the mold to infect the plant.

“Our approach looked at two different types of chickpeas – kabuli and desi,” says Vandemark. “The kabuli chickpea is almost exclusively grown in the United States because of the large export market.”

Time to start planting small Desi chickpeas

Kabuli chickpeas are larger, have a clear or light beige seed coat, and are typically canned and used to make hummus. Desi, believed to have originated in Turkey, is smaller, has a colored seed coat, and is used for making stews.

If you ask around famous hummus chefs in Israel, for instance, they will tell you to use only the smaller Desi variety. Get the ultimate hummus recipe here. Or scroll down to the bottom of the post for it. 

The researchers examined different lines of the chickpea to identify natural sources of resistance to P. ultimum.

The most popular varieties of chickpea grown in the United States were susceptible to the disease. The team did discover other chickpea varieties that showed resistance to the soil-born mold.

“We identified many desi chickpeas that were resistant to the pathogen,” said Vandemark. “Luckily, several kabuli also displayed intermediate levels of resistance.”

These resistant chickpea varieties excited the researchers because they produce chickpeas that look similar to what consumers are used to.

“These traits are not ones we want to lose,” said Vandemark. “Consumers expect the kabuli type chickpea to come from the United States. The lines we identified with resistance to the disease have the shape and seed color that are desirable.”

With this discovery, the research team is using the resistant plants to breed new kabuli varieties. The resistance chickpeas are crossed with current commercial varieties. This will develop a type that is more resistant to the disease.

“Moving forward, this will lead to new chickpea varieties with improved resistance to P. ultimum,” explains Vandemark. “This research will also lead to new methods for controlling diseases that rely less on fungicides and more on genetic resistance.”

From this research, scientists can gain a better understanding of disease and disease resistance. This will push researchers to use plant breeding as a means to combat diseases, rather than synthetic chemicals.

“P. ultimum has a broad range of hosts,” says Vandemark. “While we looked at chickpeas, it can affect small grains like wheat and other legumes like soybeans. The chickpea has a small genome size, making it easier to examine.”

Future researchers can build upon this research to examine potential disease resistance to P. ultimum in other crops. Naturally controlling the disease using genetics and breeding can lead to a more sustainable production system.  

George Vandemark is a researcher for the United States Department of Agriculture’s Agricultural Research Service. This work was supported by the United States Department of Agriculture and the USA Dry Pea and Lentil Council.

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Maxim’s Hummus Recipe

Ingredients
• 6.5 pounds of small-sized dried chickpeas (Desi chickpeas)
• 1 tablespoon baking soda
• 1 tablespoon baking powder
• 2 tablespoons of salt
• 2 tablespoons of lemon salt
• Half measure of tehina (Amount of tehina equals half the volume of    cooked chickpeas)
• Water
• Olive oil to garnish

Take 6.5 pounds of dried chickpeas and soak them overnight in cold water, along with baking soda and baking powder. The next morning clean the chickpeas in running water. Drain the water and remove any small stones.

Adding cold water to cover the chickpeas and then a double amount, vigorously boil the chickpeas in a large pot. After reaching boiling point, turn down heat, and simmer for 3 hours with a lid, until the chickpeas are soft.

When done, strain the chickpeas, and set aside until cold. When cold, put into a food processor, adding raw tehina – about half the volume of the cooked chickpeas. Add in salt, lemon salt, and enough tablespoons of cold water to achieve a thick, but smooth consistency. Spread the hummus on a plate, and garnish with olive oil.

“That’s it. Now you will have lovely hummus”, says Tony.

And a lot of it. Divide the recipe in half if you want a lot less.

The post Digging into chickpea family for less pesticides in the United States appeared first on Green Prophet.

Fears of global warming and its impact on our environment have left scientists scrambling to decrease levels of atmospheric carbon we humans produce. But Tel Aviv University researchers are doing their part to reduce humanity’s carbon footprint by successfully growing forests in the most unlikely place — deep in Israel’s Arava Desert.

With environmental “extras” such as a local plant species, recycled sewage water unsuitable for agriculture, and arid lands unusable for crops, a group of researchers including Profs. Amram Eshel and Aviah Zilberstein have discovered a winning combination.

In many parts of the world, including areas of India, central Asia and the Sahara desert, their new crop of plants would be not only viable in difficult terrain, but valuable in terms of carbon reduction. These standing crops, grown on land once considered barren, can soak up carbon dioxide from the atmosphere and convert it into oxygen.

Their research is soon to be published in the European Journal of Plant Science and Biotechnology.

Though maintaining our current forests is a necessary initiative, Prof. Eshel says, it is not enough to off-set human carbon output. In their quest to create forests that diminish carbon dioxide in the atmosphere, many countries have been converting fertile agricultural lands into forests.

But TAU researchers believed that encouraging growth on a piece of land that was traditionally barren, such as desert land, was a step in a better direction.

“When you take the overall carbon balance of converting agricultural land and freshwater into energy products, you may not gain that much,” says Prof. Eshel. “You’re investing a lot of energy in the process itself, thus releasing a lot of carbon into the atmosphere.”

To conserve fresh water, the researchers used water considered of low quality, such as recycled sewage water and salt water that was the by-product of inland desalination plants. The final piece of the puzzle was to find a plant hearty enough to successfully grow in the desert.

The researchers turned to Tamarix, a botanical genus that includes salt cedar trees and is indigenous to the old-world deserts. Some 150 different varieties of the botanical genus were used, grown in both a common garden setting and in densities that mimicked commercial crops.

With the first harvest of trees just last summer, researchers have much to process, including analyzing the amount of carbon dioxide the crops have successfully captured from the atmosphere. The answers will determine how much carbon such a crop can offset.

A source for biofuel?

The cut trees themselves might also be used as a source of renewable energy. These “biomass” or “biofuel” crops, derived from natural crops, could help to reduce dependence on traditional fossil fuels such as coal. But the question of where to grow crops dedicated to fuel production had to be addressed, since converting agricultural land could have the side effect of creating food shortages.

Arid and previously unused desert lands provide an ideal solution, Prof. Eshel says. To make his approach economically feasible, much more land would be needed than Israel can provide. But similar tracts of land, such as the Sahara Desert, are big enough to grow these types of crops on a larger scale. He adds that what has been done in the Israeli desert can be replicated elsewhere to great effect.

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