mice – Artifex.News https://artifex.news Stay Connected. Stay Informed. Fri, 22 May 2026 11:45:00 +0000 en-US hourly 1 https://wordpress.org/?v=7.0 https://artifex.news/wp-content/uploads/2026/05/cropped-cropped-app-logo-32x32.png mice – Artifex.News https://artifex.news 32 32 Fake memory implanted in mice with a beam of light https://artifex.news/article60423116-ece/ Fri, 22 May 2026 11:45:00 +0000 https://artifex.news/article60423116-ece/ Read More “Fake memory implanted in mice with a beam of light” »

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If you’ve ever been frustrated by erratic memories, spare a thought for the mice involved in a study published in the journal >Science . Researchers have been able to consistently create a “false memory”, making a mouse fearful of a place it has no reason to fear. The memory was implanted by shining blue light into the mouse’s brain, which triggered a carefully chosen group of neurons. 

The researchers used >optogenetics , a technique that allows precise control of brain circuits. The control is achieved by expressing proteins that act as switches in particular types of brain cell. These switches are channels that, when struck by a particular colour of light, allow charged particles into or out of the neurons, which will either activate or silence them. 

Susumu Tonegawa of the Massachusetts Institute of Technology and his colleagues wanted to find out whether they could create a new, negative association by flipping the switch on an old, neutral memory while giving the mouse a negative experience. Would this lead the mouse to be scared of the old memory?

To find out, Tonegawa’s group needed to identify the scattered set of neurons storing the first memory and install an optogenetic on-switch. They figured out how to do that >last year

The neurons that record new information are located in a particular corner of the hippocampus, the coiled brain structure that we know is crucial for memory formation. That area, the dentate gyrus, can be targeted with a virus, which acts as a courier that delivers genes that encode the protein switch. The difficult part is to deliver the virus only to cells that are storing the memory of choice. Tonegawa and his colleagues found that they could target those neurons that are busier than usual.

Armed with this discovery, they installed the optogenetic trigger in the neurons that were especially busy while a mouse got to know a new environment (we’ll call that Place A). The next day, in a different environment, they gave the mouse small electric shocks while triggering the memory of Place A using light. After that, even though it never had a negative experience in Place A itself, the mouse froze when it was returned there.

In another experiment, mice were given the same memory-shock treatment and then offered a choice between Place A and somewhere else. The mice avoided Place A. A group of mice that had the same virus inserted into a different part of the hippocampus was unaffected and just as happy in Place A as anywhere else. The artificial fear specifically required an alteration of the dentate gyrus.

Admittedly, “Uh-oh, Place A!” is not on the same level as the elaborate, special effects-laden falsehoods that featured in Christopher Nolan’s >Inception . We cannot script new memories. The best recent fictional analogy for these experiments is one for fans of the >Hunger Games trilogy: in the “hijacking” process, the Capitol authorities render existing memories traumatic by pairing them with doses of hallucinogenic poison. 

Of course, we will never know exactly what the mouse remembers. The artificial firing of those selected cells is unlikely to conjure the full experience of being back in Place A, though it is certainly enough to influence behaviour. The mice returned to Place A after the “hijacking” spent about a third of their time frozen; other mice only froze for about 10% of the time.

Hapless laboratory animals have been enduring this type of behavioural testing for >nearly a century . It is no surprise that we can train a mouse to dislike a room. But to do so while the mouse is in another room entirely, by triggering a memory with light? Science like this was impossible a decade ago. 

When Francis Crick, famous for revealing the structure of DNA, floated the notion of light-activated neurons >in 1999 he called it “far-fetched”. Now, just over a decade later, we see new experiments every week that drive or silence different circuits with light, affecting cognition and mimicking or mending the processes underlying mental illness. 

This paper offers a relatively modest advance on previous work from >Tonegawa’s own team , and other studies in >mice and >fruit flies . But it illustrates the power of a technique that has the global neuroscience community enthralled. 

Optogenetics has brought surprising technical advances and changed the way many neuroscientists work. For me, however, there remains inherent wonder in the fact that we can control brain cells – if not create memories – with light.

Jonathan Webb does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations. 

This article was originally published at >The Conversation . Read the >original article



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Turtles, Mice, Scorpions May Become More Common In Major US Cities: Study https://artifex.news/turtles-mice-scorpions-may-become-more-common-in-major-us-cities-study-5324511/ Thu, 28 Mar 2024 01:39:03 +0000 https://artifex.news/turtles-mice-scorpions-may-become-more-common-in-major-us-cities-study-5324511/ Read More “Turtles, Mice, Scorpions May Become More Common In Major US Cities: Study” »

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The prevalence of turtles, scorpions and mice is broadly expected to increase.

Peregrine falcons perched atop towering skyscrapers. Coyotes caught on camera playing in someone’s backyard. The pale green wings of a cabbage white butterfly perched on a flower blossom. Urban areas are awash in wildlife that faces growing pressures due to climate change, according to a study published today in PLOS ONE. The research, which looked at climate impacts on everything from mammals to insects in 60 of the most populous cities across the US and Canada, found that a warming world is moving many animals out of their historical geographic ranges and into new ones.

“Within a few years, the animals that you feed at your bird feeder might look very different,” said Alessandro Filazzola, the study’s lead author, who completed the research while he was a postdoctoral fellow at the University of Toronto Mississauga’s Centre for Urban Environments.

Filazzola and his team leveraged data from the Global Biodiversity Information Facility, which pulls data from community science apps like iNaturalist and eBird, to estimate roughly how many species are currently present in urban areas. They then paired that information with United Nations climate projections known as shared socioeconomic pathways, or SSPs. The researchers looked at what happened to wildlife under three different scenarios, from moderate warming of 1.4C over pre-industrial levels by 2100 – in line with the Paris Climate Agreement – to a mid-range warming of 3.6C to the most extreme possible warming of 4.4C with continued development of fossil fuels. So far the planet has warmed by 1.3C over pre-industrial levels.

“We saw that a lot of cities are seeing large changes,” said Filazzola. “Many species are moving in and many species are moving out.”

Among the broad trends identified in the study: Most vertebrates, including loons, canids (which includes coyotes) and amphibians will become less common across the cities studied. So too will the seemingly ubiquitous earthworm, though only one species of earthworm showed up in the data. The prevalence of turtles, scorpions and (in an exception to the vertebrates decline) mice, meanwhile, is broadly expected to increase.

Add image caption here

“Ecologists are already very aware that species ranges are shifting with a changing climate, so it’s not surprising that this is also happening to a significant extent in cities,” said Carly Ziter, an assistant professor of biology at Concordia University, who was not involved in the study. “But it’s not something that I’ve seen as much attention paid to.”

Even under the lowest warming scenario, researchers found that the cities studied can expect at least 50 new species to move in and 40 to move out, though the turnover isn’t evenly distributed. Toronto, for example, is expected to lose between 40 and 195 of its estimated 888 species, but could gain between 159 and 360 new species by 2100 (where higher rates of warming are associated with both increased species loss and gains). Quebec City and Omaha, Nebraska are also among the cities predicted to have the largest increase in new species while experiencing the least amount of loss. In contrast, places like Atlanta, San Antonio and Austin are expected to lose more species than they gain.

It’s not just wildlife in jeopardy: Atlanta, for example, is on track to lose 13.5% of tree species by the end of this century, the study notes.

The cities with the lowest levels of expected species turnover are in the arid Southwest and include Las Vegas as well as Mesa and Tucson in Arizona. While climate change will likely make those places even drier, researchers suspect those ecosystems are already resilient to the encroaching changes.

Filazzola cautions that his study is a model study and, as such, has limitations. While the researchers only looked at climate as a factor, other factors such as species interaction are not captured by the model and could impact outcomes. But he hopes that the findings will encourage other researchers to follow this line of inquiry.

Species turnover isn’t just an important indicator of climate impacts, Filazzola notes: As animals move from their ecological niche, they can create nuisances for humans. Already, Southern Californians have to deal with a growing mosquito problem as Aedes mosquitoes, a species with a strong preference for biting humans, have moved into the region over the past decade.

Cities are also the site of frequent human-wildlife interactions, including both conflicts and delight. “With this great urban shift, many people will need to re-learn how to interact with the wildlife around them,” Ziter said. “Particular species can also have immense cultural or relational value for people. Even for urban dwellers who might see themselves as separate from nature, I think many people would feel less connected to where they live if familiar species were to disappear from the landscape.”

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

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Turtles, Mice, Scorpions May Become More Common In Major US Cities: Study https://artifex.news/turtles-mice-scorpions-may-become-more-common-in-major-us-cities-study-5324510/ Thu, 28 Mar 2024 01:39:02 +0000 https://artifex.news/turtles-mice-scorpions-may-become-more-common-in-major-us-cities-study-5324510/ Read More “Turtles, Mice, Scorpions May Become More Common In Major US Cities: Study” »

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The prevalence of turtles, scorpions and mice is broadly expected to increase.

Peregrine falcons perched atop towering skyscrapers. Coyotes caught on camera playing in someone’s backyard. The pale green wings of a cabbage white butterfly perched on a flower blossom. Urban areas are awash in wildlife that faces growing pressures due to climate change, according to a study published today in PLOS ONE. The research, which looked at climate impacts on everything from mammals to insects in 60 of the most populous cities across the US and Canada, found that a warming world is moving many animals out of their historical geographic ranges and into new ones.

“Within a few years, the animals that you feed at your bird feeder might look very different,” said Alessandro Filazzola, the study’s lead author, who completed the research while he was a postdoctoral fellow at the University of Toronto Mississauga’s Centre for Urban Environments.

Filazzola and his team leveraged data from the Global Biodiversity Information Facility, which pulls data from community science apps like iNaturalist and eBird, to estimate roughly how many species are currently present in urban areas. They then paired that information with United Nations climate projections known as shared socioeconomic pathways, or SSPs. The researchers looked at what happened to wildlife under three different scenarios, from moderate warming of 1.4C over pre-industrial levels by 2100 – in line with the Paris Climate Agreement – to a mid-range warming of 3.6C to the most extreme possible warming of 4.4C with continued development of fossil fuels. So far the planet has warmed by 1.3C over pre-industrial levels.

“We saw that a lot of cities are seeing large changes,” said Filazzola. “Many species are moving in and many species are moving out.”

Among the broad trends identified in the study: Most vertebrates, including loons, canids (which includes coyotes) and amphibians will become less common across the cities studied. So too will the seemingly ubiquitous earthworm, though only one species of earthworm showed up in the data. The prevalence of turtles, scorpions and (in an exception to the vertebrates decline) mice, meanwhile, is broadly expected to increase.

Add image caption here

“Ecologists are already very aware that species ranges are shifting with a changing climate, so it’s not surprising that this is also happening to a significant extent in cities,” said Carly Ziter, an assistant professor of biology at Concordia University, who was not involved in the study. “But it’s not something that I’ve seen as much attention paid to.”

Even under the lowest warming scenario, researchers found that the cities studied can expect at least 50 new species to move in and 40 to move out, though the turnover isn’t evenly distributed. Toronto, for example, is expected to lose between 40 and 195 of its estimated 888 species, but could gain between 159 and 360 new species by 2100 (where higher rates of warming are associated with both increased species loss and gains). Quebec City and Omaha, Nebraska are also among the cities predicted to have the largest increase in new species while experiencing the least amount of loss. In contrast, places like Atlanta, San Antonio and Austin are expected to lose more species than they gain.

It’s not just wildlife in jeopardy: Atlanta, for example, is on track to lose 13.5% of tree species by the end of this century, the study notes.

The cities with the lowest levels of expected species turnover are in the arid Southwest and include Las Vegas as well as Mesa and Tucson in Arizona. While climate change will likely make those places even drier, researchers suspect those ecosystems are already resilient to the encroaching changes.

Filazzola cautions that his study is a model study and, as such, has limitations. While the researchers only looked at climate as a factor, other factors such as species interaction are not captured by the model and could impact outcomes. But he hopes that the findings will encourage other researchers to follow this line of inquiry.

Species turnover isn’t just an important indicator of climate impacts, Filazzola notes: As animals move from their ecological niche, they can create nuisances for humans. Already, Southern Californians have to deal with a growing mosquito problem as Aedes mosquitoes, a species with a strong preference for biting humans, have moved into the region over the past decade.

Cities are also the site of frequent human-wildlife interactions, including both conflicts and delight. “With this great urban shift, many people will need to re-learn how to interact with the wildlife around them,” Ziter said. “Particular species can also have immense cultural or relational value for people. Even for urban dwellers who might see themselves as separate from nature, I think many people would feel less connected to where they live if familiar species were to disappear from the landscape.”

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

Waiting for response to load…



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