English (United Kingdom)French (Fr)Russian (CIS)Espa
Home Forum Neurohacking The Lab Mainstream Watch

Connexion

Pour acc

Alex
useravatar
User Info

Re: Mainstream Watch

Hi dudes,
This just in: [a tiny trial with only parochial subjects, but encouraging nevertheless! -ed]

Mental, physical exercises produce distinct brain benefits
July 18, 2016 by Shelly Kirkland in Medicine & Health / Neuroscience

Cognitive brain training improves executive function whereas aerobic activity improves memory, according to new Center for BrainHealth research at The University of Texas at Dallas.

The study, published in Frontiers in Human Neuroscience, found that healthy adults who participated in cognitive training demonstrated positive changes in executive function as well as a 7.9 percent increase in global brain flow compared to study counterparts who participated in an aerobic exercise program. The aerobic exercise group showed increases in immediate and delayed memory performance that were not seen in the cognitive training group. The randomized trial is the first to compare cerebral blood flow and cerebrovascular reactivity data obtained via MRI.

"Many adults without dementia experience slow, continuous and significant age-related changes in the brain, specifically in the areas of memory and executive function, such as planning and problem-solving," said Dr. Sandra Bond Chapman, study lead author, founder and chief director of the Center for BrainHealth, and Dee Wyly Distinguished University Professor. "We can lose 1 to 2 percent in global brain blood flow every decade, starting in our 20s. To see almost an 8 percent increase in brain blood flow in the cognitive training group may be seen as regaining decades of brain health since blood flow is linked to neural health."

For the study, 36 sedentary adults ages 56 to 75 years were randomized into either a cognitive training or a physical training group. Each group took part in training three hours per week over 12 weeks.

Neurocognitive, physiological and MRI data were taken before, during and after training. The cognitive group received'SMART' training; a manualized brain training developed at the Center for BrainHealth.

The strategy-based training focuses on three executive functions: strategic attention (prioritizing brain resources); integrative reasoning (synthesizing information at a deeper level); and innovation (encouraging fluid thinking, diverse perspective-taking, and problem-solving). The physical training group completed three 60-minute sessions per week that included five minutes of warmup and cool-down with 50 minutes of either walking on a treadmill or cycling on a stationary bike while maintaining 50 to 75 percent of maximum heart rate.

"Most people tell me that they want a better memory and notice memory changes as they get older," said Dr. Mark D'Esposito, study co-author and professor of neuroscience and psychology, and director of the Henry H. Wheeler Jr. Brain Imaging Center at the Helen Wills Neuroscience Institute at the University of California, Berkeley. "While memory is important, executive functions such as decision-making and the ability to synthesize information are equally, if not more so, but we often take them for granted.

The takeaway: Aerobic activity and reasoning training are both valuable tools that give your brain a boost in different ways."

The research team attributes the global cerebral blood flow gains to concerted mental effort during the reasoning training.

"We believe the reasoning training triggered neural plasticity by engaging the brain networks involved in staying focused on a goal, such as writing a brief business proposal, while continuously adapting to new information, such as feedback from a collaborator," Chapman said.

The aerobic exercise group did not show significant global blood flow gains, but the exercisers with improved memory performance showed higher cerebral blood flow in the bilateral hippocampi, areas underlying memory function and particularly vulnerable to aging and dementia.

"Our research has shown that all brain training protocols do not return equal benefits. When targeting the brain functions that give us a mental edge in daily life, strategy-based programs prevail," Chapman said. "This study highlights the potential to accelerate brain health in healthy adults by adopting lifestyle habits that exercise the mind and body. Future trials are needed to further develop and test neuroprotective programs that unite physical and cognitive training protocols for the highest health returns starting early and continuing into late life."

Dr. Laura DeFina, chief executive officer of the Cooper Institute in Dallas and collaborator on the study, said the findings are encouraging.

"We know that physical activity can lead to improved fitness levels. In our Cooper Center Longitudinal Study population, higher fitness has been shown to result in less all-cause dementia with aging," DeFina said. "The current study highlights the benefit of training both the body and the brain, as both produce observable benefits. The initial findings are encouraging and underscore the need for a multifaceted approach when it comes to brain health."

More information: Sandra B. Chapman et al. Distinct Brain and Behavioral Benefits from Cognitive vs. Physical Training: A Randomized Trial in Aging Adults, Frontiers in Human Neuroscience (2016). DOI: 10.3389/fnhum.2016.00338 


Administrator has disabled public posting
Guest
Guest
useravatar
User Info

Re: Mainstream Watch

Alex wrote:

It never rains but it pours...
and it never.. pour but it floods? heh mrgreen

https://www.statnews.com/2016/07/21/stu … ong-cells/

Let's hope it stops there 'cause we all know what happens after a deluge. roll

A2A

Administrator has disabled public posting
Alex
useravatar
User Info

Re: Mainstream Watch

The renaissance begins

By Christian Jarrett

There’s been a lot of talk of the crisis in psychology. For decades, and often with the best of intentions, researchers have engaged in practices that have made it likely their results are “false positives” or not real. But that was in the past. The crisis is ending. “We do not call the rain that follows a long drought a ‘water crisis’,” write Leif Nelson at UC Berkeley and Joseph Simmons and Uri Simonsohn at the University of Pennsylvania. “We do not call sustained growth following a recession an ‘economic crisis'”.

In their paper, due for publication in the Annual Review of Psychology, the trio observe that had any psychologists been in hibernation for the last seven years, they would not recognise their field today. The full disclosure of methods and data, the pre-registration of studies, the publication of negative findings, and replication attempts – all of which help reduce risk of false positives – have increased immeasurably. “The improvements to our field have been dramatic,” they write. “This is psychology’s renaissance.”

As well giving the field of psychology a pep talk, their paper provides a useful review of how we got to this point, the reasons things are getting better, and the ongoing controversies.

The crisis before the renaissance
Nelson and his colleagues believe that starting in 2011, several key developments led to psychology entering a period of self-reflection about its methods. First, a weird, controversial study was published in a prestigious journal. It applied widely used statistical methods to demonstrate “transparently outlandish” effects (our regrettably gullible coverage at the time: “Dramatic study shows participants are affected by psychological phenomena from the future“).

The same year there were several fraud scandals. There was also Nelson and his colleagues’ own influential paper demonstrating how easy it was to use selective reporting and strategic data analysis to extract a ridiculous positive result from random data (in this case, listening to music was shown to decrease your age). They called this approach p-hacking, which is a reference to the fact that psychologists frequently use a statistic known as the p-value – specifically whether it is below 0.05 – to determine whether their result is statically significant or not. Not long after, a survey of psychology researchers showed that “questionable research practices” indicative of p-hacking were commonplace.

Nelson and his colleagues believe that p-hacking helps explain how for several decades psychologists have used underpowered studies with too few participants, and yet succeeded in publishing countless positive results (a similar problem afflicts neuroscience). “P-hacking has long been the biggest threat to the integrity of our discipline,” they write. Researchers have prodded and pushed their results, dropping participants here, running new trials there, selectively reporting just those conditions that seemed to work. For years, the prevailing ethos was that to succeed you do what you can to extract a positive finding from your experiments.

P-hacking could explain why so many famous findings in psychology have failed to replicate, often when tested under more rigorous conditions. But this is open to debate, and in some cases ill-tempered argument (the authors of past studies that haven’t replicated have sometimes bristled at the suggestion that they did not conduct their studies robustly enough, or that their findings are not real).

Nelson and his colleagues believe all sides can agree that most researchers are honest and well-intentioned. As self-confessed former p-hackers, they write that “p-hacking is not categorised as such by the researcher who is doing it. It is not something that malevolent researchers engage in while laughing maniacally.” Regardless of how frequent p-hacking has been, Nelson et al. hope that everyone recognises that it’s better to reduce p-hacking. Or put differently, that it’s better to do science in a way that reduces the risk of false-positives.

The renaissance begins
Fortunately, a consensus seems to have emerged around this position. Amidst all the drama, a revolution is underway. A key player is the psychologist Brian Nosek at the University of Virginia who helped launch the Open Science Framework, an online platform that makes it easy to share methods and data online, and then in 2013 he co-founded the Center for Open Science (read our coverage of some of the large-scale replication efforts organised by the Center).

Other positive changes include key journals such as Psychological Science and Social Psychological and Personality Science implementing the requirement for researchers to disclose all of their measures and manipulations. Even better, pre-registration of methods (publishing your planned methods and hypotheses before you collect your data) is becoming easier and more widespread (two key sites for this are AsPredicted.org and the Open Science Framework), and an increasing number of journals now publish “registered reports”, a cause championed by psychologist Chris Chambers in the UK.

“We expect that in 3-5 years, published pre-registered experimental psychology studies will be either common or extremely common,” write Nelson et al. Some have complained that pre-registered stifles scientific exploration, but Nelson’s team counter “it does not preclude exploration, but it does communicate to readers that it occurred”.

There has also been a welcome “surge of interest” in replicating previous studies – one of the main ways to uncover and address the possible effects of p-hacking on previously published research (according to the CurateScience database, 96 per cent of over 1000 replication attempts have been conducted since 2011). With regard to the debates that often ensue after a failed replication attempt (such as whether the replication was similar enough to the original), Nelson et al. propose a compromise: “the burden of proof is on the researcher espousing the least plausible claim”.

For instance, if the author of the original finding complains that the replication study took place on a different day of the week (and that’s why it didn’t work), it’s beholden on her or him to demonstrate why day of the week should moderate the effect that they originally claimed to have uncovered. On other hand, if the replicators used an obviously inferior manipulation (e.g. in a study testing the effects of hunger, they used just a few minutes without food to induce hunger), it’s up to them to show that the lack of effect persists when hunger is induced in more robust fashion. “Neutral observers often agree on who has the burden of proof,” write Nelson et al.

Another issue for psychology’s renaissance is how to categorise a replication attempt as a success or failure. In fact, Nelson et al. explain how this is often not straight forward and in many cases it is more fair and accurate to interpret unsuccessful replications as inconclusive.

Ongoing debates
Other issues going forward include finding optimal ways to check the veracity of collections of prior studies, such as through using a statistical technique known as “p-curve analysis”. No one approach is flawless. More also needs to be done to check for innocent errors (which are extremely common) and outright fraud (thankfully rare, although Nelson’s team say that “for every case of fraud that is identified, there are almost certainly may more that are not”).
One of the simplest solutions is simply to require researchers to post their data and materials online. “Public data posting not only allows others to verify the accuracy of the analyses, but also incentivises authors to more carefully avoid errors,” write Nelson and his colleagues.

Some readers may be surprised that Nelson et al. don’t welcome all the efforts at reform in psychology. For instance, many have called for a greater emphasis on meta-analyses, in which the findings from many studies are combined. But Nelson’s group argue that this can make matters worse – for instance, biases in the studies can accumulate rather than cancel each other out. “The end result of a meta-analysis is as strong as the weakest link; if there is some garbage in, there is only garbage out.”
Nelson’s team are also sceptical of those who say psychology should ditch p-value based significance testing for other metrics, such as confidence intervals and Bayesian results. “It is not the [particular] statistic that causes the problem, it is the mindlessness [with which they are relied upon].”

“The Enlightenment is just around the corner”
These are healthy debates and they will continue for years to come. For now though, let’s join Nelson and his co-authors in recognising the positive and welcome changes underway in psychological science. “Practices that promise to increase the integrity of our discipline – replications, disclosure, pre-registration – are orders of magnitude more common than they were just a short time ago. And although they are not yet common enough, it is clear that the Middle Ages are behind us, and the Enlightenment is just around the corner.”

—Psychology’s renaissance [Our coverage is based on an early version of this paper published at SSRN, the final published version may differ]


Administrator has disabled public posting
Alex
useravatar
User Info

Re: Mainstream Watch

Hi dudes,
Latest developments in VR

Experience on Demand: What Virtual Reality Is, How It Works, and What It Can Do Jeremy Bailenson W. W. Norton: 2018.

You strap on the head-mounted display, slip on the gloves, tune your ears to the surround sound — and suddenly you are facing a plank jutting out over an abyss. The depths here are virtual, but not everyone can force themselves to jump.
This is just one program developed by psychologist Jeremy Bailenson to demonstrate the capabilities of virtual reality (VR). As a leading researcher in the field, Bailenson crafts new worlds that feel real, to explore their beneficial uses. In Experience On Demand, he tours the myriad applications that he and others are developing. After a great deal of hype by science-fiction film writers and video-game designers in the 1990s, the technology now finally seems poised for widespread use. Eventually, as Bailenson details, it could transform work, schools, hospitals and more.

Read the rest at Nature
https://www.nature.com/articles/d41586- … n=20180126


Administrator has disabled public posting
Alex
useravatar
User Info

Re: Mainstream Watch

Hi dudes,
It's been a long time since we heard of any progress in uploading. This 'worm thing' took a lot longer than I expected and didn't come from any of the places I suspected would crack it. A nice surprise!

Worm uploaded to a computer and trained to balance a pole

February 6, 2018

Is it a computer program or a living being? At TU Wien (Vienna), the boundaries have become blurred. The neural system of a nematode was translated into computer code – and then the virtual worm was taught amazing tricks.
It is not much to look at: the nematode C. elegans is about one millimetre in length and is a very simple organism. But for science, it is extremely interesting. C. elegans is the only living being whose neural system has been analysed completely. It can be drawn as a circuit diagram or reproduced by computer software, so that the neural activity of the worm is simulated by a computer program.

Such an artificial C. elegans has now been trained at TU Wien (Vienna) to perform a remarkable trick: The computer worm has learned to balance a pole at the tip of its tail.

C. elegans has to get by with only 300 neurons. But they are enough to make sure that the worm can find its way, eat bacteria and react to certain external stimuli. It can, for example, react to a touch on its body. A reflexive response is triggered and the worm squirms away.

This behaviour is determined by the worm's nerve cells and the strength of the connections between them. When this simple reflex network is recreated on a computer, the simulated worm reacts in exactly the same way to a virtual stimulation – not because anybody programmed it to do so, but because this kind of behaviour is hard-wired in its neural network.

"This reflexive response of such a neural circuit, is very similar to the reaction of a control agent balancing a pole," says Ramin Hasani (Institute of Computer Engineering, TU Wien). This is a typical control problem that can be solved quite well by standard controllers. A pole is fixed on its lower end on a moving object, and it is supposed to stay in a vertical position. Whenever it starts tilting, the lower end has to move slightly to keep the pole from tipping over. Much like the worm has to change its direction whenever it is stimulated by a touch, the pole must be moved whenever it tilts.

Mathias Lechner, Radu Grosu and Ramin Hasani wanted to find out whether the neural system of C. elegans, uploaded to a computer, could solve this problem – without adding any nerve cells, just by tuning the strength of the synaptic connections. This basic idea (tuning the connections between nerve cells) is also the characteristic feature of any natural learning process.

A Program without a Programmer
"With the help of reinforcement learning, a method also known as 'learning based on experiment and reward,' the artificial reflex network was trained and optimized on the computer," Mathias Lechner explains. The team succeeded in teaching the virtual nerve system to balance a pole. "The result is a controller, which can solve a standard technology problem – stabilizing a pole, balanced on its tip. But no human being has written even one line of code for this controller, it just emerged by training a biological nerve system," says Radu Grosu.

The team is going to explore the capabilities of such control circuits further. The project raises the question whether there is a fundamental difference between living nerve systems and computer code. Is machine learning and the activity of our brain the same on a fundamental level? At least we can be pretty sure that the simple nematode C. elegans does not care whether it lives as a worm in the ground or as a virtual worm on a computer hard drive.

More information: Worm-level Control through Search-based Reinforcement Learning: https://docs.google.com/viewer?a=v& … YWJiNDI5NA


Administrator has disabled public posting
Alex
useravatar
User Info

Re: Mainstream Watch

Woh, dudes...    :  )

Engineers create most efficient red light-activated optogenetic switch for mammalian cells
March 13, 2018

A team of researchers has developed a light-activated switch that can turn genes on and off in mammalian cells. This is the most efficient so-called "optogenetic switch" activated by red and far-red light that has been successfully designed and tested in animal cells—and it doesn't require the addition of sensing molecules from outside the cells.

The light-activated genetic switch could be used to turn genes on and off in gene therapies; to turn off gene expression in future cancer therapies; and to help track and understand gene function in specific locations in the human body.

The team, led by bioengineers at the University of California San Diego, recently detailed their findings online in ACS Synthetic Biology.

"Being able to control genes deep in the body in a specific location and at a specific time, without adding external elements, is a goal our community has long sought," said Todd Coleman, a professor of bioengineering at the Jacobs School of Engineering at UC San Diego and one of the paper's corresponding authors. "We are controlling genes with the most desirable wavelengths of light."

The researchers' success in building the switch relied on two insights. First, animal cells don't have the machinery to supply electrons to make molecules that would be sensitive to red light. It's the equivalent of having a hair dryer and a power outlet from a foreign country, but no power cord and no power outlet adapter. So researchers led by UC San Diego postdoctoral researcher Phillip Kyriakakis went about building those.

For the power cord, they used bacterial and plant ferredoxin, an iron and sulfur protein that brings about electron transfer in a number of reactions. Ferredoxin exists under a different form in animal cells, which isn't compatible with its plant and bacteria cousin. So an enzyme called Ferredoxin-NADP reductase, or FNR, played the role of outlet adapter.

As a result, the animal cells could now transfer enough electrons from their energy supply to other enzymes that can produce the light-sensitive molecules needed for the light-activated switch.
The second insight was that the system to make light-sensitive molecules needed to be placed in the cell's mitochondria, the cell's energy factory. Combining these two insights, the researchers were able to build a plant system to control genes with red light inside animal cells.

Red light is a safe option to activate genetic switches because it easily passes through the human body. A simple way to demonstrate this is to put your hand over your smart phone's flashlight while it's on. Red light, but not the other colors, will shine through because the body doesn't absorb it. And because it's not absorbed, it can actually pass through tissues harmlessly and reach deep within the body to control genes.

Bioengineers built and programmed a small, compact tabletop device to activate the switch with red and far-red light. The tool allows researchers to control the duration that the light shines, down to the millisecond. It also allows them to target very specific locations. Researchers showed that the genes turned on by the switch remained active for several hours in several mammalian cell lines even after a short light pulse.

The team recently received an internal campus grant to use the method to control gene activation in specific regions of the brain. This would allow them to better understand gene function in a variety of neurological disorders.

The researchers patented the use of ferredoxins and FNR to target the enzymes needed to make light-activated molecules. The technology is available for licensing.
Importantly, insights about how to produce plant molecules in animal cells could also one day enable production of other molecules that can lead to the cultivation of plants that do not need fertilizer and make biofuel production more efficient.

'Efficient synthesis of a photosynthetic pigment in mammalian cells for optogenetics'
https://phys.org/news/2018-03-efficient … y-nwletter

More information: Phillip Kyriakakis et al. Biosynthesis of Orthogonal Molecules Using Ferredoxin and Ferredoxin-NADP+ Reductase Systems Enables Genetically Encoded PhyB Optogenetics, ACS Synthetic Biology (2018). DOI: 10.1021/acssynbio.7b00413


Administrator has disabled public posting
Alex
useravatar
User Info

Re: Mainstream Watch

Book about transhumanism wins Wellcome prize
April 30, 2018

A book that explores the quest to defeat death with technology has won Britain's medically themed Wellcome Book Prize.

Mark O'Connell's "To Be a Machine" beat five other finalists Monday for the prize, which aims to bridge the gap between literature and science.

The writer visited cryonic labs, tech firms and cyborg startups for his non-fiction exploration of transhumanism, which seeks (among many other aims)to overcome human frailties by merging people and machines.

Artist and writer Edmund de Waal, who chaired the judging panel, said O'Connell's book was "a passionate, entertaining and cogent examination of those who would choose to live forever."


Administrator has disabled public posting
Robert
useravatar
User Info

Re: Mainstream Watch

more optogenetics research.
I don't have access to the paper,https://www.cell.com/neuron/fulltext/S0 … )30019-9
but the article sounds intriguing.




Scientists Have Identified The Physical Source of Anxiety in The Brain

And they can control it with light.
13 MAY 2018


We're not wired to feel safe all the time, but maybe one day we could be.

A recent study investigating the neurological basis of anxiety in the brain has identified 'anxiety cells' located in the hippocampus – which not only regulate anxious behaviour but can be controlled by a beam of light.

The findings, so far demonstrated in experiments with lab mice, could offer a ray of hope for the millions of people worldwide who experience anxiety disorders (including almost one in five adults in the US), by leading to new drugs that silence these anxiety-controlling neurons.

"We wanted to understand where the emotional information that goes into the feeling of anxiety is encoded within the brain," says one of the researchers, neuroscientist Mazen Kheirbek from the University of California, San Francisco.

To find out, the team used a technique called calcium imaging, inserting miniature microscopes into the brains of lab mice to record the activity of cells in the hippocampus as the animals made their way around their enclosures.

These weren't just any ordinary cages, either.

The team built special mazes where some paths led to open spaces and elevated platforms – exposed environments known to induce anxiety in mice, due to increased vulnerability to predators.

Away from the safety of walls, something went off in the mice's heads – with the researchers observing cells in a part of the hippocampus called ventral CA1 (vCA1) firing up, and the more anxious the mice behaved, the greater the neuron activity became.

"We call these anxiety cells because they only fire when the animals are in places that are innately frightening to them," explains senior researcher Rene Hen from Columbia University.

The output of these cells was traced to the hypothalamus, a region of the brain that – among other things – regulates the hormones that controls emotions.

Because this same regulation process operates in people, too – not just lab mice exposed to anxiety-inducing labyrinths – the researchers hypothesise that the anxiety neurons themselves could be a part of human biology, too.

"Now that we've found these cells in the hippocampus, it opens up new areas for exploring treatment ideas that we didn't know existed before," says one of the team, Jessica Jimenez from Columbia University's Vagelos College of Physicians & Surgeons.

Even more exciting is that we've already figured out a way of controlling these anxiety cells – in mice at least – to the extent it actually changes the animals' observable behaviour.

Using a technique called optogenetics to shine a beam of light onto the cells in the vCA1 region, the researchers were able to effectively silence the anxiety cells and prompt confident, anxiety-free activity in the mice.

"If we turn down this activity, will the animals become less anxious?" Kheirbek told NPR.

"What we found was that they did become less anxious. They actually tended to want to explore the open arms of the maze even more."

This control switch didn't just work one way.

By changing the light settings, the researchers were also able to enhance the activity of the anxiety cells, making the animals quiver even when safely ensconced in enclosed, walled surroundings – not that the team necessarily thinks vCA1 is the only brain region involved here.

"These cells are probably just one part of an extended circuit by which the animal learns about anxiety-related information," Kheirbek told NPR, highlighting other neural cells justify additional study too.

In any case, the next steps will be to find out whether the same control switch is what regulates human anxiety – and based on what we know about the brain similarities with mice, it seems plausible.

If that pans out, these results could open a big new research lead into ways to treat various anxiety conditions.

And that's something we should all be grateful for.

"We have a target," Kheirbek explained to The Mercury News. "A very early way to think about new drugs."

The findings were reported in Neuron.


Administrator has disabled public posting
Scalino
useravatar
User Info

Re: Mainstream Watch

Alex wrote:

Woh, dudes...    :  )

Engineers create most efficient red light-activated optogenetic switch for mammalian cells
March 13, 2018
...
wow! hadn't seen that one, I don't think most people realize exactly what that implies for the near future... smile


Administrator has disabled public posting
Alex
useravatar
User Info

Re: Mainstream Watch

Bit of an updare:

December 5, 2018, Frontiers

By enabling super-fast remote control of specific cells, light-activated proteins allow researchers to study the function of individual neurons within a large network—even an entire brain. Now one of the pioneers of 'optogenetics' and colleagues have created two new tools—protein pores which when illuminated allow Ca2+ into cells or K+ out—for switching neurons on or off using light. Published in Frontiers in Neuroscience, their study shows that these synthetic 'ion channels' can be used to control specific neurons, even in live animals.

Controlling neurons with light
Georg Nagel's research group at the University of Würzburg combines DNA from across the kingdoms of life—from aquatic heat-loving bacteria to cows—to create hybrid ion channels that open when animated by light. Ion channels enable excitable cells like neurons to generate and transport electrical signals, by allowing charged ions to pass in and out through the cell surface.
"By engineering specific neurons to express these channels, we can switch them on and off using light," explains Nagel.
Optogenetics was first born when Nagel and longtime collaborator Peter Hegemann isolated from green algae two light-activated channels called 'channelrhodopsins'. These allow positively-charged ions—particularly Na+ - to enter and excite neurons.
Following the success of channelrhodopsins, another natural optogenetic ion channel 'halorhodopsin' was developed for use as a neuron silencer. When illuminated, halorhodopsin inhibits neuronal signals with light-induced inflow of negatively charged Cl- ions.

With huge demand for still more optogenetic tools, Nagel and others now use gene editing techniques to create synthetic light-activated channels with new properties.
"Channelrhodopsins have low Ca2+ permeability, and Cl- channels like halorhodopsin can actually excite cells that have a high Cl- content. Despite a growing number of synthetic alternatives, highly-permeable light-sensitive channels that selectively allow Ca2+ into cells—or inhibit them by letting K+ out—remain high on many wish lists."

Engineering new control switches
To construct new light-activated tools for Na+/Ca2+ and K+ movement in and out of cells, the group took two existing ion channels activated by a universal cell messenger molecule called 'cAMP' and fused each with a bacterial enzyme that produces cAMP in response to light.
"We tried fusing the DNA segments in different ways, to find the configuration with the highest light-activated ion permeability," says senior study author and Nagel protégé Dr. Shiqiang Gao.
The results were a highly Ca2+-permeable channel, and a highly permeable K+-selective channel, each activated by blue light.
With collaborators Dr. Dennis Pauls from the University of Würzburg, Professor Robert Kittel and Dr. Nadine Ehmann from Leipzig University, the Nagel group set about testing these newly created channels in Drosophila (fruit fly) neurons and with Dr. Christine Gee and Ph.D. student Oana Constantin from the ZMNH Hamburg in rat neurons.
"These new channels when illuminated activated or inhibited isolated rat neurons, respectively" reports Dr. Gee, "and caused body contraction or relaxation when expressed in motor neurons in whole fruit fly larvae," adds Dr. Pauls.

Worthy additions to the optogenetic toolkit
The authors highlight the potential drawbacks of using cAMP to mediate light-responsiveness in these channels.
"cAMP itself is an important messenger in many cell processes, so controls expressing only the bacterial cAMP-producing enzyme are needed to discriminate between the effects of light-induced cAMP, Ca2+ and K+.
"Furthermore, cAMP produced by other enzymes native to the cell could directly activate the channels. This likely explains why the fruit fly larvae engineered to express the new channels are smaller, move slightly slower, and fail to mature into adult flies.
Gao and Nagel are nonetheless confident that their latest contributions are a valuable addition to the optogenetic toolkit, worthy of further characterization and development.
"In summary, we have generated new and efficient tools for optogenetic manipulation of Ca2+ or K+ permeability, which open new possibilities for probing the function of complex neuronal systems. These could be applied in adult flies—and perhaps eventually, mammals—by developing mutant channels with lower cAMP sensitivity, better localization to sites in neurons that send and receive electrical signals, and inducible expression—with genes switched on by temperature changes, for example."

More information: Sebastian Beck et al, Synthetic Light-Activated Ion Channels for Optogenetic Activation and Inhibition, Frontiers in Neuroscience (2018). DOI: 10.3389/fnins.2018.00643


Administrator has disabled public posting
Robert
useravatar
User Info

Re: Mainstream Watch

I came across this book "Live Paleo Style" by Miki Ben-Dor
http://www.paleostyle.com/?p=2236

In it he describes the importance of autonomy and the prime directive no coercion inclusive of children, as well as numerous other topics aligned with NH views.


Summary

Not long ago, humans were hunter-gatherers wandering in a natural environment. Now, we live in a completely different modern world with a set of genes that evolved during the preceding two and a half million years. The premise of this book is that humans will function optimally under conditions in which their genetic inventory has evolved over millions of years. On the other hand, they will suffer from adjustment problems if forced to live in different conditions. If we understand and become aware of the implications of this mismatch, the way to reduce suffering is paved before us.

Here are the main characteristics of the primal humans in their natural life and in their modern counterparts:

Living in a small and stable group – the primal human lived in groups of 15-50 who have known each other since birth. The level of interpersonal trust was maximal. In fact, a person rarely encountered people he did not know and whose interests differed from his own. Today we live in huge frameworks such as cities, states, and the globe, and in many cases depend on the decisions of people who do not know us and whom we do not know.

Most of the time was spent together – Even sleep was a group activity, and there was a lot of mutual care for the children. Presently, many of us live away from traditional support systems.

Sharing – Sharing food was one of the primary norms in hunter-gatherer groups. Sharing meant that none of the group members were hungry when other members were satiated. Usually, the hunter did not participate in the division of the hunt to avoid the appearance of their relatives’ preferences. Thus, no group member has ever seen another member abandoned to a state of hunger. Today personal ownership of property is sacred and homeless people do not get a second look.

Equality – There were no crowned leaders, and good hunters did not receive preferential treatment. Today inequality is the main engine behind the capitalist system and is accepted as natural.

Autonomy – No person could tell the other what to do, and no one owned the other’s time. Even parents tended not to tell their children what to do. Everything was done voluntarily and out of a sense of belonging and commitment to the group. Today we operate in a series of hierarchical structures, in the family, at work, and in the state, where we constantly fulfill privileged people’s demands.

No work – There was no commitment to work at certain hours and places. No repetitive tasks were performed for hours, and the final product of each task was visible and consumed or used immediately. Today we sell our time to produce a product that we usually do not see completed.

The tasks were short-term and easy to achieve – there was no long-term planning. There was no need for perseverance in performing a task over time. Today, many tasks require long-term persistence.

Lots of free time – Obtaining food only took a few hours, and plenty of time was left in the day to spend with the group. Today’s workday, including the commute, requires most daylight hours and often even some evening hours.

Nomadism – Nomadism was a form of diversity, and nomadism made it possible to switch groups to solve interpersonal tension. Today we are economically invested in one place, so even if the immediate environment is stressful or unpleasant, it is difficult to change.

Natural environment – The natural environment had no noise or pollution.

The risks were known and given – the simple lifestyle meant that the dangers were known, and so were the ways to reduce them. Today, rapid technological progress causes us to expect to be able to eliminate every risk. Facing uncertainty is a source of frustration and stress.

Authenticity – In the absence of work and in a state of perfect acquaintance with the group, there is no need to present a persona that is not authentic. Today we must show different personas in various social circumstances. Continuous emotional stress results from the mismatch between our situation now and during most of our evolution.


What can we do to help reduce some of that stress? Here are some suggestions, some easier and some more difficult to implement:

Recognize and get to know your hunter-gatherer’s core. Recognizing the source of anxiety and stress in the mismatch between our innate core and modern reality is the basic condition for relief. In most cases, you will be able to find your own ways to relieve anxiety and stress if you recognize their source.

Cultivate a small, stable community – Sometimes, family and close friends feel a little ‘boring.’ Try to overcome that feeling. Privacy is overrated. Share your life with others. There is a lot of value in steady, trusted, intimate companions.

Cultivate equality and autonomy – True for marriage or any other close relationship. People close to you stay close if they feel equal and free to develop their potential. In fact, you will feel better among equals.

Walk, ride, and travel in natural environments – Moving in natural environments was as basic as breathing to hunter-gatherers.

Find activities with immediate results – Learn a language, help other people.

Be spontaneous, just for the sake of it. Spontaneity is an expression of autonomy and is often associated with activities that bring immediate results.

Step away from large, hierarchical systems – Working in certain large organizations, such as the government and the army, is not for everyone.

Accept fate and uncertainty – In many cases, stress is caused by circumstances that can’t be changed.

Don’t feel ashamed when you crave free time.

Be authentic. Don’t be afraid to expose vulnerability. Authenticity is attractive.

Eat evolutionary-matched foods.

This book suggests early retirement and other behavioral and conceptual changes to overcome the emotional and physical mismatch. Some lucky people genuinely love their work, and some unlucky ones are economically unable to retire. Most of the measures that are recommended in the book can be taken without the need to retire.


Administrator has disabled public posting

Board Info

User Info:   Newest User :  sailing 1   Members Online: 0   Guests Online: 1125
Topic
Nouveau/nouvelle
Locked
Topic
Nouveau/nouvelle
Locked
Sticky
Active
New/Active
Sticky
Active
New/Active
New/Closed
New Sticky
Closed/Active
New/Locked
New Sticky
Locked/Active
Active/Sticky
Sticky/Locked
Sticky Active Locked
Active/Sticky
Sticky/Locked
Sticky/Active/Locked