Mallory+S.

**Wiki post #3, June 7th 2014, The nervous System** **How are Memories Made?**



====Neuroscientists have used experiments with rats to confirm a theory of how memories are made and stored in our brains. By controlling rats' brain cells that they had genetically engineered to respond to light, they were able to create fearful memories of events that never happened and then to erase those memories again. ====

====It was in the 1960’s and 1970’s that researches in Norway noticed a reoccurring habit of the brain cells. They would repeatedly deliver a burst of electricity to a neuron in an area of the brain known as the hippocampus. This seemed to increase the cells’ ability to “talk” through the synapses to a neighboring neurons. This repeated neuron firing was called, long-term potentiation (LTP), and neuroscientists believed it was the physical basis of memory. The suspected that the hippocampus was essential for long-term memory. ====

====By continuing research around LTP and its role in memory, neuroscientists found that synapses are strengthened whenever rodents are put into new areas- recording it in their memory. However, by blocking the LTP with drugs or mutations in specific genes, they found it to impair memories in mice. Until now, none of these experiments could show indefinitely that LTP was the basis of memory. ====



====At the University of California, Robert Malinow and his team turned to a technique that uses light to activate neurons. The research began by inserting a gene that produces a light-sensitive protein into a virus and then injecting the virus into rats’ brain cells. Once the gene had been translated into protein, ====

====Next, researches began experiments which began by playing a specific tone to a rat and then quickly following it with an electric shock. The rats soon learned that the tone was associated with the shock and would get scared and freeze whenever they would hear the tone. By using optogenetics, Malinow’s team found that they could create the same kind of fearful memory. They do this by delivering light to the neurons that connect the brain region involved in processing sound with one that handle fear, and then shocking the rats. ====

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*(Because I had no clue what it was)* Optogenetics: “The combination of genetics and optics to control well-defined events within specific cells of living tissue. It includes the discovery and insertion into cells of genes that confer light responsiveness; it also includes the associated technologies for delivering light deep into organisms as complex as freely moving mammals, for targeting light-sensitivity to cells of interest, and for assessing specific readouts, or effects, of this optical control.” =====

====The synapses of the neurons displayed molecular changed that are a trademark of LTP. After this, to prove that LTp was actually involved in forming the memory, the researches tried to erase the association and then bring it back by re-strengthening the connection using LTP. Amazingly, this was able to be accomplished with light that activated the neurons that stored the memory. ====

====By exposing rats to the light sequence, whenever they heard the tone, they were no longer frightened. After removing that memory, they were able to re-implant it by delivering light pulses that are known to create LTP. ====

How Neurons and the memory are connected
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For more reading on the connection between neurons and memory:
Article - http://www.nature.com/news/flashes-of-light-show-how-memories-are-made-1.15330

Society of Neuroscience - http://www.sfn.org/

Journal of Neuroscience - http://www.journals.elsevier.com/neuroscience/

The Human Memory - http://www.human-memory.net/brain_neurons.html

References:

http://www.sfn.org/

http://www.nature.com/news/flashes-of-light-show-how-memories-are-made-1.15330

http://optogenetics.weebly.com/what-is-it.html

http://www.sciencemuseum.org.uk/whoami/findoutmore/yourbrain/whyisyourmemorysoimportant/howdoesyourmemorywork/howdoneuronscreatememories.aspx

=Wiki post #2, ,April 30th 2014 - Evolution= =The Evolution of Dinosaurs into Birds=





**There are many who believe that birds are descendants of dinosaurs.** There is a large dispute between many scientists of whether there are evolutionary relationships between birds and dinosaurs. Although most scientists can see t hat birds are closely related to dinosaurs, the dispute revolves around how they are related.

On one side, birds survived the extinction of most others life forms and have evolved into the birds we know today, saying that birds are dinosaurs. While the other opinion is that birds and dinosaurs have a common ancestor; therefore, birds were never dinosaurs, but they are the closest thing to dinosaurs that we have.

**To be exact**, the similarities that many scientists find are between birds and a group of dinosaurs known as ** theropods. **

**The theropod** (which interestingly means “beast-footed”) is a suborder of bipedal saurischian dinosaurs. Most of these dinosaurs were carnivores and were some of the largest reptiles to ever walk the earth. They first appeared over 230 million years ago during the late Triassic period.

By examining fossils, scientist can trace bird like traits in theropods. For example, the number of openings in the skull are the same in both theropods and birds. In addition, they have similar secondary palate structure, leg and foot structure and proportions, uprights stance, type of reproduction (laying eggs- oviparous), bone structure and in some cases feathers.

**Feathers** are distinct features of birds and although many dinosaurs has feathers their uses vary. For example, Sinosauropetryx were one of the first dinosaurs to have feathers that grew on their head neck and bodies. These feathers provided insulation, but we do not know if they were used for display, camouflage or other functions. One thing we do know is that they were not used to fly. Feathers on the Sinosauropteryx were branched and downy and not asymmetrical like the feathers used for flight.





Many noticed these similarities between birds and dinosaurs, but it was not until **1860** (shortly after the publication of Charles Darwin's influential work " On the Origin of Species By Means of Natural Selection") when a quarry worker in Germany named Karl Häberlein, noticed an unusual fossil. This fossil known as the 'London specimen' was of an Archaeopteryx Lithographica. It was so famous because it was an example of a “transitional form” between two vertebrate groups - traditional reptiles and birds.

Archaeopteryx, is accepted as one of the oldest “birds” that we know of. There have also been more recent findings in reigions of China where to bird-like Unenlagia was found as well as feathered dinosaures such as the Sinosauropteryx that was mentioned earlier.

New discoveries are always being made...
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For more reading on the evolution of dinosaurs into birds go to:
Reading " Did Birds Evolve from the Dinosaurs?" : http://10e.devbio.com/article.php?ch=16&id=161

A simple expalnation: []

The history: []

Reading: http://www.nhm.org/site/research-collections/dinosaur-institute/dinosaurs/birds-late-evolution-dinosaurs = =

References:
http://evolution.berkeley.edu/evolibrary/article/evograms_06

http://www.ucmp.berkeley.edu/diapsids/saurischia/theropoda.html

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Wiki post #1, Feb 28th 2014 - Genetics


 * Pharmacogenomics **



==== **Why is it that people respond to prescribed medications differently?** Some medications seem to work better for some people than others. T he reason this may occur could be discovered in our genes. Although 99.9% of the information in human genes are identical between all humans, the remaining 0.1% of genes present in all human cells are they key to a person’s individuality. Usually these differences do not cause any problems with the development of the body, but they do influence an individual’s vulnerability to certain health problems or how they will react to various treatments, and especially how medications are metabolized. It is said that 20-90% of a persons variation to drug responses are based on genetics. ====

[[image:smithlhhsb122/DNApharma.jpg width="380" height="226" align="right" caption="Possible Reactions to the Same Medication"]]
==== **Pharmacogenomics** is the study of how our genetic variations can determine drug behavior in our body. Scientists, doctors, and the pharmaceutical industry are currently working to adapt medical treatments to suit our genetic differences. With these discoveries, instead of prescribing one medication for a variety of people, personalized medications can be created that will have a better chance of having positive effects on the patients without negative side effects. ====



**Common differe** **nces** in peoples genetic information are often changes to a single letter of the four that make up the **DNA code** (A,T,C,G). For example, the DNA letter ‘C’ might be changed to an ‘A’, changing the message of the gene slightly. These variations are what can impacts someone’s response to medications. With different DNA codes, medication may be broken down at different speeds, effecting their ability to function properly. Because genes are passed on from parents, DNA codes are often very similar when following a persons ancestry.


 * Here is a video made by Mayo Clinic about pharmacogenomics and what they are currently doing:**

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An example of how DNA can effect peoples reaction to medications is the reaction of peoples of European or UK ancestry to ACE inhibitors (angiotensin converting enzyme inhibitors). ACE inhibitors are drugs used to improve high blood pressure and sometimes heat failure. Researchers found that people of European or UK ancestry that used ACE inhibitors were more likely to have improved symptoms and survival than people form an African-American ancestry.

With more knowledge around the topic of pharmacogenomics there will be many advantages. Being able to prescribe medications based on a patient’s genetic profile will decrease the possibility of an adverse reaction that may commonly occur when doctors must use trial and error methods when prescribing medication. We will also be able to develop drugs that maximize their therapeutic effects and decrease the damage on nearby healthy cells. ** For more reading and information on pharmacogenomic check out the following: ** How drugs used to be developed, are developed today and how they could be developed on the future: http://learn.genetics.utah.edu/content/pharma/development/ What is pharmacogenomics? http://ghr.nlm.nih.gov/handbook/genomicresearch/pharmacogenomics ====The Pharmacogenomics Journal - rapid publication of original research on basic pharmacogenomics: ==== http://www.nature.com/tpj/index.html

You script - pharmacogenetic testing :
http://youscript.com/healthcare-professionals/what-is-youscript/pharmacogenetic-testing/

Refferences:

http://www.clinchem.org/content/50/9/1526.full [] http://www.camh.ca/en/research/research_areas/clinical_translational_labs/Pages/Pharmacogenetics-Program.aspx http://www.yourgenome.org/sis/pharm/pg1_bg/pgx01.shtmlhttp://  youscript.com/healthcare-professionals/what-is-youscript/pharmacogenetic-testing/