University of New Mexico

DO GUT BACTERIA RULE OUR MINDS?

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It sounds like science fiction, but it seems that bacteria within us — which outnumber our own cells about 100-fold — may very well be affecting both our cravings and moods to get us to eat what they want, and often are driving us toward obesity.

In an article published this week in the journal BioEssays, researchers from UC San Francisco, Arizona State University and University of New Mexico concluded from a review of the recent scientific literature that microbes influence human eating behavior and dietary choices to favor consumption of the particular nutrients they grow best on, rather than simply passively living off whatever nutrients we choose to send their way.

Bacterial species vary in the nutrients they need. Some prefer fat, and others sugar, for instance. But they not only vie with each other for food and to retain a niche within their ecosystem — our digestive tracts — they also often have different aims than we do when it comes to our own actions, according to senior author Athena Aktipis, PhD, co-founder of the Center for Evolution and Cancer with the Helen Diller Family Comprehensive Cancer Center at UCSF.

While it is unclear exactly how this occurs, the authors believe this diverse community of microbes, collectively known as the gut microbiome, may influence our decisions by releasing signaling molecules into our gut. Because the gut is linked to the immune system, the endocrine system and the nervous system, those signals could influence our physiologic and behavioral responses.

“Bacteria within the gut are manipulative,” said Carlo Maley, PhD, director of the UCSF Center for Evolution and Cancer and corresponding author on the paper. “There is a diversity of interests represented in the microbiome, some aligned with our own dietary goals, and others not.

Fortunately, it’s a two-way street. We can influence the compatibility of these microscopic, single-celled houseguests by deliberating altering what we ingest, Maley said, with measurable changes in the microbiome within 24 hours of diet change.

Our diets have a huge impact on microbial populations in the gut,” Maley said. “It’s a whole ecosystem, and it’s evolving on the time scale of minutes.”

There are even specialized bacteria that digest seaweed, found in humans in Japan, where seaweed is popular in the diet.

Research suggests that gut bacteria may be affecting our eating decisions in part by acting through the vagus nerve, which connects 100 million nerve cells from the digestive tract to the base of the brain.

“Microbes have the capacity to manipulate behavior and mood through altering the neural signals in the vagus nerve, changing taste receptors, producing toxins to make us feel bad, and releasing chemical rewards to make us feel good,” said Aktipis, who is currently in the Arizona State University Department of Psychology.

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In mice, certain strains of bacteria increase anxious behavior. In humans, one clinical trial found that drinking a probiotic containing Lactobacillus casei improved mood in those who were feeling the lowest.

Maley, Aktipis and first author Joe Alcock, MD, from the Department of Emergency Medicine at the University of New Mexico, proposed further research to test the sway microbes hold over us. For example, would transplantation into the gut of the bacteria requiring a nutrient from seaweed lead the human host to eat more seaweed?

The speed with which the microbiome can change may be encouraging to those who seek to improve health by altering microbial populations. This may be accomplished through food and supplement choices, by ingesting specific bacterial species in the form of probiotics, or by killing targeted species with antibiotics. Optimizing the balance of power among bacterial species in our gut might allow us to lead less obese and healthier lives, according to the authors.

“Because microbiota are easily manipulatable by prebiotics, probiotics, antibiotics, fecal transplants, and dietary changes, altering our microbiota offers a tractable approach to otherwise intractable problems of obesity and unhealthy eating,” the authors wrote.

The authors met and first discussed the ideas in the BioEssays paper at a summer school conference on evolutionary medicine two years ago. Aktipis, who is an evolutionary biologist and a psychologist, was drawn to the opportunity to investigate the complex interaction of the different fitness interests of microbes and their hosts and how those play out in our daily lives. Maley, a computer scientist and evolutionary biologist, had established a career studying how tumor cells arise from normal cells and evolve over time through natural selection within the body as cancer progresses.

In fact, the evolution of tumors and of bacterial communities are linked, points out Aktipis, who said some of the bacteria that normally live within us cause stomach cancer and perhaps other cancers.

“Targeting the microbiome could open up possibilities for preventing a variety of disease from obesity and diabetes to cancers of the gastro-intestinal tract. We are only beginning to scratch the surface of the importance of the microbiome for human health,” she said.

Biologists create ‘zombie’ cells.

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‘Zombie’ cells are created in lab… and they outperform their living counterparts

It may sound like something from a science fiction film, but scientists say they have created ‘zombie cells’ – that continue to work after they are dead.

But unlike the walking dead of Hollywood, these cells actually perform some functions better than when they were alive.

Scientists say by coating organic cells in silicic acid they are able to withstand far greater temperatures and pressures than flesh.

The zombie cells were created by biologists at Sandia National Laboratories and the University of New Mexico.

The process of cell zombification is relatively simple: scientists coat a living cell with silicon to replicate its structure to near perfection.

As it turns out, the silicon-coated cells perform tasks more efficiently after the living cell has died. A horde of billions of hard-working cell zombies would have many applications in commercial and research fields from the tiny to the huge. The process also allows scientists to create copies of cells accurate down to the groves in the DNA.

The living cell essentially serves as a mold for the silicon. The silicon zombie cells can withstand a much wider temperature and pressure range than flesh and it seems that they can perform certain functions better than the living originals.

“Take some free-floating mammalian cells, put them in a Petri dish and add silicic acid,” Michael Hess, Digital Communications Specialist for Office of Public Affairs of the United States Department of Energy, writes of the process. “The silicic acid, for reasons still partially unclear, enters without clogging and in effect embalms every organelle in the cell from the micro- to the nanometer scale.”

For those looking for a science fiction approximation, these silicon cell copies might be less zombie and more of a clone/robot blend.

“By heating the silica to relatively low heat (400 C), the organic material of the cell — its protein — evaporates and leaves the silica in a kind of three-dimensional Madame Tussauds wax replica of a formerly living being,” Hess writes. “The difference is that instead of modeling the face, say, of a famous criminal, the hardened silica-based cells display internal mineralized structures with intricate features ranging from nano- to millimeter-length scales.”

“King Tut was mummified,” said Sandia materials scientist Bryan Kaehr, the lead researcher of the project, “to approximately resemble his living self, but the process took place without mineralization. Our zombie cells bridge chemistry and biology to create forms that not only near-perfectly resemble their past selves, but can do future work.”

Screenwriting inspiration aside, there are important reasons the researchers experimented with copying cells. The hardworking silicon zombies could help out in industries dealing with fuel cells and decontamination.

 

Source: http://csglobe.com

 

 

 

Brain scans of rappers shed light on creativity.

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Functional magnetic resonance imaging shows what happens in the brain during improvisation.

Rappers making up rhymes on the fly while in a brain scanner have provided an insight into the creative process.

Freestyle rapping — in which a performer improvises a song by stringing together unrehearsed lyrics — is a highly prized skill in hip hop. But instead of watching a performance in a club, Siyuan Liu and Allen Braun, neuroscientists at the US National Institute on Deafness and Other Communication Disorders in Bethesda, Maryland, and their colleagues had 12 rappers freestyle in a functional magnetic resonance imaging (fMRI) machine.

The artists also recited a set of memorized lyrics chosen by the researchers. By comparing the brain scans from rappers taken during freestyling to those taken during the rote recitation, they were able to see which areas of the brain are used during improvisation. The study is published today in Scientific Reports1.

The results parallel previous imaging studies in which Braun and Charles Limb, a doctor and musician at Johns Hopkins University in Baltimore, Maryland, looked at fMRI scans from jazz musicians2. Both sets of artists showed lower activity in part of their frontal lobes called the dorsolateral prefrontal cortex during improvisation, and increased activity in another area, called the medial prefrontal cortex. The areas that were found to be ‘deactivated’ are associated with regulating other brain functions.

“We think what we see is a relaxation of ‘executive functions’ to allow more natural de-focused attention and uncensored processes to occur that might be the hallmark of creativity,” says Braun.

He adds that this suggestion is “a little bit controversial in the literature”, because some studies have found activation of the dorsolateral prefrontal cortex in creative behaviour. He suggests that the discrepancy might have to do with the tasks chosen to represent creativity. In studies that found activation, the activities — such as those that require recall — may actually be less creative.

“We try to stick with more natural creative processing, and when we do that we see this decrease in the dorsal lateral regions,” says Braun.

Pump down the volume

Rex Jung, a clinical neuropsychologist at the University of New Mexico in Albuquerque, has also studied the link between brain structures and creativity, finding an inverse relationship between the volume of some frontal lobe structures and creativity3. “Some of our results imply this downregulation of the frontal lobes in service of creative cognition. [The latest paper] really appears to pull it all together,” he says. “I’m excited about the findings.”

Jung says that this downregulation is likely to apply in other, non-musical areas of creativity — including science.

The findings also suggest an explanation for why new music might seem to the artist to be created of its own accord. With less involvement by the lateral prefrontal regions of the brain, the performance could seem to its creator to have “occurred outside of conscious awareness”, the authors write.

Michael Eagle, a study co-author who raps under the name Open Mike Eagle, agrees: “That’s kind of the nature of that type of improvisation. Even as people who do it, we’re not 100% sure of where we’re getting improvisation from.”

Liu says that the researchers are now working on problems they were unable to explore with freestylers — such as what happens after the initial burst of creative inspiration.

“We think that the creative process may be divided into two phases,” he says. “The first is the spontaneous improvisatory phase. In this phase you can generate novel ideas. We think there is a second phase, some kind of creative processing [in] revision.”

The researchers would also like to look at how creativity differs between experts and amateurs of a similar artistic ilk to freestylers: poets and storytellers.

Watch the video on youtube.URL: http://www.youtube.com/watch?v=LmreCiyV-Kc&feature=player_embedded

Source: Nature