One More Reason To Love Coffee

Coffee seems to play a large role in our daily lives, but do you know that there is a medical benefit to coffee and tea intake? Studies show that regular intake of coffee and tea reduced the risk of stroke by about 20% in the long term. So even if you are not a coffee person, green tea provides the same benefits. Although the study was only done in the 45-74 year old demographic, it seemed as though many people were to benefit from the caffeine consumption.

            The follow up of the study, which was about 13 years, included review of medical records to indicate the cause of death in those that were participants in the research. They wanted to see if those who were in their study had aliments of heart disease or stoke and their age, sex and whether or not they were a habitual smoker or consumer of alcohol. The follow up also showed that people, who drink green tea daily, as opposed to those who do not, actually had a more active lifestyle. It is not conclusive, but people are were known for green tea consumption are more likely to be physically active than those who do not drink green tea.

          The reason for green tea’s benefits comes from an antioxidant called catechins, which can also be found in chocolate made with real cocoa. Coffee contains chlorogenic acid, which can actually be beneficial for preventing stoke by reducing the risk of Type II Diabetes.  The reason that green tea and coffee is beneficial for cardiovascular risk reduction is that it helps in the reduction of blood clots. Further research could help scientists determine other benefits from the consumption of coffee and tea. There have been studies in the past, but the results were not conclusive because they did not factor in cigarette smoking, which can have a negative impact on preventing cardiovascular disease. Hopefully we will see more updates on this study and find out what other benefits we can get out of coffee and tea.

So get out there and drink more coffee and tea!

Posted by Alicia Champagne (1)

Proper Vitamin-D Levels May Lower the Risk of Diabetes

Type II diabetes is becoming more common as obesity rates in America continue to increase. Children and teens across the country struggle to control their blood sugar levels, which puts them at risk of developing the disease. But what if there was another factor affecting the blood sugar of these kids that we've been missing?

University of Missouri researchers have recently found a trend in 35 pre-diabetic obese children who were all receiving treatment in the MO Adolescent Diabetic Obesity Program. Each one of them had insufficient or deficient vitamin D levels, along with similar diet and activity levels. The participants were either given a high vitamin D supplement or a placebo which they took every day for six months. Those who took the vitamin D supplements alone received a response nearly as powerful as what the researchers have seen using a prescription drug. The participants had a decrease in insulin levels which led to better glucose control without changing their body weight, dietary intake, or physical activity.

It hasn't been recommended for obese children and adolescents to take the dosage of vitamin D distributed in the study, but rather take a deficiency test and determine if that is a factor which may be contributing to a risk of diabetes. If so, they should take the recommended amount of vitamin D supplements as a natural and inexpensive way to reduce their risk of developing the disease and lower their blood sugar. Vitamin D deficiency is common, but it affects those who are obese more. This is because they process vitamin D up half as efficiently as normal-weight people. Vitamin D isn't processed as easily because it gets stored in fat tissues, which means they need to consume more than others to maintain the right level of vitamin D.

 Many patients suffer through the side effects of their prescription drugs, and the fact that vitamin D is healthy for your body makes it a much better choice. I think this is a breakthrough especially since there is a natural way to correct the deficiency and lower blood sugar. Vitamin D also helps maintain healthy bones, muscles and nerves, and can be obtained by just playing outside for a little while per day!

Lindsey Dugas (1)

Clean Up Time

Humans, as a whole, have not exactly left a subtle footprint on the planet. The mass of waste that we have produced in our short stint as the planet's dominant species is nothing short of staggering. Through this endeavor we have kind of painted our selves into a corner. The amount of trash in our immediate area is starting to show that it is not benign, and that it will not tolerate much further ignorance. The first, and main, issue is concerned with the sorry state of the oceans. The second, and slightly less threatening but equally important, issue is the large amount of man made junk orbiting the earth. It has come to the point where ignoring both of these large floating mounds of waste is causing all kinds of problems for people, or at least enough problems to stimulate the search for an efficient solution. Not surprisingly, such similar problems have yielded similar solutions.

The more immediate threat, the trash in the oceans, has been one of our largest food sources as a species for an inestimable amount of time. However, we have not respected it as such, dumping trash by the ton and over-fishing many whole ecosystems to extinction. Over-fishing is a big enough issue that it might need a couple of different solutions, so we are going to steer clear of it for now. After years of missteps, the first movement towards what may be an elegant solution is revealing itself, and it comes from a field of technology known for some far more sinister leanings. The ethical argument over the use of unmanned drones in war has been something of a hot button issue in the news lately. Thankfully the advanced technology has shown useful in a project that is way easier to get behind. The basic idea is to clean the oceans with a machine that functions as an unmanned drone, or more accurately a whole fleet of them. Designed by Elie Ahovi, the machine is basically an over-sized net, which is propelled by motors attached to a ring like “mouth” at the front. Also contained are sensors which will track and try to catch plastic and other trash, while avoiding wildlife becoming ensnared. One unit has enough power to stay deployed for up to two weeks. While this is still a new invention and there are likely some bugs, it shows the potential to do a lot of good in a large scale operation.

While less threatening, the trash floating around the earth in orbit has been causing countless problems for the various interests trying to put their own equipment in that space. The small pieces of shrapnel accumulated from our decades in space can move at huge speeds and break pieces of expensive equipment put up their by governments and businesses. With people starting to complain, the Swiss have taken it upon themselves to try to fix this. While it will probably be less independent than the ocean drones, the “janitor” satellite project currently referred to as clean space one will likely work in basically the same way. The unmanned satellite will collect debris as it orbits the earth in order make installing future satellites more financially viable and prevent debris from falling back to earth.

To be frank, both of these are lazy solutions. But, sometimes that is exactly what you need when a problem seems insurmountable. Also the word lazy does not speak to the extreme creativity and ingenuity of these solutions. One man's lazy is the next's efficient.

http://www.dailytech.com/Swiss+Unveil+CleanSpace+One+Satellite+to+Clean+up+Space/article24014.htm

http://www.nexpected.com/2013/03/cleaning-up-seas-with-drones.html

http://elieahovi.com/

Posted By Hunter Alexander (1)

How is Darwinian Medicine Useful?

When I think of the evolution of disease and other complications that have accumulated over time, I have always thought of these issues as harmful to the human population. In the article How is Darwinian Medicine Useful, written by Randolph M Nesse, these ‘complications’ have actually been the product of Natural Selection within the populations in order to benefit human survival and the overall increase in reproduction. For instance currently there is an obesity problem in the United States stemming from a craving of sweet, salty, and fatty foods and unwillingness to exercise. According to Nesse, these characteristics of humans have come from our origins in Central Africa where these foods were rare and full of energy and thus were consumed in large quantities when found. Also our ancestors had to walk for long periods during the day to find food so any excess exercise had to be conserved in order to survive. Human diseases and their characteristics have also been categorized as ‘human imperfection’. Symptoms of diseases like coughing and a fever are not the body’s way of breaking down but its evolutionary attributes developed in order to keep the human body healthy. These responses are not problems themselves but represent the body's attempt to remedy a problem. That’s why modern medicine is needs to work with these symptoms so as not to block them but to help the course of the disease. Every flaw within us has some evolutionary purpose that has been developed over hundreds of thousands of generations and is continuously being selected for over the future generations. There are many reasons why our body has never stopped evolving One important reason is that natural selection does not influence organisms for better health or longer lifetimes. Instead its main goal is to maximize reproduction, even at the expense of a shortened life span. So over the years there have been some diseases that benefit fecundity but may bring about an uncomfortably short lifetime. Therefore it is important to work with Darwinian medicine to look at the past and present courses of diseases and the evolutionary paths it has taken to get there. Then, after answering those questions it is important to look into a way of guiding these diseases to extinction.

Posted by Celina Keating (1)

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1071402/

Xenopus's Secret Talent

http://www.euroherp.com/Resources/Trips/Xenopus_laevis_02.jpg

Know of anyone who thinks they are pregnant but does not want to buy a pregnancy test? Well no need to buy a pregnancy test, when you can but a frog that can give you your results, and make a pretty cool pet!  Xenopus laevis can do both! I learned about this in one of my other classes and found this interesting but had no real idea as to how this came about or how it works.

Frogs are not the first animal to be used as a pregnancy test. Other animals that have been tested and found to work are mice and rabbits. But they could not give results like Xenopus, instead they had to be killed, dissected and have their ovaries examined.

It turns out all one has to do is inject some of their urine into the dorsal lymph sac of a Xenopus laevis female, and check a few hours later. If the Xenopus laevis lays eggs between eight to twelve hours later, then that means you are pregnant. If you so happen to buy a male Xenopus, then the frog would respond by producing sperm instead of eggs. This test works because urine that belongs to pregnant women contain the hormone human chorionic gonadotropin (hCG), and most standard pregnancy tests that are used today rely on whether this hormone is present or not.

This finding is not new, in fact it has been used since 1930, but I still find this pregnancy test more intriguing than simply just peeing on a stick. But maybe that is just me. I am not encouraging or discouraging anyone from getting pregnant, but this would be a cool idea on figuring out if you are pregnant. As an extra bonus you get a pet African- clawed frog as well!!

Posted by : Cynthia Bui (1)

Promising New Treatment with Stem Cells

Promising New Treatment with Stem Cells

     A new study has found that stem cells taken from amniotic fluid have the potential to treat infants with Necrotizing Enterocolitis. This disease is characterized by cell death (necrosis) of the intestinal lining. There is no definitive cause, but prematurity, blood transfusions, and concentrated formulas all increase the risk of this disease. NEC has roughly a 15 to 20% mortality rate.

      Great Ormond Street Hospital funded the UCL Institute of Child Health to conduct a study that researched treatments of NEC. Breast milk and Probiotics were both shown to help with NEC, but their effects are limited, and all too often NEC requires invasive techniques such as surgery to remove dead tissue or a transplant of healthy tissue.

     Rats afflicted with this disease were separated into three groups: one group was left untreated, one that was treated with stems cells extracted from their own femurs, and one group that was treated with stem cells from amniotic fluid. The rats treated with stem cells from amniotic fluid were found to have a much higher survival rate than those of the other two groups after only a week of treatment. MRIs revealed significantly decreased inflammation.

     Upon further research, amniotic stem cells were found to aide the intestines differently than bone marrow stem cells. Instead of simply regenerating tissue, they released growth factors that reduced inflammation and enhanced new development of tissue. They exhibited actions of repairing the source of disease.

     This is the first study to show the treatment potential of amniotic stem cells in intestinal pathology. As more is learned about the process of how amniotic stem cells repair tissue, treatments will evolve and hopefully more invasive techniques will decrease.

posted by Ashley Sterpka (1)

Sources:

http://www.medicalnewstoday.com/releases/258168.php

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002133/

Can You Handle The Slippery Dick?

This slippery guy can commonly be found all over including the Western Atlantic and down from North Carolina to Bermuda and Brazil. This species can normally be expected to reach an impressive size of around 30 centimeters in length (about 12 inches), juveniles obviously being much smaller than full-grown adults. Gentlemen, old and young, have been known to compare the size of their Slippery Dicks in public, usually on the shores of the ocean, (all in good fun of course). But beware when attempting to handle the Dick, don’t startle it or grab it too tight for it can produce a slimy, mucus-like coating when alarmed or frightened (which is a defense mechanism).

Oh I apologize; I would like to clear up any confusion this may cause because the minds of kids these days are going down-hill. This is a biology course, and the Slippery Dick is of course a species of fish, not human genitalia; sickos.

Anyways moving forward, the Slippery swims with its tail down like it is being dragged along behind it and has a skinny, slim body which aids in swimming at quick speeds. They also come in several shades with a large variation in colors consisting from light purples and yellows to anything like shades of green and brown. Younger Dicks tend to be white, while the adults gain color and have a large, dark stripe running along the whole body from the tail to the eye. There is another stripe that runs on the underside of the body that doesn’t tend to develop until adulthood for the fish. Interestingly enough, all Slippery Dicks are protogynous hermaphrodite, meaning they are all born female, and as they develop some make the sex shift to become males. When mating, the (now) male Slippery Dick acts in a very masculine way indeed. The males form what is known as a lek. This is a kind of territory in which the males show off their prowess. If you think of a fishy kind of WWF, then you are fairly close to the mark. Wondrously, the male Slippery Dick comes in phases, known as initial and terminal. The initial phase male Slippery Dicks are not aggressive or territorial. They will spawn together with a single female. The older, terminal phase Slippery Dick, however, will only mate with a single female a time.

Fun fact: the Slippery Dick is supposedly quite tasty and there are apparently numerous ways to eat them. Bars and shacks have been known to be named after these fish including a number of events: weirder events have included the spotting of women carrying a Slippery Dick in each hand, followed by swallowing the poor fellas simultaneously. 

Nick Mulone

A Key to Happiness

Have you ever wondered what makes you happy? Is it power? Money? Getting A from Biol 312? Or like most other things, is it something in your head? According to a group of UCLA scientists, the main key to your happiness is a neurotransmitter called hypocretin. The release of hypocretin increased when the subjects were happy. Its release decreased when the subjects were sad.

This finding can be used for both depression and the study of narcolepsy because depression and the sleep disorder often happen together. The study, from last week’s Nature Communications, looked at the release of two peptides in the brain: melanin-concentrating hormone, or MCH, and hypocretin. Hypocretin levels increased when we were waking up, while MCH levels increased during sleep.

To investigate the relationship between hypocretin, depression and narcolepsy, the researchers followed eight epileptic Ronald Reagan Hospital patients whose brains were already being monitored by implanted electrodes. They measured the release of hypocretin and MCH while they watched television, engaged in social interactions such as talking to physicians, nursing staff or family, ate, and experienced sleep-wake transitions. The patients rated their moods every hour in a questionnaire.

The researchers found that hypocretin levels were not linked to arousal in general. Yet, they were highest during positive emotions, anger, social interactions and awakening. Also, the levels remained much lower during pain or sleep. In contrast, MCH levels were highest when they were falling asleep or just after eating, and lowest when they were experiencing pain or interacting socially.

Some drug companies are developing the usage of hypocretin antagonists in sleeping pills, but this study suggests that that would alter people’s mood as well. Along with previous research, the results “suggest that hypocretin administration will elevate both mood and alertness in humans,” according to senior author Jerome Siegel, a UCLA psychiatry professor who studies sleep.

Posted by Setareh Sepasi (3)

Father's Age Effecting Children's Genetics

After reading this article on Genetic damage and a Father's Age It was not surprising to me that scientific research is finding out that as men age there is a higher rate of mutation in their sperm. Since men produce large amounts of sperm and women produce minimal amounts of eggs as compared it was also not surprising that men have a higher mutation rate then women. And when we think about the fact that as women age they are more likely to pass on mutations to their children as they age, (for example: Downs syndrome), then it should not seem unreasonable that men also have an increase in mutations that they can pass on to their children as they age.  However I do not know that there is that much of a difference in older mens' offspring that would be noticeable, because the article states that only 10% of the mutations are damaging. So will it really make that much of a difference?
In our society today the average age of people having children is increasing; according to the article the average age of fathers at conception is now 33 whereas in 1980 it used to be 28. I do not believe that the information portrayed in this article is likely to stop men from having children when they are older, if they want them.
The article also mentions women having their eggs frozen for later viability use; then mentions the future possibility if men having their sperm frozen for use to have children later in life.  I do not think that this is something we will be seeing in the future. What do you think?
Tonya Sulham (3)

Recent Mummy Findings Not a Guideline For Your Diet

It seems like every month a new diet or "super-food" is being pushed by the media. Usually the logic behind these diets is rooted in some type of pseudoscience, or a very liberal interpretation of a newly published article.  Recently nutrition, health, and fitness news outlets are all offering their own spin on a newly-published study involving heart disease in mummies.

In the study, researchers performed whole-body CT scans on 137 mummies from four ancient populations – Egyptian, Peruvian, Puebloan (southwest America), and Unangan (Aleutian Islands). They analyzed the images for signs of atherosclerosis, or hardening of artery walls due to buildup of cholesterol and fatty-acid laden plaque. This was evidenced by the presence of calcified plaque on the mummies’ artery walls, or if a given artery was not persevered through the years, along the path where it was expected to run. Interestingly, atherosclerosis was found in 34% of 137 mummies: (38%) of 76 ancient Egyptians, 13 (25%) of 51 ancient Peruvians, two (40%) of five Ancestral Puebloans, and three (60%) of five Unangans.

                

Atherosclerosis has been estimated to affect up to 35% of modern Americans. Wait a minute… So even with our modern diet, full of the countless flaws nutritionists would love to tell you about, our arteries are just as bad as the ancients? As much as I would enjoy telling members of the so called “Paleo cult” that their lifestyle changes have all been in vain, I don’t think we have close to enough information to exonerate the modern diet.  

               

I don’t think the 34% vs 35% figure tells us as much about the relationship between diet and atherosclerosis as some nutritionists and health enthusiasts would like to believe. Instead, it merely points to our incomplete understanding of the causes of plaque-buildup and how it relates to aging and other factors. For example, studies have shown that frequent infection, as well as stress, can lead to increased atherosclerosis. Ancient people obviously had a harder time dealing with infection without modern drugs and medical knowledge. The role of smoke inhalation needs to be addressed too; it's noted in the article that many of the non-Egyptian mummies were exposed to high levels of smoke from non-ventilated cooking fires, a prominent risk-factor in developing atherosclerosis (which is present in the modern world in the form of cigarettes).

               

 In other words, don’t throw out your vegetables and park yourself on the sofa just yet. Although this study has given us new insight towards the development and history of heart-threatening atherosclerosis, it’s not quite the nutritional “get out of jail free” card that many sources are making it out to be. 

Credit for picture:

Mummy: Jose and Roxanne 

Joseph Starrett (3)

Food-Lovers Listen Up!

http://www.visembryo.com/story1395.html

          As we all may be well aware of by now obesity is quickly becoming a dangerous trend among the greater population of the United States. We have always been told that being physically active and eating healthy would be the key to physical health, however, regardless of how simple being physically fit sounds, the United States still finds itself battling rapid increases in obesity. So, now science may be coming to the rescue and may hold the key to sequestering this growing trend. Recently, researchers have discovered a gene that when deleted prevents obesity in mice on high fat diets, which now researchers are hoping can be replicated in humans to decrease these rates of obesity. Don’t you wish you could eat anything you wanted and not have to worry about the calories or where on your body that food will go?

            So, food-lovers listen up…you may finally be able to enjoy all the food in the world without dreading gaining a few pounds. Research lead by Prof. James McManaman, Ph.D., vice-chairman of research for Obstetrics and Gynecology at the University of Colorado School of Medicine, has discovered a gene, Plin2, which produces a protein that regulates fat storage and metabolism in mice and humans that when deleted prevents mice from being obese, even when placed on a high fat diet. Numerous advantages have been revealed with the deletion of this gene, firstly, mice without the gene ate less and were more active, secondly, fatty liver disease usually related to obesity and commonly found in humans and rodents was undetected, among others. This study has also found that without the presence of the gene, fat can be metabolized faster, which is something many of us humans struggle with, from dieting to supplements to help increase our metabolizes, deletion of this gene may be the answer to our problems.

            This type of research could open so many doors into how to control rates of obesity nationwide and could ultimately help make the U.S. healthier as a nation. Since this deletion has shown that mice become more active and eat less, maybe the same thing would happen for humans and we could actually become physically fit, with a little help from science! From this article the only questions that really came to mind is how this gene deletion would affect human physiology and whether deleting the gene would cause some sort of adverse affects on other parts of our intricate system? It obviously seems as though much more research must be done before this can come close to being tested on humans, but it sure does sound promising!

Posted by Gabrielle Wertheim (3)

Gender Bending

This article talks about different ways in which bizarre sex strategies occur within different types of species. It’s typical that a female would carry the eggs and the male species would donate the sperm, but according to recent study, the exact opposite is happening. Scientists have found that in certain species, the male is caring for the offspring during and after reproduction.

In male pipefish, the males actually pick their mates based on size. The larger the female, the more likely he’ll want to mate with her. This occurs because the male pipefish is looking to create stronger offspring and the size of the female fish could potentially mean more successful fertilization and reproduction. Once he finds the right sized mate, the female pipefish will transfer her eggs into a special pouch in the male pipefish and wait for fertilization and reproduction to occur.

To prove that males prefer a larger mate, scientists mated a male pipefish with both a small and large female pipefish. The results were uncanny. Not only did the male fish carry more eggs when mating with a large female, but also the care taken for those offspring was much greater. The survival rate of the unborn offspring from the large female pipefish was higher than those that came from the small female pipefish. The evidence shows that males favor the eggs of the larger female and pay better attention to their care during fertilization and maturation.

Scientists believe that these male pipefish base their reproduction off of their own chance of survival. It’s believed that the male pipefish have a higher chance of nourishment and survival from a larger brood of fish versus a small brood. When the fish carry the small female’s eggs, they are spending their resources on making them stronger instead of spending the resources on themselves. Interesting, huh?

Kimberly Ty (3)

Edited my blog (2nd paragraph)

Increasing Neuroplasticity Through Gene Knockout

            

            If you ever noticed how much more difficult it is to learn a new language as you age, you can realize how less adaptive the brain become as you get older. Adults have a more difficult time learning new concepts than children do because children's brains are more flexible. The Nogo Receptor 1 gene has been shown to lead to the maturation of the brain, decreasing its neuroplasticity. With this gene identified, scientists wanted to see if the adult brain in mice can change back to the more plastic brain function of adolescent mice through gene knockout. When researchers blocked this gene in aging mice, they noticed that these mutated mice continued to have juvenile brain function even into adulthood. Even more interesting is that adult mice that had this gene blocked had their rigid adult brain revert back to a more malleable juvenile brain.

            The inhibition of the Nogo Receptor 1 gene can have some potential human applications including overcoming traumatic experiences, recovering from brain damage, and having better learning abilities. People who suffer from brain injuries like stroke most go through rehabilitation to redevelop certain movement skills. Brain-injured mice that had this gene blocked were able to learn motor tasks faster than wild type mice. This indicates that stroke patients could potentially have quicker rehab times if the gene is blocked in humans.

Another interesting discovery was that Nogo receptors lead to slower memory loss. Mice that had this gene blocked had a faster ability to forget stressful memories. This discovery could potentially help people with post-traumatic stress disorder because it could help sufferers get past traumatic events. The only question that I had was how would the inhibition of the Nogo Receptor 1 gene affect personalities in humans?

Posted by Poya Jafari (2)

SEX DIFFERENCES in the GUT MICROBIOME DRIVE HORMONE-DEPENDENT REGULATION of AUTOIMMUNITY

 

Usually one is told to abstain from germs, however exposure to some germs and awareness of what one is at risk for depending on their sex can help them identify their resistance to Type 1 Diabetes. An individual’s susceptibility to autoimmune disease is caused both by environmental and genetic factors, but what is it about germs and whether one is a male or female that influences an individual’s susceptibility to autoimmunity? Is it safer to live in a germ- free environment or a non- germ- free environment? Do bacteria pose a mutualistic effect on a host metabolism?

According to a recent article, it has been shown that being a female and living in a germ- free environment increases ones chances of obtaining Type 1 diabetes.  Several tests were performed that proved this.  These tests show that because females have a different microbiome, they are more likely to get diabetes than a male.  Furthermore, having a higher level of testosterone leads to a diminished likelihood of obtaining diabetes.

These tests are important because they help patients and doctors determine how great of a risk the patient is for diabetes and therefore having a plan implemented to prevent or treat the disease. Additionally, doctors and patients need to be aware in the early stages of life about this possibility because early- life exposure to microbiota determines levels of sex hormone which therefore effect one’s ability to protect against diabetes. Thanks to the current testing and research we can better regulate the fate of individuals with high genetic risk.

 

Posted by Marshall Moini (2) 

Amps and Neurotransmitters: The Story of Kiss and Run Exocytosis

    

            If you wanted to study the kinetics of neurotransmitter release at neuronal synapses, how would you do it? There has been a traditional answer to this question in the research community. Stick a recording electrode in the post-synaptic neuron, stimulate the pre-synaptic one with another electrode, and record the electrical response of the post-synaptic cell. However, indirect approaches like this limit our ability to detect what is really going on in pre-synaptic active zones. An innovative electrophysiological technique can address this problem. It’s known as amperometry, and this is how it works. Say you want to study the release of dopamine from neurons. Place a carbon fiber electrode in solution just over the pre-synaptic active zone. Then, generate a voltage of +700mV in the electrode. This is a high enough voltage to oxidize dopamine molecules that come into contact with the electrode, and thus generate a current in the electrode. The magnitude of this current is therefore proportional to the amount of dopamine released. This allows for direct recording of the amount of dopamine released from synapses over time in response to stimulation.  Amperometry has enabled a team of scientists at Columbia University to shed light on the nature of the synaptic release of dopamine.

            If you are already familiar with the basics of synaptic transmission, you know that depolarization of pre-synaptic cells causes the release of neurotransmitter via fusion of synaptic vesicles with the pre-synaptic membrane.  However, this fusion isn’t always complete. It is thought that often, especially with vesicles that contain small molecule neurotransmitters such as dopamine, vesicles may partially fuse with the membrane and then separate and close up again. Sometimes vesicles may repeat this partial fusion and dissociation, known as “kiss and run exocytosis”, several times in quick succession. Using amperometry, the researchers as Columbia were able to provide convincing evidence that this is the primary means of exocytosis in dopaminergic neurons.  Using neurons cultured in vitro, they recorded dopamine release in response to depolarization. Their recordings showed two distinct current patterns. Sometimes, single spikes of current were recorded, termed simple events by the researchers. Other times, they recorded repeated spikes of current, with the initial spike being comparable in amplitude to the single spike event, but the subsequent spikes always decreasing in amplitude over time. These were labeled complex events. The researchers interpreted these recordings as evidence of kiss and run exocytosis. The single spikes represented instances of single transient fusion of vesicles with the membrane. The compound spike patterns were thought to represent repeated fusion of the same vesicle with the membrane. The continual decrease in current would correspond to the slowly depleting dopamine stores in the vesicles as it continually fused and resealed, releasing more of its neurotransmitter with each fusion event.

 Figure: diagrams c and d represent current recordings of simple and complex events, respectively

            This study provides solid evidence of the prevalence of kiss and run exocytosis in dopaminergic neurons. The major limitation of these results is that these recordings were performed using cultured neurons in vitro. It will be interesting to see if these same results hold true for neurons in vivo. However, this study still lays the groundwork for uncovering the intricate details of vesicle fusion in neurons. Soon we may see if other types of neurons also use this pattern of release and to what extent, as well as what functional advantage it may convey to these neurons. 

Posted by Sean McDougall (2)

Tis the Season for Ticks!



 

 

 

Days are becoming longer, birds are starting to sing, and we will soon see tulips begin to sprout. With spring quickly approaching a less desirable time is upon us-tick season. If you are an outdoors person or own pets you know that these blood sucking parasites can be quite a nuisance. Annoying as they may be ticks also transfer illnesses such as Lyme disease.

Researchers from Tufts have identified a new tick-borne disease caused by the spirochete bacteria Borrelia miyamotoi.  The bacteria is less prevalent that the Lyme causing bacteria, with only one confirmed case in the U.S.  But Tufts research states that “B. miyamotoi may be an under recognized source of human disease, especially in regions such as the northeastern United States, where Lyme disease is prevalent”. Up until recently, there was little data or research directly linking the bacteria to human disease.     

If you tend to frequent the ticks habitat you may want to take extra precautions as warm weather approaches. Wear long sleeved shirts and pants, and avoid areas of high vegetation. Examine yourself after being outdoors in places ticks like to hide such as your armpit, bellybutton, behind the knees, and other tick loving areas of the body. Check pets before letting them loose in the house and treat them with a veterinarian approved tick preventative. Please remember- ticks will just sit and wait for a blood meal to come along!

 

Angeline Latsch (2)