I gotta split! Image of the Week - June 22, 2015
CIL:41466 - http://www.cellimagelibrary.org/images/41466
Description: Confocal image of a mitotic spindle in a dividing cell. The spindle is shown in yellow and the surrounding actin cytoskeleton is in blue. Sixth Prize, 2007 Olympus BioScapes Digital Imaging Competition.
Authors: Patricia Wadsworth and the 2007 Olympus Bioscapes Digital Imaging Competition®.
Licensing: Attribution Non-Commercial No Derivatives: This image is licensed under a Creative Commons Attribution, Non-Commercial, No Derivatives License
The Portuguese man o’ war delivers a powerful sting to its prey—and sometimes to people—through venom-filled structures on its tentacles. It is not a jellyfish, but rather a colony of different types of zooids (small animals). Jean Louis Coutant engraved the plate for this illustration.
These are rainbow eucalyptus trees (Eucalyptus deglupta) and hail from the Philippine Islands.
The trees get their name from the striking colours observed on their trunks and limbs. Although it may look like someone took a paintbrush to them, these colours are entirely natural. Unlike most trees, the rainbow eucalyptus does not have a thick, cork-like layer of bark on its trunk. The bark is smooth and as it grows it ‘exfoliates’ layers of spent tissue. This exfoliation technique occurs at different stages and in different zones of the tree.
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(Image caption: An fMRI scan shows regions of the brain that become active when devoutly religious study participants have a spiritual experience, including a reward center in the brain, the nucleus accumbens. Credit: Jeffrey Anderson)
This is your brain on God
Religious and spiritual experiences activate the brain reward circuits in much the same way as love, sex, gambling, drugs and music, report researchers at the University of Utah School of Medicine. The findings were published in the journal Social Neuroscience.
“We’re just beginning to understand how the brain participates in experiences that believers interpret as spiritual, divine or transcendent,” says senior author and neuroradiologist Jeff Anderson. “In the last few years, brain imaging technologies have matured in ways that are letting us approach questions that have been around for millennia.”
Specifically, the investigators set out to determine which brain networks are involved in representing spiritual feelings in one group, devout Mormons, by creating an environment that triggered participants to “feel the Spirit.” Identifying this feeling of peace and closeness with God in oneself and others is a critically important part of Mormons’ lives — they make decisions based on these feelings; treat them as confirmation of doctrinal principles; and view them as a primary means of communication with the divine.
During fMRI scans, 19 young-adult church members — including seven females and 12 males — performed four tasks in response to content meant to evoke spiritual feelings. The hour-long exam included six minutes of rest; six minutes of audiovisual control (a video detailing their church’s membership statistics); eight minutes of quotations by Mormon and world religious leaders; eight minutes of reading familiar passages from the Book of Mormon; 12 minutes of audiovisual stimuli (church-produced video of family and Biblical scenes, and other religiously evocative content); and another eight minutes of quotations.
During the initial quotations portion of the exam, participants — each a former full-time missionary — were shown a series of quotes, each followed by the question “Are you feeling the spirit?” Participants responded with answers ranging from “not feeling” to “very strongly feeling.”
Researchers collected detailed assessments of the feelings of participants, who, almost universally, reported experiencing the kinds of feelings typical of an intense worship service. They described feelings of peace and physical sensations of warmth. Many were in tears by the end of the scan. In one experiment, participants pushed a button when they felt a peak spiritual feeling while watching church-produced stimuli.
“When our study participants were instructed to think about a savior, about being with their families for eternity, about their heavenly rewards, their brains and bodies physically responded,” says lead author Michael Ferguson, who carried out the study as a bioengineering graduate student at the University of Utah.
Based on fMRI scans, the researchers found that powerful spiritual feelings were reproducibly associated with activation in the nucleus accumbens, a critical brain region for processing reward. Peak activity occurred about 1-3 seconds before participants pushed the button and was replicated in each of the four tasks. As participants were experiencing peak feelings, their hearts beat faster and their breathing deepened.
In addition to the brain’s reward circuits, the researchers found that spiritual feelings were associated with the medial prefrontal cortex, which is a complex brain region that is activated by tasks involving valuation, judgment and moral reasoning. Spiritual feelings also activated brain regions associated with focused attention.
“Religious experience is perhaps the most influential part of how people make decisions that affect all of us, for good and for ill. Understanding what happens in the brain to contribute to those decisions is really important,” says Anderson, noting that we don’t yet know if believers of other religions would respond the same way. Work by others suggests that the brain responds quite differently to meditative and contemplative practices characteristic of some eastern religions, but so far little is known about the neuroscience of western spiritual practices.
The study is the first initiative of the Religious Brain Project, launched by a group of University of Utah researchers in 2014, which aims to understand how the brain operates in people with deep spiritual and religious beliefs.
It is imperfection - not perfection - that is the end result of the program written into that formidably complex engine that is the human brain, and of the influences exerted upon us by the environment and whoever takes care of us during the long years of physical, psychological and intellectual development.
Rita Levi-Montalcini
Image Credit: Hammersmith Hospital in London
(via neuromorphogenesis)
Parkinson’s patients who take the drug levodopa, or L-Dopa, are inevitably disappointed. At first, during a “honeymoon” period, their symptoms (which include tremors and balance problems) are brought under control. But over time the drug becomes less effective. They may also need ultrahigh doses, and some start spending hours a day in a state of near-frozen paralysis.
A biotech company called Voyager Therapeutics now thinks it can extend the effects of L-Dopa by using a surprising approach: gene therapy. The company, based in Cambridge, Massachusetts, is testing the idea in Parkinson’s patients who’ve agreed to undergo brain surgery and an injection of new DNA.
Parkinson’s occurs when dopamine-making neurons in the brain start dying, causing movement symptoms that afflicted boxing champ Muhammad Ali and actor Michael J. Fox, whose charitable foundation has helped pay for the development of Voyager’s experimental treatment.
The cause of Parkinson’s isn’t well understood, but the reason the drug wears off is. It’s because the brain also starts losing an enzyme known as aromatic L-amino acid decarboxylase, or AADC, that is needed to convert L-Dopa into dopamine.
Voyager’s strategy, which it has begun trying on patients in a small study, is to inject viruses carrying the gene for AADC into the brain, an approach it thinks can “turn back the clock” so that L-Dopa starts working again in advanced Parkinson’s patients as it did in their honeymoon periods.
Videos of patients before and after taking L-Dopa make it obvious why they’d want the drug to work at a lower dose. In the ‘off’ state, people move in slow motion. Touching one’s nose takes an effort. In an ‘on’ state, when the drug is working, they’re shaky, but not nearly so severely disabled.
“They do well at first but then respond very erratically to L-Dopa,” says Krystof Bankiewicz, the University of California scientist who came up with the gene-therapy plan and is a cofounder of Voyager. “This trial is to restore the enzyme and allow them to be awakened, or ‘on,’ for a longer period of time.”
Voyager was formed in 2013 and later went public, raising about $86 million. The company is part of a wave of biotechs that have been able to raise money for gene therapy, a technology that is starting to pay off: after three decades of research, a few products are reaching the market.
Unlike conventional drug studies, those involving gene therapy often come with very high expectations that the treatment will work. That’s because it corrects DNA errors for which the exact biological consequences are known. Genzyme, a unit of the European drug manufacturer Sanofi, paid Voyager $65 million and promised hundreds of millions more in order to sell any treatments it develops in Europe and Asia.
“We’re working with 60 years of dopamine pharmacology,” says Steven Paul, Voyager’s CEO, and formerly an executive at the drug giant Eli Lilly. “If we can get the gene to the right tissue at the right time, it would be surprising if it didn’t work.”
But those are big ifs. In fact, the concept for the Parkinson’s gene therapy dates to 1986, when Bankiewicz first determined that too little AADC was the reason L-Dopa stops working. He thought gene therapy might be a way to fix that, but it wasn’t until 20 years later that he was able to test the idea in 10 patients, in a study run by UCSF.
In that trial, Bankiewicz says, the gene delivery wasn’t as successful as anticipated. Not enough brain cells were updated with the new genetic information, which is shuttled into them by viruses injected into the brain. Patients seemed to improve, but not by much.
Even though the treatment didn’t work as planned, that early study highlighted one edge Voyager’s approach has over others. It is possible to tag AADC with a marker chemical, so doctors can actually see it working inside patients’ brains. In fact, ongoing production of the dopamine-making enzyme is still visible in the brains of the UCSF patients several years later.
It is possible to tag AADC with a marker chemical, so doctors can actually see it working inside patients’ brains. Image Source: MIT Technology Review.
In some past studies of gene therapy, by contrast, doctors had to wait until patients died to find out whether the treatment had been delivered correctly. “This is a one-and-done treatment,” says Paul. “And anatomically, it tells us if we got it in the right place.”
A new trial under way, this one being carried out by Voyager, is designed to get much higher levels of DNA into patients’ brains in hopes of achieving better results. To do that, Bankiewicz developed a system to inject the gene-laden viral particles through pressurized tubes while a patient lies inside an MRI scanner. That way, the surgeon can see the putamen, the brain region where the DNA is meant to end up, and make sure it’s covered by the treatment.
There are other gene therapies for Parkinson’s disease planned or in testing. A trial developed at the National Institutes of Health seeks to add a growth factor and regenerate cells. A European company, Oxford BioMedica, is trying to replace dopamine.
Altogether, as of this year, there were 48 clinical trials under way of gene or cell replacement in the brain and nervous system, according to the Alliance for Regenerative Medicine, a trade group. The nervous system is the fourth most common target for this style of experimental treatment, after cancer, heart disease, and infections.
Voyager’s staff is enthusiastic about a study participant they call “patient number 6,” whom they’ve been tracking for several months—ever since he got the treatment. Before the gene therapy, he was on a high dose of L-Dopa but still spent six hours a day in an “off” state. Now he’s off only two hours a day and takes less of the drug.
That patient got the highest dose of DNA yet, covering the largest brain area. That is part of what makes Voyager think higher doses should prove effective. “I believe that previous failure of gene-therapy trials in Parkinson’s was due to suboptimal delivery,” says Bankiewicz.
Image Credit: L.A. JOHNSON
Source: MIT Technology Review (by Antonio Regalado)
With the help of two young patients with a unique neurological disorder, an initial study by scientists at the National Institutes of Health suggests that a gene called PIEZO2 controls specific aspects of human touch and proprioception, a “sixth sense” describing awareness of one’s body in space. Mutations in the gene caused the two to have movement and balance problems and the loss of some forms of touch. Despite their difficulties, they both appeared to cope with these challenges by relying heavily on vision and other senses.
“Our study highlights the critical importance of PIEZO2 and the senses it controls in our daily lives,” said Carsten G. Bönnemann, M.D., senior investigator at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and a co-leader of the study published in the New England Journal of Medicine. “The results establish that PIEZO2 is a touch and proprioception gene in humans. Understanding its role in these senses may provide clues to a variety of neurological disorders.”
Dr. Bönnemann’s team uses cutting edge genetic techniques to help diagnose children around the world who have disorders that are difficult to characterize. The two patients in this study are unrelated, one nine and the other 19 years old. They have difficulties walking; hip, finger and foot deformities; and abnormally curved spines diagnosed as progressive scoliosis.
Working with the laboratory of Alexander T. Chesler, Ph.D., investigator at NIH’s National Center for Complementary and Integrative Health (NCCIH), the researchers discovered that the patients have mutations in the PIEZO2 gene that appear to block the normal production or activity of Piezo2 proteins in their cells. Piezo2 is what scientists call a mechanosensitive protein because it generates electrical nerve signals in response to changes in cell shape, such as when skin cells and neurons of the hand are pressed against a table. Studies in mice suggest that Piezo2 is found in the neurons that control touch and proprioception.
“As someone who studies Piezo2 in mice, working with these patients was humbling,” said Dr. Chesler. “Our results suggest they are touch-blind. The patient’s version of Piezo2 may not work, so their neurons cannot detect touch or limb movements.”
Further examinations at the NIH Clinical Center suggested the young patients lack body awareness. Blindfolding them made walking extremely difficult, causing them to stagger and stumble from side to side while assistants prevented them from falling. When the researchers compared the two patients with unaffected volunteers, they found that blindfolding the young patients made it harder for them to reliably reach for an object in front of their faces than it was for the volunteers. Without looking, the patients could not guess the direction their joints were being moved as well as the control subjects could.
The patients were also less sensitive to certain forms of touch. They could not feel vibrations from a buzzing tuning fork as well as the control subjects could. Nor could they tell the difference between one or two small ends of a caliper pressed firmly against their palms. Brain scans of one patient showed no response when the palm of her hand was brushed.
Nevertheless, the patients could feel other forms of touch. Stroking or brushing hairy skin is normally perceived as pleasant. Although they both felt the brushing of hairy skin, one claimed it felt prickly instead of the pleasant sensation reported by unaffected volunteers. Brain scans showed different activity patterns in response to brushing between unaffected volunteers and the patient who felt prickliness.
Despite these differences, the patients’ nervous systems appeared to be developing normally. They were able to feel pain, itch, and temperature normally; the nerves in their limbs conducted electricity rapidly; and their brains and cognitive abilities were similar to the control subjects of their age.
“What’s remarkable about these patients is how much their nervous systems compensate for their lack of touch and body awareness,” said Dr. Bönnemann. “It suggests the nervous system may have several alternate pathways that we can tap into when designing new therapies.”
Previous studies found that mutations in PIEZO2 may have various effects on the Piezo2 protein that may result in genetic musculoskeletal disorders, including distal arthrogryposis type 5, Gordon Syndrome, and Marden-Walker Syndrome. Drs. Bönnemann and Chesler concluded that the scoliosis and joint problems of the patients in this study suggest that Piezo2 is either directly required for the normal growth and alignment of the skeletal system or that touch and proprioception indirectly guide skeletal development.
“Our study demonstrates that bench and bedside research are connected by a two-way street,” said Dr. Chesler. “Results from basic laboratory research guided our examination of the children. Now we can take that knowledge back to the lab and use it to design future experiments investigating the role of PIEZO2 in nervous system and musculoskeletal development.”
R.I.P. Vera Rubin; 1928-2016.
She never did win the Nobel prize for her discovery.
Midwives and nurses sometimes came under suspicion because of their specialised knowledge and success - or failure - in treating those who were sick. These healing roles were traditionally taken on by women who, until around the turn of the nineteenth century, were excluded from formal medical training. However, many still practiced medicine in their homes and villages, and what they had learned came from shared knowledge and trial and error, rather than accepted official sources. A medical education might not have been a great help in any case. In the days before germ theory the causes of sickness and the reasons for recovery were not obvious. Any recoveries could be seen as miraculous … or the result of witchcraft.
Treating sickness and disease pre-germ theory was largely guesswork. All sorts of noxious compounds were administered to ailing individuals, and if they produced any effect on the body, be it vomiting, diarrhoea or sweating, it was seen as a good thing – and that was the practice of the so-called professionals. It is not hard to see how images of unofficial healers and herbalists (both men and women) stooping over boiling pots of herbs, roots and who-knows-what, could become a template for the image of a witch, especially when many of the concoctions they produced had such unpleasant effects on their patients.
Having said that, herbalists and traditional healers should not be dismissed as completely ignorant of the medical benefits of some of the plants and poultices they used. Some of the ingredients associated with traditional healing and witches’ potions have been found to be hugely beneficial to medicine once they have been isolated, tested and modified. Science has enabled us to identify the key components of some plants and test them to determine how and when they should be administered safely and effectively. Chemists have modified the structures of some of the compounds to reduce side-effects, make drugs more potent or lower their toxicity.
New Approach to Treating Alzheimer’s Disease
Alzheimer’s disease (AD) is one of the most common form of dementia. In search for new drugs for AD, the research team, led by Professor Mi Hee Lim of Natural Science at UNIST has developed a metal-based substance that works like a pair of genetic scissors to cut out amyloid-β (Aβ), the hallmark protein of AD.
The study has been featured on the cover of the January 2017 issue of the Journal of the American Chemical Society (JACS) and has been also selected as a JACS Spotlight article.
Alzheimer’s disease is the sixth leading cause of death among in older adults. The exact causes of Alzheimer’s disease are still unknown, but several factors are presumed to be causative agents. Among these, the aggregation of amyloid-β peptide (Aβ) has been implicated as a contributor to the formation of neuritic plaques, which are pathological hallmarks of Alzheimer’s disease (AD).
As therapeutics for AD, Professor Lim suggested a strategy that uses metal-based complexes for reducing the toxicity of the amyloid beta (Aβ). Althought various metal complexes have been suggested as therapeutics for AD, none of them work effectively in vivo.
The research team has found that they can hydrolyze amyloid-beta proteins using a crystal structure, called tetra-N methylated cyclam (TMC). Hydrolysis is the process that uses water molecules to split other molecules apart. The metal-mediated TMC structure uses the external water and cut off the binding of amyloid-beta protein effectively.
In this study, the following four metals (cobalt, nickel, copper and zinc) were placed at the center of the TMC structure. When the double-layered cobalt was added to the center, the hydrolysis activity was at the highest.
The research team reported that the cobalt-based metal complex (Co(II)(TMC)) had the potential to penetrate the blood brain barrier and the hydrolysis activity for nonamyloid protein was low. Moreover, the effects of this substance on the toxicity of amyloid-beta protein were also observed in living cell experiments.
“This material has a high therapeutic potential in the treatment of Alzheimer’s disease as it can penetrate the brain-vascular barrier and directly interact with the amyloid-beta protein in the brain,” says Professor Lim.
This study has also attracted attention by the editor of the Journal of the American Chemical Society. “Not only do they develop new materials, but they have been able to propose details of the working principles and experiments that support them,” according to the editor.
“As a scientist, this is such a great honor to know that our recent publication in JACS was highlighted in JACS Spotlights,” says Professor Lim. “This means that our research has not only been recognized as an important research, but also has caused a stir in academia.”
A pharmacist and a little science sideblog. "Knowledge belongs to humanity, and is the torch which illuminates the world." - Louis Pasteur
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