Tag Archives: biology

Memory is Stored by Turning on Genes in Neurons (to Alter Connection Between Neurons)

I find these kind of stories so interesting. I really have so little understanding of genes. I knew memory had something to do with altering connections between neurons. I had no idea that required turning on many genes in those neurons. Life really is amazing.

Neuroscientists identify a master controller of memory

When you experience a new event, your brain encodes a memory of it by altering the connections between neurons. This requires turning on many genes in those neurons.
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Lin and her colleagues found that Npas4 turns on a series of other genes that modify the brain’s internal wiring by adjusting the strength of synapses, or connections between neurons. “This is a gene that can connect from experience to the eventual changing of the circuit,” says [Yingxi] Lin

So far, the researchers have identified only a few of the genes regulated by Npas4, but they suspect there could be hundreds more. Npas4 is a transcription factor, meaning it controls the copying of other genes into messenger RNA — the genetic material that carries protein-building instructions from the nucleus to the rest of the cell. The MIT experiments showed that Npas4 binds to the activation sites of specific genes and directs an enzyme called RNA polymerase II to start copying them.

“Npas4 is providing this instructive signal,” Ramamoorthi says. “It’s telling the polymerase to land at certain genes, and without it, the polymerase doesn’t know where to go. It’s just floating around in the nucleus.”

When the researchers knocked out the gene for Npas4, they found that mice could not remember their fearful conditioning. They also found that this effect could be produced by knocking out the gene just in the CA3 region of the hippocampus. Knocking it out in other parts of the hippocampus, however, had no effect.

One of the things I aim to do in 2012 is read a few more books on biology and genes. I find it incredible what are genes actually are doing to allow us to live our lives. And I am also very ignorant on the whole area. So hopefully I can have some fun next year learning about it.

Friday Fun: Octopus Walks on Land

Just a fun video for your Friday. Octopuses are really very cool. Not quite as cool as cats but way up there in the realm of cool animals. Octopuses, octopi and octopodes are all acceptable words for plural of octopus?

A few year ago (2008) I posted about another very cool octopus, who liked to juggling fellow aquarium occupants.

I think I will devote more time to learning about octopuses and posting more about them.

Nature Uses Stem Cells from Fetus to Repair Health of Mother

Science shows us so many amazing things. Scientists have learned mice use stem cells from the fetus to repair damage to the mother in the event of things like heart attacks. And there is evidence people do the same thing. Very cool. Nature beat us to the idea of using stem cells to treat health problems.

Helpful Mouse Fetuses Naturally Send Stem Cells to Mom to Fix Her Damaged Heart

When the scientists examined the female mice’s heart tissue two weeks after the heart attacks, they found lots of glowing green tissue—cells that came from the fetus—in the mom’s heart. Mice who had heart attacks had eight times as many cells from the fetus in their hearts as mice who hadn’t had a heart attack did, meaning the high volume of fetal cells was a response to the heart attack.

What’s more, the embryo’s stem cells had differentiated into various types of heart tissue, including cardiomyocytes, the rhythmically contracting muscle cells that produce a heartbeat.
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The hearts of two women who suffered from severe heart weakness were later found to contain cells derived from the cells of a male fetus years after they gave birth to their sons.

The same thing seems to hold true for other organs. When pregnant women have damage in other organs, including the brain, lung, and liver, earlier studies have shown, fetal cells show up there, too.

It makes sense for a fetus to try and aid the mother but it is amazing the evolution found such solutions. Given how many challenges the fetus creates for the mother giving some benefits can help increase the odds of a health birth.

Epigenetic Effects on DNA from Living Conditions in Childhood Persist Well Into Middle Age

Family living conditions in childhood are associated with significant effects in DNA that persist well into middle age, according to new research by Canadian and British scientists.

The team, based at McGill University in Montreal, University of British Columbia in Vancouver and the UCL Institute of Child Health in London looked for gene methylation associated with social and economic factors in early life. They found clear differences in gene methylation between those brought up in families with very high and very low standards of living. More than twice as many methylation differences were associated with the combined effect of the wealth, housing conditions and occupation of parents (that is, early upbringing) than were associated with the current socio-economic circumstances in adulthood. (1252 differences as opposed to 545).

I find Epigenetics to be a very interesting area. My basic understanding as I grew up was that you inherited your genes. But epigenetics explores how your genes change over time. This has been a very active area of research recently. Your DNA remains the same during your life. But the way those genes are expressed changes.

I don’t know of any research supporting the idea I mention in this example, but, to explain the concept in a simple way: you may carry genes in your DNA for processing food in different ways. If you have very limited diet the way your body reacts could be to express genes that specialize in maximizing the acquisition of nutrition from food. And it could be that your body sets these expressions based on your conditions when young; if later, your diet changes you may have set those genes to be expressed in a certain way. Again this is an example to try and explain the concept, not something where I know of research that supports evidence for this example.

The findings by these universities, were unfortunately published in a closed way. Universities should not support the closing of scientific knowledge. Several universities, that support open science, require open publication of scientific research. It is unfortunate some universities continue to support closed science.

The research could provide major evidence as to why the health disadvantages known to be associated with low socio-economic position can remain for life, despite later improvement in living conditions. The study set out to explore the way early life conditions might become ‘biologically-embedded’ and so continue to influence health, for better or worse, throughout life. The scientists decided to look at DNA methylation, a so-called epigenetic modification that is linked to enduring changes in gene activity and hence potential health risks. (Broadly, methylation of a gene at a significant point in the DNA reduces the activity of the gene.)

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I Always Wanted to be Some Sort of Scientist

A nice simple post by a soon to be Dr. of Genetics and Molecular Biology on what being a scientist is like for her. I like her take, which I think is much more accurate than some of the generalities people use. The main reason people (men or women) become scientists because they want to be scientists.

Photo the almost-Dr. Caitlin

The truth is science requires you to be social. We share ideas, techniques, and equipment. A good scientist knows her limitations and uses someone else’s expertise when her own is not enough. The modern scientist communicates not only through conferences and journals, but also through blogging and Facebook.
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When a non-scientist (usually my parents or some other close relative) asks me about what I do, they inevitably want to tie it back to how I’m curing a disease and saving the world. I am not curing a disease or saving the world.

I study science because it’s cool. I study basic science — asking questions for the purpose of learning the answer. That doesn’t mean what I do isn’t important. Lots of ground-breaking medical advances have been made just because someone asked a question no one else thought to ask.
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To all you ladies fighting the good fight in other fields, keep at it, because the numbers are going up for women with advanced degrees.

I’ve always wanted to be some sort of scientist. When I was in elementary school I wanted to be a paleontologist because dinosaurs are awesome (and so was “Jurassic Park”). When I was 11, I read the Hot Zone and knew I wanted to be a biologist. Though there were times that I flirted with the Dark Side, i.e., medical school, but mostly only because when my teachers figured out I was good at science they said go to medical school. No one even suggested becoming a scientist.

Great stuff. Good Luck, Caitlin.

2011 Nobel Prize in Physiology or Medicine

The Nobel Assembly at Karolinska Institutet has today decided that The Nobel Prize in Physiology or Medicine 2011 shall be divided, with one half jointly to Bruce A. Beutler and Jules A. Hoffmann for their discoveries concerning the activation of innate immunity and the other half to Ralph M. Steinman for his discovery of the dendritic cell and its role in adaptive immunity.

This year’s Nobel Laureates have revolutionized our understanding of the immune system by discovering key principles for its activation.

Scientists have long been searching for the gatekeepers of the immune response by which man and other animals defend themselves against attack by bacteria and other microorganisms. Bruce Beutler and Jules Hoffmann discovered receptor proteins that can recognize such microorganisms and activate innate immunity, the first step in the body’s immune response. Ralph Steinman discovered the dendritic cells of the immune system and their unique capacity to activate and regulate adaptive immunity, the later stage of the immune response during which microorganisms are cleared from the body.

The discoveries of the three Nobel Laureates have revealed how the innate and adaptive phases of the immune response are activated and thereby provided novel insights into disease mechanisms. Their work has opened up new avenues for the development of prevention and therapy against infections, cancer, and inflammatory diseases.

We live in a dangerous world. Pathogenic microorganisms (bacteria, virus, fungi, and parasites) threaten us continuously but we are equipped with powerful defense mechanisms (please see image below). The first line of defense, innate immunity, can destroy invading microorganisms and trigger inflammation that contributes to blocking their assault. If microorganisms break through this defense line, adaptive immunity is called into action. With its T and B cells, it produces antibodies and killer cells that destroy infected cells. After successfully combating the infectious assault, our adaptive immune system maintains an immunologic memory that allows a more rapid and powerful mobilization of defense forces next time the same microorganism attacks. These two defense lines of the immune system provide good protection against infections but they also pose a risk. If the activation threshold is too low, or if endogenous molecules can activate the system, inflammatory disease may follow.

The components of the immune system have been identified step by step during the 20th century. Thanks to a series of discoveries awarded the Nobel Prize, we know, for instance, how antibodies are constructed and how T cells recognize foreign substances. However, until the work of Beutler, Hoffmann and Steinman, the mechanisms triggering the activation of innate immunity and mediating the communication between innate and adaptive immunity remained enigmatic.

Ralph Steinman was awarded the Nobel Prize for his discovery of the dendritic cell and its role in adaptive immunity. He was born in Canada and was a professor at Rockefeller University at the end of his career.

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Bacteria Living Inside Animals Cells

Interesting discussion on the bacteria living inside our cells. For example, many plants have bacteria that get inside the root system and then help fix nitrogen for the plant. Some sea slugs take the chloroplasts from algae they eat and incorporate it themselves, allowing them to get energy from light (photosynthesis): they become photosynthetic slugs.

Adults need science education more than kids do is also a good segment. And I agree strongly that we (as individuals and society) lose a great deal when we fail to help people enjoy learning about science during their whole lives.

I also like the usability of this widget above, where it lets you include the internal links easily into a video.

Gamers Use Foldit to Solve Enzyme Configuration in 3 Weeks That Stumped Scientists for Over a Decade

Gamers have solved the structure of a retrovirus enzyme whose configuration had stumped scientists for more than a decade. The gamers achieved their discovery by playing Foldit, a very cool online game that allows players to collaborate and compete in predicting the structure of protein molecules that I wrote about before: Foldit – the Protein Folding Game. You can download it, play, and help move our understanding forward.

After scientists repeatedly failed to piece together the structure of a protein-cutting enzyme from an AIDS-like virus, they called in the Foldit players. The scientists challenged the gamers to produce an accurate model of the enzyme. They did it in only three weeks.

This class of enzymes, called retroviral proteases, has a critical role in how the AIDS virus matures and proliferates. Intensive research is under way to try to find anti-AIDS drugs that can block these enzymes, but efforts were hampered by not knowing exactly what the retroviral protease molecule looks like.

“We wanted to see if human intuition could succeed where automated methods had failed,” said Dr. Firas Khatib of the University of Washington Department of Biochemistry. Khatib is a researcher in the protein structure lab of Dr. David Baker, professor of biochemistry.

Remarkably, the gamers generated models good enough for the researchers to refine and, within a few days, determine the enzyme’s structure. Equally amazing, surfaces on the molecule stood out as likely targets for drugs to de-active the enzyme.

“These features provide exciting opportunities for the design of retroviral drugs, including AIDS drugs,” wrote the authors of a paper appearing Sept. 18 in Nature Structural & Molecular Biology. The scientists and gamers are listed as co-authors.

This is the first instance that the researchers are aware of in which gamers solved a longstanding scientific problem.

“The focus of the UW Center for Game Sciences,” said director Dr. Zoran Popovic, associate professor of computer science and engineering, “is to solve hard problems in science and education that currently cannot be solved by either people or computers alone.”

The solution of the virus enzyme structure, the researchers said, “indicates the power of online computer games to channel human intuition and three-dimensional pattern matching skills to solve challenging scientific problems.”

With names like Foldit Contenders Group and Foldit Void Crushers Group, the gamer teams were fired up for the task of real-world molecule modeling problems. The online protein folding game captivates thousands of avid players worldwide and engages the general public in scientific discovery.

Direct manipulation tools, as well as assistance from a computer program called Rosetta, encourage participants to configure graphics into a workable protein model. Teams send in their answers, and UW researchers constantly improve the design of the game and its puzzles by analyzing the players’ problem-solving strategies.

Figuring out the shape and misshape of proteins contributes to research on causes of and cures for cancer, Alzheimer’s, immune deficiencies and a host of other disorders, as well as to environmental work on biofuels.

Dr. Seth Cooper, of the UW Department of Computing Science and Engineering, is a co-creator of Foldit and its lead designer and developer. He studies human-computer exploration methods and the co-evolution of games and players.

“People have spatial reasoning skills, something computers are not yet good at,” Cooper said. “Games provide a framework for bringing together the strengths of computers and humans. The results in this week’s paper show that gaming, science and computation can be combined to make advances that were not possible before.”

Games like Foldit are evolving. To piece together the retrovirus enzyme structure, Cooper said, gamers used a new Alignment Tool for the first time to copy parts of know molecules and test their fit in an incomplete model.

According to Popovic, “Foldit shows that a game can turn novices into domain experts capable of producing first-class scientific discoveries. We are currently applying the same approach to change the way math and science are taught in school.”

Amber Pieces Containing Remains from Dinosaurs and Birds Show Feather Evolution

Dinosaur feather evolution trapped in Canadian amber

a study of amber found near Grassy Lake in Alberta – dated from what is known as the Late Cretaceous period – has unearthed a full range of feather structures that demonstrate the progression. “We’re finding two ends of the evolutionary development that had been proposed for feathers trapped in the same amber deposit,” said Ryan McKellar of the University of Alberta, lead author of the report.

The team’s find confirms that the filaments progressed to tufts of filaments from a single origin, called barbs. In later development, some of these barbs can coalesce into a central branch called a rachis. As the structure develops further, further branches of filments form from the rachis.

“We’ve got feathers that look to be little filamentous hair-like feathers, we’ve got the same filaments bound together in clumps, and then we’ve got a series that are for all intents and purposes identical to modern feathers,” Mr McKellar told BBC News.

“We’re catching some that look to be dinosaur feathers and another set that are pretty much dead ringers for modern birds.”
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a picture is emerging that many dinosaurs were not the dull-coloured, reptilian-skinned creatures that they were once thought to be. “If you were to transport yourself back 80 million years to western North America and walk around the forest… so many of the animals would have been feathered,” said Dr Norell.

“We’re getting more and more evidence… that these animals were also brightly coloured, just like birds are today.”

Very cool. Science really is great.

Fun Webcast from WWF: Astonish Me

Made in celebration of the World Wildlife Fund‘s 50th anniversary.