In Vitro Fertilization: The Laboratory Baby Boom

Right before midnight, on July 25, 1978, Lesley and John Brown welcomed the birth of their little girl. Her name was Louise Brown, and she was born in Oldham, England. Three years later, across the world, Judith and Roger Carr welcomed their second child, Elizabeth, in Norfolk, Virginia. Two baby girls born in two different countries. Unlike millions of other babies born during that time span, Louise and Elizabeth each graced the covers of national magazines after their birth. What made these two babies so special? They were the first babies conceived using in vitro fertilization (IVF) in England and the United States.

            Since Louise Brown’s birth, over six million IVF babies have been born throughout the globe. IVF is a method that helps couples with fertility problems to conceive a child. Simply put, instead of fertilization occurring within the body, it occurs in the lab. This might be needed if a woman has damaged fallopian tubes, those tubes that connect the ovaries to the uterus, since this prevents eggs being fertilized and embryos reaching the uterus (where a fetus develops). Other scenarios can direct couples toward IVF such as problems with ovulation (egg production), sperm production, genetic disorders, or other conditions affecting reproduction.

A sequence of general steps is followed during IVF. Since eggs are required to form an embryo, synthetic hormone treatments are given to stimulate the production of multiple eggs at one time (typically, only one egg is released per month). This process is referred to as ovarian stimulation, can take 8-12 days, and increases the chances of fertilization. Yet, there are many possible side effects of the intense hormone treatments, which all doctors should educate their patients on. Ultrasounds and estrogen tests are used to monitor the eggs throughout this process. Once the eggs look ripe for fertilization, a shot is administered to commence the eggs’ release. About 36 hours later, the eggs are sucked up using a thin needle and suction (fortunately the woman is sedated). This process can result in several eggs being collected in about 20 minutes.

Once eggs are retrieved, they are fertilized with the father’s sperm in a lab. As you might expect, sperm is usually collected in a simpler method that does not require hormone treatments. Once the eggs are fertilized, and now referred to as embryos, one embryo (or sometimes multiple – to increase the likelihood of success) are implanted into the uterus to continue developing. In some cases, embryos are given about six days to develop in the lab before they’re tested for genetic diseases and chromosome number. This gives doctors greater confidence that implanted embryos do not carry common diseases or chromosomal abnormalities.

While IVF is usually associated with couples, it’s important to note that eggs or sperm can come from donors. Additionally, embryos can be implanted into a gestational carrier: a woman that carries the baby to term.

The goal of IVF is to conceive a healthy baby. Since its initial success with Louise Brown, millions of babies have been conceived using IVF, and it’s easy to imagine the joy that IVF has provided for families throughout the world. 

List of Sources

1.     The Telegraph. “Louise Brown, the first IVF baby, reveals family was bombarded with hate mail.” Victoria Ward. July 24, 2015. www.telegraph.co.uk/news/health/11760004/Louise-Brown-the-first-IVF-baby-reveals-family-was-bombarded-with-hate-mail.html

2.     WWW.mayoclinic.org (search for “in vitro fertilization” at top of screen. Then, click on top search result “In vitro fertilization (IVF) – Overview – Mayo Clinic.” See information in “Overview” and “Procedure Details” tabs.)

3.     WWW.columbiafertility.com (search for “typical IVF timeline” at top of screen. Then, click top search result “The Typical IVF Timeline: 6 Steps You Need to Know.”)

4.     WWW.urmc.rochester.edu (search for “IVF step by step” at top of screen. Then, click top search result “IVF Step-by-Step.”)

Sperm Storage and Cryptic Female Choice

The above video from Science News shows two male cuttlefish violently competing for a single female to mate with. The second "intruder" male arrives to the scene after the first male mates with the female. The two males engage in a violent, inky fight, and the female eventually flees the scene. One explanation for why the first male remains to fend off the intruder, even after successfully mating with the female, is that female cuttlefish store sperm. A female can store packets of male sperm from multiple matings. This suggests that even after mating with a female, a male might hang around to prevent other males from mating with her, as seen in the video. This increases the chance that the male's sperm is selected for fertilization, instead of another male's genetic material, and helps him secure his paternity.

Cuttlefish represent just one type of animal that is capable of sperm storage. Various species of insects, birds, and reptiles are also capable of this. In fact, females of such species can select which male's sperm they want to fertilize their eggs in a process called "cryptic female choice." This allows females to select sperm that can increase offspring quality and number.

VSGC Conference

Yesterday I attended the annual Virginia Space Grant Consortium (VSGC) Conference. In association with NASA, the VSGC generously awards college students, at both the undergraduate and graduate level, funding to help with their research. As a graduate research fellow, I was invited to present my research and also hear about a lot of interesting research being done by others.

The topics ranged from Aerospace and Astrophysics to Chemistry and Biology. The students presenting were just as diverse as the research they discussed. The mix of students, professors, NASA engineers, and other industry professionals made for interesting conversations, and I'm sure everyone left the conference with new ideas. Some of the exciting research topics I learned about are described here:

How giant molecular clouds' magnetic fields allow for the formation of stars. 

How mammoth fossils are less degraded in different environments than others (permafrost being the best for maintaining fossil integrity).

How a new radiation-blocking material is being designed for potential use in space.

How some proteins can remain stable in extremely harsh environments (such as potential environments in space). 

How the properties of spider silk are being tested using rare, high-speed cameras.

The Sterilization of Mosquitoes

Many infamous viral disease such as malaria, Zika, dengue, West Nile, and yellow fever are all carried and transmitted to new hosts by mosquitoes. For many years researchers have been looking for ways to prevent the spread of these dangerous viruses, and they often target mosquitoes. One method is to sterilize mosquitoes, thus reducing the amount of carriers. Male mosquitoes can be sterilized by infecting them with a certain bacteria (Wolbachia) that modifies their sperm. When a Wolbachia-infected male mates with an uninfected female mosquito, his sperm kills the eggs after fertilization. When the infected male mates with an infected female, her modified egg is compatible with his modified sperm, and the eggs survive.

While this sterilization method is being used, scientists didn't really understand all the mechanisms underlying how it works. To understand why this bacteria causes sterilization, a group of scientists from Vanderbilt University pinpointed two genes in Wolbachia called cifA and cifB and inserted them into male fruit flies. They found that these males could no longer reproduce with normal female flies, but just like in the mosquitoes, they could still reproduce with infected females. The infected females "rescue" the modified sperm which reminded scientists at the Yale School of Medicine of antidotes and toxins. They used simple yeast cells to test this hypothesis and put the "toxin" gene into the yeast, which resulted in the yeast cells dying. On the other hand, when they put both the "toxin" and "antidote" genes into the yeast, they survived.

These experiments in both fruit flies and yeast mirror what is happening in mosquitoes. Since the discovery of this gene pair, researchers have considered adding extra copies of these genes into bacteria, creating a "super Wolbachia" that more potently sterilizes the mosquitoes. Yet, this could "essentially crash the population" said coauthor of the fruit fly study Seth Bordenstein. While the creation of bacteria with multiple copies of the genes has not yet been attempted, this research unveils the genes responsible for the sterilization of mosquitoes, and helps fight against the spread of viral diseases.

Link to news article: https://www.sciencenews.org/article/bacteria-genes-offer-new-strategy-sterilizing-mosquitoes?mode=topic&context=87

Gene-Editing Policy

A group of experts recently met to discuss the use of gene-editing. This group from The National Academies of Sciences and Medicine issued a recommendation on Feb. 14th stating that altering germline cells (such as eggs, sperm, and embryos) should be allowed if the editing cures genetic diseases, but does not enhance health or abilities. Germline cells are reproductive cells, and any genetic modification in these cells will be passed on to future generations- a very useful tool for curing a disease in not just one person, but their future offspring. Co-chair of the recent panel Alta Charo, says "We are not trying to greenlight heritable germline editing...We're giving it a yellow light." In other words, the panel of experts is trying to find the special circumstances in which the use of germline editing is justified by a very great need for its healing potential. Some examples of these special cases would be curing cystic fibrosis or Huntington's in someone, and thus eliminating the disease from any of their future offspring.

This recent recommendation, for allowing germline editing in certain cases, goes against a global summit's previous recommendation that gene-editing should not be used in the germline. Many scientists fear that allowing any form of germline editing would open the floodgates for other, less necessary, applications (such as designing a baby's eye-color or increasing athletic ability). Marcy Darnovsky, director of the Center for Genetics and Society in Berkeley, says “Once you approve any form of human germline modification you really open the door to all forms...I’m feeling very unsettled and disappointed by what they are recommending.”

Clinical trials that would produce heritable changes in the human genome are currently banned in the U.S. Still, the debate about germline gene-editing rages on, and this recent recommendation may pave the way for a change in policy.

Link to Science News article:
https://www.sciencenews.org/article/human-gene-editing-therapies-are-ok-certain-cases-panel-advises?mode=topic&context=87

Chimera: Hosts to Other Species

In Greek mythology, the Chimera was a fire-breathing hybrid creature with parts from more than one animal (imagine a creature with the body of a goat, dragon wings, and a lion head). In the scientific world, animal hybrids are called "chimeric" and receive their name from this mythical creature, but unlike their namesake, exist in reality. One area of research involving the use of chimeric animals has the ultimate goal of growing human organs in these animals, and then transplanting them into humans.

While this research is still very young, several studies of chimeric mice, rats, and pigs, suggest that using one organism to grow an organ of another species, is a viable method for curing disease. One particular study published in Nature, showed that mouse pancreases could be grown in rats. The healthy insulin-producing cells from the mouse pancreases were extracted from the chimeric rats, and transplanted into diabetic mice, which cured the mice of diabetes. The transplanted cells allowed the mice to maintain normal blood sugar for more than a year, giving scientists much hope for the future of this research.

In another study, pig embryos were injected with human stem cells, with the hope of using pigs to grow human organs for disease treatment. Unfortunately, the researchers found that the human cells likely interfered with normal pig development, since only a small percentage of the pig embryos were capable of continuing development for about 28 days. Currently, scientists are working to improve the growth of human cells in pig embryos, and there is hope that one day humans can benefit from this medical technology using chimeric pigs.

Link to news article:
https://www.sciencenews.org/article/mouse-cells-grown-rats-cure-diabetes-mice?mode=topic&context=87

Chimeric mouse embryo containing rat cells (shown in red)

Synthetic DNA Bases

Life's natural genetic code is made up of 4 DNA bases represented by the letters A, T, G, and C. These 4 bases pair to form base-pairs (A-T and G-C). These base pairs have been rearranged to create all types of organisms (penguins, bears, whales, humans, plants, bacteria etc.). In other words, life as we know it is made from these 4 DNA bases.

Scientists from The Scripps Research Institute in California have created 2 new DNA bases they call X and Y. These new bases form a base-pair and have been incorporated in an entirely new organism. The new type of bacteria they created still contains the usual A, T, G, and C bases, but also has the new bases (X and Y) in its genome. This new bacterium has been called the first "semisynthetic organism."

While this new bacterium has no practical applications at this point, the lead researchers on this project suggest that these new bases can allow single-celled organisms to take on new properties, potentially helping scientists create new drugs. We can be comforted by the fact that this technology is only intended for use in single-celled organisms, and we won't be seeing these new X and Y bases showing up in more complex organisms.

Link to article about this research:
https://www.sciencedaily.com/releases/2017/01/170123214717.htm

Sight Restored Using Stem Cells

Stem cells have an amazing potential to heal, but a challenge is ensuring the transplanted cells survive long enough to work. Long-term studies of stem cell therapies have been performed in a variety of model organisms. Notably, researchers from the Buck Institute have provided one of the first demonstrations of long-term stem cell therapy efficacy. They transplanted photoreceptors (cells for receiving light signals), derived from human stem cells, into blind mice and observed long-term vision restoration. They found that even 9 months after injection, the mice were able to perceive light signals (something they were completely incapable of prior to the treatment).

This awesome example not only shows the great potential of stem cell therapies for healing, but can help scientists further develop stem cell therapies that circumvent immune rejection. Dr. Lamba, senior author on the paper, says "That finding gives us a lot of hope for patients, that we can create some sort of advantage for these stem cell therapies so it won't be just a transient response when these cells are put in, but sustained vision for a long time."

Link to article:

https://www.sciencedaily.com/releases/2017/01/170112141243.htm

Genome Editing Trials

For the first time, the exciting gene-editing tool CRISPR-Cas9 has been used in a human. This technology, which I wrote about several weeks ago (refer to post from Nov. 5 for more detail), allows scientists to alter DNA bases to introduce a change to any gene. The concept of altering human DNA is controversial, but the potential health applications are practically limitless. For example, if a disease is caused by a specific, known mutation, scientists could potentially alter that mutation, thus treating the disease. This technology is a hot topic among biologists, and is also currently one of the most-studied tools.

Cancer is one of the main diseases that scientists hope can be treated using CRISPR-Cas9. Because of this, the first use of CRISPR-Cas9 has been in a human patient with aggressive lung cancer. Scientists of the West China Hospital in Chengdu have altered a gene that normally prevents a cell from launching an immune response, so that the immune system is more likely to target and destroy cancerous cells. The researchers hope that after injection into the patient's blood stream, the modified cells will then start attacking the cancerous cells. 

While this Chinese trial, the first of its kind, began in October of 2016, the United States also plans to start a human trial of CRISPR-Cas9 early this year. The U.S. trial is also testing the safety and efficacy of using CRISPR technology to combat several forms of cancer. Since both China and the U.S. are launching CRISPR-Cas9 trials, some healthy competition is predicted to fuel the potentially life-saving research. Carl June, a scientific adviser to the U.S. trial, says "I think this is going to trigger 'Sputnik 2.0,' a biomedical duel on progress between China and the United States, which is important since competition usually improves the end product."

To watch a video and gain more information about this Chinese trial, follow this link:

http://www.usnews.com/news/national-news/articles/2016-11-17/gene-editing-tool-crispr-cas9-used-in-a-human-for-the-first-time

Synthetic Stem Cells

Stem cell therapies have the potential to treat many different diseases and help many people. One way these therapies work is by helping damaged tissue repair itself. Still, there are risks associated with these therapies including immune system rejection, and potentially cancerous growths. Additionally, natural stem cells are fragile, and must be treated with extreme care, which slows therapies and adds another element of risk. To circumvent some of these limitations, scientists are developing procedures that use synthetic stem cells, instead of natural cells.

Scientists from North Carolina State University, the University of North Carolina at Chapel Hill, and First Affiliated Hospital of Zhengzhou University, created synthetic cardiac stem cells, and implanted them into mouse hearts that had been damaged by heart attack. Usually, the damage that heart attacks inflict upon heart muscles are never repaired by the body. Yet, when the researchers injected the synthetic stem cells, they found that the previously damaged heart muscles were effectively repaired, and this repair was comparable to when natural cardiac stem cells are implanted.

These findings are very promising for the future of stem cell research and therapies. Compared to natural stem cells, the synthetic stem cells are more stable and can be modified for use in different parts of the body. Unlike natural cells, the synthetic versions are incapable of replicating, which reduces the risk of tumor formation. And since the synthetic stem cells are designed to bypass the patient's immune system, they are far less likely to be rejected by the body's immune system. Ultimately, using synthetic stem cells instead of natural stem cells may be more affordable and accessible, and could eliminate some of the dangerous side effects associated with stem cell therapies.

To read more about the research done here, check out the following links:

http://wallstreetpit.com/112614-worlds-first-synthetic-stem-cells-implanted/

https://news.ncsu.edu/2016/12/synthetic-stem-cells/

The Skin Gun

A whole field of research revolves around harnessing the power of stem cells to treat many different injuries and ailments. Recently, CNN released an article about a skin gun that sprays a patient's healthy skin stem cells onto severe burns. The goal is to completely heal the severe burns, much faster than typical healing, using the patient's own stem cells.

Developed by a New York biotech firm called RenovaCare, this "CellMist System" requires just about a square inch of unwounded skin. To summarize the process, the patients' healthy skin is removed, the stem cells are isolated from the other skin tissue, suspended in a water-based solution, and sprayed onto the wound where the new skin hopefully begins to grow. The stem cells are not modified in any way, simply isolated and sprayed onto burn wounds.

This skin gun seems to hold much potential for healing burn wounds. While still an experimental treatment, the President and CEO of RenovaCare, Thomas Bold, says "We've seen already a couple dozen patients, and we're very happy about the results." See some results of this treatment for yourself, by watching the video at the link below.

Link to watch the video and learn more:
http://www.cnn.com/2016/12/07/health/skingun-burn-care-technologies/

Myostatin Mutations

Many people strive to be stronger. There are even those who spend hours working out daily and eat high-protein diets to sustain their muscle growth. When we see someone that is completely ripped, we may think something along the lines of "Do they even have time for anything else?" While muscle growth does typically require much effort, if genes involved in muscle growth are mutated in a specific way, then muscles can be altered without a shred of intentional effort.

       Such is the case in Belgian Blue cattle (image below). These cattle have been selectively bred for many years since muscle mass in cattle often means more meat and money for breeders. For a long time, the more muscular bulls and cows were chosen for breeding, and this resulted in more muscular offspring. What breeders didn't necessarily understand, was that they were selecting mutations in the myostatin gene. This gene codes for the protein myostatin which inhibits muscle development. The mutated, shorter form of myostatin doesn't function properly, which results in more rapid muscle growth. This creates "double-muscled" offspring that, instead of having the normal amount of muscle fibers at birth, actually have twice as many muscle fibers. The myostatin mutation is considered a permanent muscle mutation within this cattle breed.

But myostatin has the same muscle-inhibiting function in other mammals. Mutations of myostatin have even been found in humans. Several cases of children born with these mutations have been documented, but have only recently been understood (image of boy with a myostatin mutation below). Additionally, myostatin mutations have been induced in mice to create "mighty mice" by Se-Jin Lee and colleagues at Johns Hopkins. Below, there is an image of a normal, wild-type mouse that lacks any myostatin mutation and a mouse with mutated myostatin. You can clearly see that the mutated mouse has much more muscle mass than the normal mouse. The discovery of myostatin mutations and their effect on increased muscle mass has practical applications. These mutations are currently being studied to potentially help people with muscular dystrophies (conditions with weakening muscles).

Link to primary article about Myostatin mutation:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC24998/

Can you Ear me now?

Doctors in China are growing a new right ear for a man who lost his in a car accident. Not in a petri dish in a lab, but on the man's own arm! Dr. Guo Shuzhong, a reconstructive surgery specialist, is leading a team of doctors in a 3-part plan. In the first phase, the skin was expanded on the patient's arm using injections of water. In the second phase, some of the patient's own cartilage, shaped into the form of an ear, was placed into the arm to grow. In the third and final phase, the doctors plan to transplant the new ear onto the patient's head.

This isn't the first case of ears being grown on arms. An Australian artist by the name of Stelarc elected to grow a third ear on his arm for the sake of art. Although the ear isn't yet used for hearing, he plans to pursue further operations to install a Wi-Fi enabled microphone so that people can "tune in" to his station and listen to whatever his ear is hearing (image of Stelarc and his ear below).

Link to recent reconstructive ear story:
http://www.foxnews.com/health/2016/11/10/doctors-grow-man-new-ear-on-arm.html

Link to video of this reconstructive process:
http://www.wsj.com/video/chinese-doctors-grow-new-ear-on-man-arm/37480AB0-9361-4354-B75E-6C7CB273FED2.html

Link to 2015 Stelarc story:
http://www.cnn.com/2015/08/13/arts/stelarc-ear-arm-art/

Thanksgiving, Wine, and Bluebirds

Thanksgiving has come and gone, and we all likely feasted on turkey or ham, stuffing, potatoes, pumpkin pie...and maybe a glass or four of wine. Since wine is so often enjoyed, and wine-making can be very profitable, many researchers out there are studying what makes wine better. Still, before grapes are even collected, they are obviously grown in vineyards. A recent study looked into how vineyards may benefit from other animals in the environment: bluebirds.

Unfortunately, trees that house bluebirds are frequently cut down to make room for expanding vineyards. This study examined whether putting up birdhouses (for the bluebirds to live in) is beneficial to vineyard owners. To do this, they collected fecal samples from many bluebirds in Napa Valley, and analyzed the poop for DNA fragments (a process they called "molecular scatology"). The researchers used readily available databases to match the DNA fragments they found in the bluebird poop to the DNA of known species. In other words, they figured out what the birds had been eating.

When they compiled their findings, the researchers saw that bluebirds generally eat a lot of herbivorous insects (mosquitoes and other species), and only about 3% of their diets are from predatory or useful insects. From the standpoint of winemakers, this is a really good thing! It means that the bluebirds are consuming the insects that could potentially eat or damage their crops. Also, we didn't know that bluebirds eat mosquitoes (insects that are not just annoying, but also can spread harmful viruses). These findings might encourage winemakers to install more birdhouses, which would benefit the birds, the winemakers, and all of us happy consumers of wine.

Check out this link to learn more:
http://www.popsci.com/bluebird-poop-proves-their-value-to-california-vineyards

We Are What We Eat

A very recent study by scientists at the University of Oxford reveals an interesting link between organisms and what they eat. To build DNA, an organism must have access to all the right components. If an organism has a restricted diet, and has limited DNA components, then it would make sense that their DNA would be different from an organism that did not have this limited diet. This was the scientists' hypothesis: the composition of food could alter their DNA.

To test their hypothesis, they examined similar groups of parasites that shared a common ancestor but have evolved to eat different food. The researchers developed mathematical models to make DNA comparisons and found that parasites with low-nitrogen diets had DNA sequences composed of less nitrogen than parasites that ate nitrogen-rich food. Interestingly, they also found that it's possible to predict diets of related organisms by comparing their DNA. The authors believe their findings shed light on the mystery of how two highly related organisms can have very different DNA, and also recognize that there are many other factors that influence the DNA of organisms.

Link to review article: https://www.sciencedaily.com/releases/2016/11/161115111720.htm

Primary Reference: 

1. Emily A. Seward, Steven Kelly. Dietary nitrogen alters codon bias and genome composition in parasitic microorganisms. Genome Biology, 2016; 17 (1) DOI: 10.1186/s13059-016-1087-9

Squirrels with Leprosy

Leprosy is a historical disease that has been around for thousands of years. In medieval England, leprosy was a fact of life, with hundreds of care facilities on the outskirts of towns. Although not life-threatening, leprosy is caused by a bacterial infection and visibly damages skin and nerves, making the disease one of deformity rather than death. While rates of leprosy in humans drastically decreased long ago, leprosy has recently been discovered in squirrels in the UK.

Bishop instructing clerics that have leprosy

A paper published on the 10th announced that two strains of leprosy-causing bacteria have been discovered in a red squirrel population in the UK. Previously, only humans and armadillos had been found susceptible to leprosy. One strain found in the squirrels is highly related to the strain that infected people in medieval Europe. Scientists aren't exactly sure how the squirrels became infected with leprosy, but they believe the disease may have been passed between squirrels and humans. This is similar to the few cases of leprosy in the southern U.S. that were transmitted to humans from armadillos. Yet, there is no serious need to fear becoming infected with leprosy, since the disease is now very treatable with antibiotics, and the bacterial strains carrying the disease are quite fragile and often die within a few hours after removal from their hosts.

Squirrel showing signs of leprosy on its ear and muzzle

Link to review article: http://www.popsci.com/medieval-strain-leprosy-found-in-red-squirrels-in-uk

Does This Tickle?

Aristotle was puzzled by an interesting fact: Why can't humans tickle themselves? We have all experienced being tickled at some point or other, but do we understand how tickling works? This is something that some scientists are striving to understand, but not only because of simple curiosity. One tell-tale sign of Schizophrenia is the ability to tickle oneself. Also, tickling is linked to our ability to laugh, play, and simply feel good, so researching how tickling works adds to our understanding of positive and negative emotions, even depression.

Neuroscientists performed an experiment in which they tickled rats and studied their physical and neural responses. They found that the rats learned to enjoy the tickling and even came to think of the hand doing the tickling as their "playmate." The rats displayed a universal expression of positive emotion called "joy jumps" that are also seen in human children, dogs, foxes, and guinea pigs (to name just a few). To record neural activity, the scientists inserted electrodes into the somatosensory cortex of the rats. Cells in this area of the brain increased firing while the rats were being tickled, but also after the tickling as the rats chased the hand and "giggled." Interestingly, when the researchers applied an electrical current to these same cells, this stimulated the rats to behave as if they were being tickled (giggling and jumping playfully). This is important evidence that shows these cells are responsible for ticklishness.

As you might already know from experience, ticklishness also depends on mood. If we are in good moods we are more likely to laugh when being tickled and when we are in bad moods we are likely to complain when we are tickled. They also tested this on the rats by exposing nocturnal rats to a bright light (making them unhappy or anxious) and observing their responses to being tickled. They found the rats were much less ticklish and did not display the signs of playfulness that they did in the previous experiment. Also, the cells in that somatosensory cortex were suppressed, adding evidence to the finding that these cells are required for the typical tickle response. The researchers also came to the conclusion that our brains must form hard-wired connections early in life for the tickling sensation to be learned, and even potentially enjoyed. If we don't experience tickling when we are young, then we are much less likely to enjoy tickling later in life.

Link to video and review of this research:
http://www.sciencemag.org/news/2016/11/watch-these-ticklish-rats-laugh-and-jump-joy

Brain-Spinal Interface: Bypassing Injuries

An international group of scientists collaborated to develop a brain-spinal interface that is able to bypass spinal cord injuries to restore intentional walking in a paralyzed leg. Typically, neurons in the brain work with the spinal cord in order to make walking possible. Electrical signals originating in the motor cortex of the brain travel down to the lower spinal cord where they activate motor neurons that signal muscles to extend and flex the leg. An injury in the spine can cut off this communication. To help regain this communication, a pill-sized brain chip was made and put in the brains of paralyzed rhesus monkeys where it recorded signals from the motor cortex. These signals were then sent to a computer for decoding. The decoded neural messages were wirelessly sent to an electrical spinal stimulator implanted below the area of injury. This signaled the spinal nerves to perform locomotion and the paralyzed monkeys were able to walk on a treadmill. The many scientists who played a part in developing this brain-spinal interface are very excited by this progress but stress the importance of further research before this type of interface can be used in humans.

Review: https://www.sciencedaily.com/releases/2016/11/161109133133.htm

Primary study: http://www.nature.com/nature/journal/v539/n7628/full/nature20118.html

Growing Hearts for Transplants

Many people are on waiting lists for organ transplants. Unfortunately, many people will not receive the organ they desperately need. For example, there are about 4,000 people in the U.S. awaiting heart transplants and only 2,500 of these will receive a new heart within a year. Additionally, a serious problem with transplants is the possibility of organ rejection (when the body's immune system doesn't recognize the new organ and instead fights the foreign cells).

Now imagine if human hearts could actually be grown, not taken from an organ donor, but actually grown by scientists in a lab. This would potentially provide many sick patients with the heart they need to survive and wouldn't otherwise receive. This concept is not science fiction. Scientists have been working on growing organs (ears, lungs, bladders, windpipes etc.) that are specifically designed for their recipient. The process works by using a scaffold of the particular organ (like a template) and seeding the scaffold with stem cells derived from the patient (building upon the template). This means that the organ will not be rejected by the patient's immune system since it was formed from his or her own cells. 

Recently, scientists from Massachusetts General Hospital and Harvard Medical School have grown full-sized, beating human hearts using stem cells. First, they take skin cells from the adult patient and genetically reprogram them to make them into stem cells (called Induced Pluripotent Stem Cells or IPS cells). Then, a donor heart that is deemed unfit for transplantation is washed with a detergent and many of its cells are stripped away, leaving the heart scaffold. At this point, the patient's reprogrammed stem cells are applied to the scaffold where they take hold, grow, and divide. After about 2 weeks in a nutrient-rich solution, the heart looks like a developing human heart and even beats when given an electrical signal! 

While not quite ready for transplantation into patients, this research provides much hope to those that need a heart transplant. Researchers are now trying to increase the number of IPS cells they can create, as well as speed-up the cell maturation process. 

http://www.popsci.com/scientists-grow-transplantable-hearts-with-stem-cells

Images: Stripped human heart (left) and heart grown using a scaffold and IPS cells (right)

Animal Cloning

Let's talk about the cloning of animals. For many of us, the first thing that often comes to mind is the famously cloned sheep named Dolly. Cloned by Scottish scientists in 1996, Dolly was created by a process called somatic cell nuclear transfer which basically means that a cell nucleus from an adult sheep  (which contains the genetic information) was placed inside an unfertilized egg that had previously had its original nucleus removed. The developing blastocyst is then placed in a surrogate mother where the rest of development occurs. Not without a sense of humor, Dolly's creators named her after Dolly Parton (for two large reasons) since she was cloned using a mammary gland cell. One important fact about Dolly is that she was able to successfully reproduce and during her life she gave birth to 6 lambs (image below shows Dolly with her first lamb "Bonnie"). Ultimately, Dolly developed a progressive lung disease and arthritis that led to her being euthanized in 2003.

Because Dolly the cloned sheep was created 20 years ago, it isn't surprising that other animals have been cloned since her time. In fact, many other large mammals have been cloned including pigs, goats, horses, cows and bulls. Companies can even select prize-winning bulls and use them in the cloning process to create many other valuable bulls. Meat products from cloned animals have regularly been sold in the United States since 2008 when the FDA decided that cloned meat from these animals is just as safe for consumption as food from traditionally-bred animals.

On a different note, many of us develop strong bonds with our pets. Well, several hundred cloned pets (mostly dogs and cats) have been created throughout the world. The price tag is high and ranges from about $30,000 to about $160,000 depending on type of animal and which company you choose to go with. Still, if you have the desire and funding, you can re-create your current pet many times over. Below is an image of a couple who paid $155,000 to clone their pet dog. The wife holds a picture of their deceased dog (Sir Lancelot) while the husband cuddles the new puppy fittingly named Lancelot Encore.