segunda-feira, 12 de outubro de 2015

10 Things You Never Knew About the Clitoris

 

 

October 5, 2015 | By Kristine Thomason

10 AmazingFactsAbouttheClitoris

Brace yourselves ladies, there’s a whole lot to know about the clitoris that they didn’t teach us in health class. While you’ve probably heard the many unfortunate nicknames for this body part (including “the bean”— who came up with that?), and you definitely know a thing or two about the ahem, functions, of the clitoris, you might not know that it actually gets erect, for example.

Yep, “lady boners” (another very unfortunate nickname, sorry) are real.

To help you become a bit more “cliterate,” here are 10 facts about this amazing part of your anatomy.

It’s truly unique

When it comes to climaxing, “the clitoris is really, really crucial,” says Jim Pfaus, PhD, professor and sex researcher at Concordia University in Montreal. But that’s not the only thing that makes it special: the clitoris is actually the only organ in the body with the sole function of providing pleasure.

It’s long been a mystery

Until 1998 most textbooks only illustrated the external glans. That’s when Helen O’Connell, an Australian urologist, revealed through a series of MRI studies that the clitoris is actually a complex, powerful organ system composed of a total of eighteen parts, two thirds of which are interior.

It’s much more than meets the eye

“When people talk about the clitoris, they’re usually just talking about the glans—the very sensitive outside part,” says Rebecca Chalker, PhD, Professor of Sexology at Pace University and author of The Clitoral Truth ($12, amazon.com). But the bump you can see on the vulva is only the tip of an iceberg.

The internal part is connected to the glans by the corpora cavernosa, two spongey areas of erectile tissue. Farther down, the corpora cavernosa branches off into a pair of wings known as the crura which extend into the body and around the vaginal canal like a wishbone. Then, underneath the crura are the clitoral vestibules, or vestibular bulbs. Like much of the clitoris, these sac-like structures of tissue become engorged with blood when you get aroused.

It’s got a lot of nerve

The clitoris is the most nerve-rich part of the vulva, says Debra Herbenick, PhD, a sexual health educator from The Kinsey Institute. The glans contains about 8,000 nerve endings, making it the powerhouse of pleasure. To get some perspective, that’s twice as many nerve endings as the penis. And its potential doesn’t end there. This tiny erogenous zone spreads the feeling to 15,000 other nerves in the pelvis, which explains why it feels like your whole body is being taken over by your O-M-G moment.

Every woman’s is different

Women are all unique, so why would clitorises be any different? Every woman needs a different kind of stimulation to feel satisfied, depending on her unique biology. “Just because it’s sensitive doesn’t mean everyone wants it to be stimulated directly,” Herbenick says. “Some women prefer touching near the clitoris but not on it.” Pfaus agrees: “If she’s too sensitive with direct stimulation, more of that may make her want to kill you.”

It’s the real G-spot

We’ve all heard about the infamous G-spot: Does it exist? Do all women have one? Yes and yes. That’s because the G-spot is actually the clitoris. This notorious pleasure zone became sensationalized back in the 80s which, as Chalker explains, “created this idea that if you could only access the G-spot inside the vagina, it would promote female orgasm.” But we’ve since learned that some women may feel more sensation via the internal shafts of the clitoral complex (hence why some women might like vaginal penetration more than others), while others prefer external touch. One way is not better than another way, Pfaus adds; it’s really about exploring the possibilities to find out what you like best.

It’s very similar to the penis…

“The clitoris and the penis are somewhat mirror images of each other, just organized differently,” Chalker explains. “In fact, up until two weeks of pregnancy, all embryos appear to be female.” It’s not until week eight of gestation that testosterone kicks in and the penis starts to form. “None of these parts disappear, they just get rearranged,” Chalker says. For example the internal part of the clitoris, also made of erectile tissue, becomes the frame of the penis. With this concept in mind, Chalker points out: “If you consider the clitoris only consisting of the glans, then that’s like saying the only part of a penis is the tip.”

…It even gets erect

“When we talk about erection, we can’t just talk about the penis,” Pfaus says. “We have to talk about the clitoris.” Sure, it might be less noticeable for women, but it can definitely be observed and felt. This occurs when the vestibular bulbs become engorged with blood during arousal. The blood is then trapped here until released via orgasmic spasms.

Size doesn’t matter

Like men, women can get self-conscious about their sexy parts. But guess what? Just like penises, clits come in all shapes and sizes. And size doesn’t matter for either, Chalker explains.  Think of it this way: since the brain is your main sex organ, the genitals are simply the receptors of pleasure. “It has to do with visual, tactile, and oral stimulation,” Chalker says, “rather that the actual size of the clit. So while glans may vary from woman to woman, this shouldn’t affect the pleasure-potential.” Also worth noting: chances are size doesn’t (or, at least,shouldn’t) matter to your partner.

It can grow with age

Although the size of your clitoris doesn’t impact your sex life, don’t be surprised if it changes dimensions over your lifetime. According to Chalker, due to a change in hormone levels after menopause, the clit may enlarge for many women. So if you notice some differences in the size of your lady parts over time, don’t be alarmed.

http://news.health.com/2015/10/05/10-things-you-never-knew-about-the-clitoris/

NASA reveals roadmap to Mars

 

 

Mars has released a document outlining its steps to Mars

Mars has released a document outlining its steps to Mars (Credit: NASA/JPL-Caltech/MSSS)

That NASA has aspirations for a manned mission to the Red Planet is already well known, but the space agency has now revealed in greater detail how it plans to make such a mission reality. In a document titled "NASA's Journey to Mars: Pioneering Next Steps in Space Exploration," the expedition is broken down into three separate phases, painting a picture of the incremental scientific advances needed to land humans on the Martian surface.

"NASA’s strategy connects near-term activities and capability development to the journey to Mars and a future with a sustainable human presence in deep space," says William Gerstenmaier, associate administrator for Human Exploration and Operations at NASA Headquarters.

The first of NASA's steps to Mars falls under the title "Earth Reliant," and centers on research to be carried out on the International Space Station (ISS). In this microgravity test-bed, the agency will continue developing technologies aimed at improving human health to prepare for manned missions to deep space.

In the second stage, NASA will carry out manned missions in cislunar-space, that is the area between the Earth and the Moon or the Moon's orbit. Dubbed "Proving Ground," this phase will entail developing and validating capabilities required to allow humans to live in environments further away from our home planet, such as on a certain dusty, red planet.

The third and final stage, called "Earth Independence," is intended to capitalize on the advances in the previous steps to bring humans to the Mars vicinity, first to low-Mars orbit and possibly one of the planet's moons, and then to touch down on the surface.

Together, the phases are intended to address three hurdles NASA sees as fundamental in getting to Mars: transportation (the ability for humans and cargo to safely travel into deep space), working in space (so crew members and robots can be productive once they get there) and staying healthy (for survival). The agency will discuss the plan with congress and partners in the coming weeks.

The entire Journey to Mars: Pioneering Next Steps in Space Exploration document can be read online here.

Source: NASA

 

http://www.gizmag.com/nasa-journey-to-mars-plans/39804/

Chile is creating the largest protected marine park in the Americas

 

 

The largest marine park in the Americas will soon protect the waters aroundChile. Announced by President Michelle Bachelet of Chile, the forthcoming Nazca-Desventuradas Marine Park will encompass a whopping 114,872 square miles of ocean. Applauded by non-profit Oceana, the new marine park will protect 12 percent of Chile’s marine surface area from environmental destruction.

green design, eco design, sustainable design, National Geographic, Nazca-Desventuradas Marine Park, Oceana, ocean health, ocean conservation

Chile is known as one of the world’s largest fishing countries, making the creation of the Nazca-Desventuradas Marine Park a monumental turning point in global ocean conservation. The Desventuradas is known as one of the world’s most pristine and diverse marine environments, explored and documented extensively in 2013 by researchers, scientists and photographers from Oceanaand National Geographic. The expedition revealed gorgeous imagery of the regions’ marine life, vast oceanic terrains, and lurid underwater plant life.

Related: New Zealand is about to create one of the world’s largest marine reserves

Rich kelp forests, underwater mountains, booming fish populations, beautiful coral reefs and deep sea sharks were captured on camera by National Geographic photographers, illustrating the need to protect this area from fishing and further development. Aside from conservation, the marine park proposal will also help to rebuild depleted fisheries and lobster populations in the Juan Fernandez community.

The creation of the Nazca-Desventuradas Marine Park will help to preserve the rich biodiversity of South America, acting as a conservation and research center for the scientific communities of the world. By protecting this region from overfishing and pollution, the marine park will help to make steps against the effects of climate change and mass species extinction.

+ National Geographic

+ Oceana

 

http://inhabitat.com/chile-to-sanction-largest-protected-marine-park-in-the-americas

This May Be the Youngest Cowgirl Ever

 

 

150828-youngest-cowgirl-05

Jean Anne Evans began riding horses when she was one month old

Living in the YouTube era, it’s never entirely surprising to see a 5-year-old piano prodigy or a breakdancing toddler go viral—impressive as their talents may be. Half a century ago, those baby Einsteins got their 15 minutes of fame in a more old-fashioned medium: the back pages of LIFE magazine.

Fifteen-month-old Jean Anne Evans was one such child. The Texan toddler was born into a family of ranchers and horseback riders, and first straddled a saddle (with her mother in tow) at the tender age of one month. When LIFE photographer Alan Grant visited her family’s farm near Fort Davis, he found her holding her own atop her 25-year-old horse, Toy Boy.

Despite her prowess, LIFE wrote, she occasionally “betrays her years by dropping off to sleep suddenly in mid-roundup.” Thankfully, her mother’s saddle made for just the place to take a nap.

Liz Ronk, who edited this gallery, is the Photo Editor for LIFE.com. Follow her on Twitter @lizabethronk.

http://time.com/4015064/youngest-cowgirl-photos/

7 Health Benefits of Sweet Potatoes

 

485214825.jpg - Phoebe_Lapine / Getty Images

Phoebe_Lapine / Getty Images

1. High in beta-Carotene: A type of vitamin A, beta-Carotene helps keep your eyes and skin healthy. Beta-Carotene also plays a vital role in the immune system and keeps the body protected from foreign agents. Scientists think the beta-Carotene can also help mediate the damage caused by Alzheimer's Disease and Parkinson's Disease.

2. High in Vitamin B3: Also called Niacin, vitamin B3 helps convert sugars, fats, and proteins into calories for the body to use.

It's also important in the repair of DNA in the body and helps reduce heart disease.

3. Tons of Vitamin D. Your body actually produces vitamin D as a reaction to sunlight. Vitamin D plays an important role in your mood and can help with the production of dopamine and works to keep up the body's energy levels.

A lack of sunlight can lead a lack of vitamin D, which in turn can lead to Seasonal Affective Disorder - a sort of depression linked to the seasons, particularly winter when there is less sunlight. Eating sweet potatoes, a food packed with vitamin D, can help keep your energy up and elevate your mood. 

4. Antifungal and Antiviral Properties: Sugar compounds called glycosides found in sweet potatoes are particularly unique. They've been shown to have the potential to hunt down and snuff out foreign fungal and viral agents in the body and eliminate them. This means they can assist in preventing diseases caused by harmful biological agents in the body.

5. An Excellent Source of Magnesium: An important part in numerous functions of the body magnesium is mandatory for bone health, reducing blood pressure, and for ensuring proper functions of the endocrine system (i.e., it helps you pee and assists in processing booze).

Magnesium also *ahem* keeps you regular. Sweet potatoes have shockingly high levels of magnesium and are often a prescribed food for patients with heart and circulatory problems as well as endocrine problems.

6. Iron? Sweet potatoes have plenty! It sounds odd to say we need iron - a metal - in our body, but iron is a unique metal in that it has great bonding capacity.

Due to this, iron is able to transport oxygen to cells and acts as a critical part of muscle strength and movement. Iron is also a critical piece of the numerous proteins and enzymes that our bodies produce for everyday functions. Sweet potatoes are packed with iron and offer a delicious way to keep strong.

7. Anti-inflammatories Galore: The sweet potato has the epic ability to repress and reduce the amount of certain inflammatory compounds that develop in the body when it is damaged. The means the sweet potato actively works to reduce inflammation of muscle cells and, in particular, nerve cells. Reduced inflammation around nerve cells means nerves are able to fire electrical signals more efficiently and reduce the pain of diseases like multiple sclerosis.

http://produce.about.com/od/Root-Vegetables/fl/7-Health-Benefits-of-Sweet-Potatoes.htm

domingo, 11 de outubro de 2015

How Your Cat Could Make You Mentally Ill

 

 

New research examines the link between cat-carried parasite and schizophrenia

Cats may rule the Internet and make beloved pets, but a recent study has revealed that they may also be linked to mental illness.

As cute as they can be, cats can carry a parasite called Toxoplasma gondii (T. gondii), which can be passed on to humans. The Centers for Disease Control and Prevention (CDC) estimates more than 60 million people in the U.S. may have it,CBS reports. Though most people will never develop symptoms of a T. gondii infection, those with weakened immune symptoms could develop an illness called toxoplasmosis, which could lead to miscarriages, fetal development disorders, a flu-like illness, blindness and in extreme cases even death. Recently published research now suggests that there could be a link between the cat-carried parasite and mental illness.

The researchers, E. Fuller Torrey of the Stanley Medical Research Institute and Dr. Robert H. Yolken of Stanley Laboratory of Developmental Neurovirology at the Johns Hopkins University School of Medicine, have been investigating a possible link between the parasite and mental illnesses such as schizophrenia and bipolar disorder. The new research, published in Schizophrenia Research, examines whether cat ownership in childhood is significantly more common in families in which the child later becomes seriously mentally ill.

“Cat ownership in childhood has now been reported in three studies to be significantly more common in families in which the child is later diagnosed with schizophrenia or another serious mental illness,” the authors of the study said in a statement.

Another recent study, published in the journal Acta Psychiatrica Scandinavica, looked at dozens of published studies that also found that T. gondii infection is associated with mental disorders. The results of the research showed that a person infected with the parasite was almost twice as likely to develop schizophrenia.

So what can cat-loving parents do? Study author Torrey told CBS that, “Children can be protected by keeping their cat exclusively indoors and always covering the sandbox when not in use.”

Black Cat Audition, 1961

<b>Caption from LIFE.</b> Who's afraid of all these black cats?

Black cats auditioning for a role in <i>The Black Cat,</i> a new version of the Edgar Allan Poe classic in 1961.

Black cats auditioning for a role in <i>The Black Cat,</i> a new version of the Edgar Allan Poe classic in 1961.

Black cats auditioning for a role in <i>The Black Cat,</i> a new version of the Edgar Allan Poe classic in 1961.

Ralph Crane—The LIFE Picture Collection/Getty Images

 

http://time.com/3912258/cats-parasite-mental-illness/

 

New approach to creating computer memory

 

 

Thu, 10/08/2015 - 7:41am

Chad Boutin, NIST

A magnetized cobalt disk (red) placed atop a thin cobalt-palladium film (light purple background) can be made to confer its own ringed configuration of magnetic moments (orange arrows) to the film below, creating a skyrmion in the film (purple arrows). The skyrmion, which is stable at room temperature, might be usable in computer memory systems. Image: Dustin Gilbert/NIST

A magnetized cobalt disk (red) placed atop a thin cobalt-palladium film (light purple background) can be made to confer its own ringed configuration of magnetic moments (orange arrows) to the film below, creating a skyrmion in the film (purple arrows). The skyrmion, which is stable at room temperature, might be usable in computer memory systems. Image: Dustin Gilbert/NISTWhat can skyrmions do for you? These ghostly quantum rings, heretofore glimpsed only under extreme laboratory conditions, just might be the basis for a new type of computer memory that never loses its grip on the data it stores.

Now, thanks to a research team including scientists from NIST, the exotic ring-shaped magnetic effects have been coaxed out of the physicist's deepfreeze with a straightforward method that creates magnetic skyrmions under ambient room conditions. The achievement brings skyrmions a step closer for use in real-world data storage as well as other novel magnetic and electronic technologies.

If you have a passing familiarity with particle physics, you might expect skyrmions to be particles; after all, they sound a lot like fermions, a class of particles that includes protons and neutrons. But skyrmions are not fundamental pieces of matter (not even of yogurt); they are effects named after the physicist who proposed them. Until just recently, magnetic skyrmions had only been seen at very low temperatures and under powerful magnetic fields.

The magnetic force in each individual atom in a magnet--what physicists call their "magnetic moments"—all line up the same way, like tiny compasses all pointing in the same direction. But under extreme conditions, certain magnetic materials (such as MnSi or FeCoSi) can, instead, develop spots where the moments curve and twist, forming a winding, ring-like configuration. These unusual objects possess an elasticity that protects them from outside influence, meaning the data they store would not be corrupted easily, even by stray magnetic fields or physical defects within the material. As a result, magnetic skyrmions present a promising basis for information memory systems and other nanoelectronic devices.

A hurdle in using traditional skyrmions was the extreme lab conditions needed to form them. Until recently, scientists glimpsed magnetic skyrmions only at low temperatures. While NIST's Dustin Gilbert was a graduate student in Kai Liu's lab at the Univ. of California, Davis, he and Liu not only designed an approach to make the quantum objects, but also their creations remained stable at room temperature, with no magnetic field.

It took a trip to NIST to confirm the skyrmions' existence. Creating them involves placing arrays of tiny magnetized cobalt disks atop a thin film made of cobalt and palladium; the NIST Center for Neutron Research (NCNR) had just developed a state-of-art polarized neutron reflectometer that was well suited to study their lab results. Working with NCNR scientists, the team used neutrons to see through the disk to spot the skyrmions underneath. The team also captured images of the whirling configurations in the disk array at NIST's Center for Nanoscale Science and Technology (CNST) and Lawrence Berkeley Laboratory.

According to Gilbert, the findings should interest anyone following spintronics, a field that aims to use magnetic effects such as those skyrmions exhibit for information storage and processing.

"The idea that has been discussed is that, for example, you could just push these stable magnetic bundles in single file down a line and read their data. The advantage here is that you'd need way less power to push them around than any other method proposed for spintronics," says Gilbert, who recently began a postdoctoral fellowship at the NCNR. "What we need to do next is figure out how to make them move around. But for now, we can start exploring how we might use skyrmions in technology—the playground is open."

Source: NIST

http://www.rdmag.com/news/2015/10/new-approach-creating-computer-memory

 

 

Agave: The Elixir for Parties and Biofuel?

 

 

Thu, 10/08/2015 - 10:03am

Greg Watry, Digital Reporter

Image: T photography/Shutterstock.com

Image: T photography/Shutterstock.com

Famous for its role in tequila and mezcal production, the agave plant was worshipped by Mexico’s natives long before the Spaniards arrived in the 15th century. The Aztec goddess Mayheul was closely associated with agave, a symbol for life, health, dance and fertility. According to the International Organic Agave Alliance, archeological findings date the plants usage back some 10,000 years.

But the broad-leafed, spiky plant may have more use than just supplying a bottle of spirits for a wild weekend revelry.

Researchers from the Australian Research Council Centre of Excellence in Plant Cell Walls released a study in PLOS ONE touting the plant as a potential source for biofuel.

“Bioethanol yields from agave fermentation could rival the most successful biofuel feedstock crops around the world,” said co-author Prof. Rachel Burton, of the Univ. of Adelaide’s School of Agriculture, Food and Wine. “Importantly, it doesn’t compete with food crops; it’s fast growing so the whole plant could be used rather than just harvesting the leaves; and it is up to 10 times more water efficient than some other crop plants.”

Studying Agave americana and Agave tequilana, the researchers found use of the former could yield 4,000 to 13,600 L/ha/yr, and the latter, 4,400 to 14,800 L/ha/yr. If the whole plant is used, that is. Even at the low end, the values surpass theoretical yields from first-generation feedstocks, such as corn, wheat and sugarcane, according to the researchers. The high values double yields from recently investigated biofuel sources, such as poplar, sorghum and switchgrass.

Tequila and mezcal are made from the stem tissue of Agave tequilana when the plants are between eight and 12 years old. When heated, the stem tissues release fermentable fructose. However, the leftover leaves, which the researchers say accounts for 66% of the biomass, is discarded.

“Waste leaves could generate up to (8,000 L/ha/yr) and increase profit from the agave crop, or, if directly separating and fermenting the juice was more economically viable, up to 4,000 (L/ha/yr) is achievable,” said Burton.

Research is in progress to find the best cultivation methods for bioethanol production.

 

http://www.rdmag.com/articles/2015/10/agave-elixir-parties-and-biofuel

sábado, 10 de outubro de 2015

Smoking set to kill one in three young men in China

 


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One in three of all the young men in China will eventually be killed by tobacco, unless a substantial proportion stop smoking, according to new research published in The Lancet.

Two-thirds of the young men in China start to smoke, mostly before age 20, and the study, led by researchers from Oxford University, UK, the Chinese Academy of Medical Sciences and the Chinese Centre for Disease Control, shows that around half of those who start smoking cigarettes as young men will eventually be killed by tobacco, unless they stop permanently.

The researchers conducted two large, nationally representative studies 15 years apart, tracking the health consequences of smoking in a large group of people in China. The first study took place in the 1990s, and involved a quarter of a million men. The second study is ongoing, and involved half a million men and women.

The results show that in China the annual number of tobacco deaths, mostly among men, had reached 1 million by 2010, and if current trends continue, it will be 2 million by 2030. Among Chinese women, however, smoking rates have plummeted and the risk of premature death from tobacco is low and falling.

In recent decades there has been a large increase in cigarette smoking by young men, and the research shows the consequences that are now emerging. The proportion of all male deaths at ages 40-79 that are attributed to smoking has doubled, from about 10% in the early 1990s, to about 20% now. In urban areas this proportion is higher, at 25%, and is still rising. In rural areas it is currently lower, but is set to rise even more steeply than in cities, due to the high prevalence of smoking and low rate of cessation in rural China.

Conversely, the women of working age in China now smoke much less than the older generation. About 10% of the women born in the 1930s smoked, but only about 1% of those born in the 1960s did so. Hence, overall female deaths caused by tobacco are decreasing, and less than 1% of deaths in women born since 1960 are due to tobacco. Other studies, however, have shown a recent increase in smoking uptake by young women that could eventually reverse this downward trend.

Professor Zhengming Chen from the University of Oxford, UK, a study co-author, says: "About two-thirds of young Chinese men become cigarette smokers, and most start before they are 20. Unless they stop, about half of them will eventually be killed by their habit."

However, an increasing proportion of smokers are choosing to stop, and the study results show that between 1991 and 2006, the proportion of smokers who had quit rose from 3% to 9%. For smokers who stopped before developing any serious disease, after ten years of not smoking their risk was similar to that of people who had never smoked.

According to study co-author Professor Liming Li, from the Academy of Medical Sciences, Beijing, China, "Without rapid, committed, and widespread action to reduce smoking levels China will face enormous numbers of premature deaths."

http://www.sciencedaily.com/releases/2015/10/151008191048.htm

sexta-feira, 9 de outubro de 2015

Lab has made new discoveries at the cellular, molecular levels about how the eye processes light

 

 

The image shows a Drosophila compound eye stained with antibodies that recognize TRP (magenta) and anti-XPORT-B (green).

Credit: Image courtesy of University of California - Santa Barbara

An animal's ability to perceive light incorporates many complex processes. Now, researchers in Craig Montell's lab at UC Santa Barbara have used fruit flies and mice to make novel discoveries about sensory physiology at both cellular and molecular levels that are important for light processing.

Their most recent findings, which improve the scientific understanding of the signaling cascade necessary for phototransduction -- the process by which light is converted into electrical signals in the photoreceptor cells in the retina of the eye -- appear today in the journal Cell Reports.

More than 25 years ago, Montell discovered TRP channels, which allow animals to detect light, chemicals in food, mechanical force and changes in temperature. These proteins act at the cell surface, but very little was known about the mechanism by which they are transported to the cell surface.

Until now, scientists knew of only one protein, XPORT, that was a "helper protein" involved in getting TRP proteins to the outer surface of cells. However, using the fruit fly (Drosophila melanogaster), postdoctoral fellow Zijing Chen found that the XPORT gene in fact encodes two unrelated molecular chaperone proteins -- XPORT-A and XPORT-B -- and both are critical for moving TRP channels out of their synthesis site inside the cells.

"This discovery is important because if TRP proteins don't get to the cell surface, they are not going to be able to function, and the animals will not see properly," said Montell, a professor in UCSB's Department of Molecular, Cellular, and Developmental Biology.

"The light that activates the photoreceptor cells is not directly activating TRP but rather a light sensor called rhodopsin," Montell explained. This primary pigment found in photoreceptor cells is extremely sensitive to light. "What's interesting is that both XPORT-A and XPORT-B are required for getting rhodopsin and TRP to the cell surface," he added.

According to Montell, mutations in TRP have been linked to neurodegenerative disorders, pain syndromes, neuropathies and bone deformations. Understanding the intricacies of TRP function is the first step toward identifying drugs that could affect their activity and one day be used as therapeutic targets.

TRP channels also function in light sensation in mammals, including humans. However, they do not have central roles in rods or cones, which allow mammals to see images. Rather, TRPs in mammals function in a third class of photoreceptor cell, intrinsically photosensitive retinal ganglion cells (ipRGCs). The ipRGCs are necessary for setting circadian rhythms by light as well as pupillary constriction in response to light. The ipRGCs are activated by bright light and also stimulated through pathways initiated in rods and cones. However, the pathways and molecules that allow rods and cones to stimulate ipRGCs indirectly by light have been poorly understood.

In another paper, published in the journal Molecular Biology of the Cell, Marquis Walker, a postdoctoral fellow working with Montell, used mice to explore the indirect pathway for activating ipRGCs. They found that a protein called retinal degeneration B2 (RDGB2) was critical in connector neurons called amacrine cells located in the inner retina, between the rods and cones and ipRGCs.

"This study reveals the first molecular player that is important in sending signals from the rods into the ipRGCs," Montell said. "This indirect communication allows the ipRGCs to respond to dim light that activates rod photoreceptor cells."

The first RDGB protein was identified in the eye of the fruit fly and Montell and Walker wanted to determine its role in the mammalian retina. They found that RDGB2 in mice is required for normal circadian activity and pupil constriction -- but only in dim light.

"Understanding all the cells, pathways and molecules is necessary if you want to develop therapies for jet lag or problems related to circadian rhythm," Montell said. "We need to understand the whole cellular and molecular mechanism in order to ultimately come up with new approaches and drugs to deal with these issues."


Story Source:

The above post is reprinted from materials provided by University of California - Santa Barbara. The original item was written by Julie Cohen. Note: Materials may be edited for content and length.


Journal Reference:

  1. zijing Chen, Hsiang-Chin Chen, Craig Montell. TRP and Rhodopsin Transport Depends on Dual XPORT ER Chaperones Encoded by an Operon. Cell Reports, October 2015 DOI: 10.1016/j.celrep.2015.09.018

http://www.sciencedaily.com/releases/2015/10/151008152822.htm