Think Bomb

Monday, July 31, 2006

Wheat: It's What's for Breakfast

Sponge cake. Spaghetti. Coco puffs. French loaf. All of these foods are certainly very distinct from one another (I know I’ve got to be in a particular mood for any one of 'em) yet they are all primarily a product of wheat. How does something so simple and seemingly homogenous as wheat come to make such vastly different foods?

Well, that's why wheat is only seemingly homogenous. Each strain of wheat has its own unique characteristics, much like the different breeds of dog. There are hundreds of kinds of wheat and wheat breeders are constantly trying to find a better wheat for the types of foods they're interested in producing.

It can be frustrating to know which strains to breed and running a trial all the way through to the market is quite costly when you consider the amount of energy gone into milling and processing. This is where my friend, food scientist Kameron Pecka, comes in. Kam works for the USDA Western Wheat Quality lab in Pullman, WA, where he, to put it bluntly, measures wheat hardness.

Measuring "hardness" is more complicated than it seems. First, Kameron must photograph the rectangularized wheat endosperm and take its dimensions. Then, using a TA-XT2 (photograph at right), Kam measures the stress and stain on the wheat. Next comes the number crunching: Kam uses graphs and equations involving the stress and stain to determine Young’s modulus, which indicates the elasticity of the wheat, and the total failure energy and force. All these figures come together to give an indication of hardness.

"My work is more physics than biology," says Kam, who’s found himself faced with a calculator most days.

Putting Kam through all these calculations is not just an instrument of undergrad torture, though. Hardness is an indicator of many things that are extremely useful to wheat breeders. The texture of the wheat gives clues about its nutritional content, how much work must be put into milling, and what sort of foods it should be used for. Soft wheat typically goes into cookies, hard into certain breads, and durum is used to make pasta.

Currently Kam is busily working on a paper that will hopefully begin peer review in October. He’s excited by the possibility of being an undergraduate co-author.

As for "cracking wheat all day," Kam says his job is "monotonous, yet frighteningly satisfying."

The Drink!
: Kam is enjoying a Hefeweizen, a German wheat beer which has not had the yeast filtered out. It’s extremely tasty when served with a slice of lemon.

Image sources:

Friday, July 28, 2006

Mg in Me?

I donno, looks kinda dangerous

Dr. Pall’s research on the NO/ONOO cycle has certainly gotten me interested in antioxidants, especially magnesium which was mentioned in his book. Although our primary interest tonight is its antioxidant qualities, magnesium has many functions in the body. According to the office of dietary supplements, "magnesium is needed for more than 300 biochemical reactions." Many people have heard of magnesium’s important role in keeping bones strong, but it also plays a part in maintaining heart rhythm, body temperature, nerve function, and immune health.

An excellent source of magnesium is raw, green vegetables as magnesium is central to each chlorophyll molecule. Chlorophyll are the powerhouse of plants, converting sun light to energy through and electron transport chain. They are what give plants their color as they absorb red light (680 and 700nm wavelengths) and reflect green. Some beans, nuts, fish, and whole grains are also an excellent source. More refined grains (such as in white bread) or cooked vegetables contain less magnesium than they would without processing. Tap water can even be a source of magnesium, if it is so called "hard water," which contains more minerals.

A magnesium meal:
2 tablespoons vegetable oil
Cashews, 1 ounce
1/2 cup spinach
1/2 an onion, sliced
1/2 bell pepper, sliced
1/2 teaspoon salt
1/8 teaspoon black pepper
1/2 can black beans
1 cup brown rice
You can add chicken bouillon to this, too

Boil brown rice in water with 1 tbs olive oil. Add beans when the rice is done and let them cook together with curry and all the seasonings.

Coat bottom of nonstick pan with ½ water and ½ olive oil. Lightly fry oinion, cashews, and green beans. Add the spinach next. Once the vegetables are slightly softened, add them to the brown rice and black beans.


Wednesday, July 26, 2006

The Bleeding Edge of Disease:
"No! Oh No! a New Cycle!"

A few weeks ago I had to take a little break from my experiment for our weekly Research Experience for Undergraduates seminar. Feeling casual and not expecting much, I left my tissues incubating and strolled on down to the mechanical engineering building where the seminars are held. I had no idea that I was about to embark upon a starting new theory, possibly even a new disease paradigm!

There are currently many known causes of disease including infection, genetic disorders, cancer, autoimmune diseases, and poisoning. Still, some illnesses remain unexplained by known etiological mechanisms. Sicknesses such as chronic fatigue syndrome (CFS), multiple chemical sensitivity (MCS), fibromyalgia, and posttraumatic stress disorder (PTSD) appear not to fall into any known category and remain mysteries to the medical community. Their odd set of symptoms and the variety of cases are a puzzle what have continually frustrated doctors, researchers, patients and their families. They do have a few things in common though, besides the fact that they remain unexplained. Many patients experience a "trigger" which initiates their illness, commonly a severe emotional stressor, injury, or infection. They are all chronic illnesses with multiple symptoms. There is also a great deal of overlap in diagnosis of these disorders as they share many qualities, almost all involving some form of fatigue, hyperalgesia (excessive pain), depression, or anxiety. With so much in common, could there be a common cause for these illnesses? Dr. Martin Pall of Washington State University says, "yes!"

At the seminar Dr. Pall exposed his fascinating new theory on the possible cause of these disorders (and maybe others). He proposes a vicious cellular cycle that, once triggered, may continue indefinitely unless measures are taken to moderate it.

Inherent in all our cells is the ability to produce nitric oxide from the action of nitric oxide synthase enzymes. Nitric oxide (NO) is a natural part of the environment of the body and plays important roles as a neurotransmitter and cell signaling molecule. Unfortunately, when stressed, these nitric oxide synthase enzymes can begin to produce excess NO and its oxidant product peroxynitrite (ONOO) leading to a chronic, cyclic increase in the quantities of both chemical products. The up-regulation of nitric oxide and peroxynitrite make up part of the vicious cycle Dr. Pall calls the "No!, Oh no!" cycle after the convenient way the chemical abbreviations for nitric oxide and peroxynitrite (NO/ONOO) can be read.

Aside from NO and ONOO, there are multiple cellular mechanisms involved in the NO/ONOO cycle. Thus far, Dr. Pall suggests 22 mechanisms in the cycle, which, when diagramed, appear more like a mass of arrows than a circle. Among the things feeding from and feeding into the cycle are transcription factors for production of nitric oxide synthase enzymes, inflammatory cytokines, intracellular calcium ion levels, and activity of the NMDA and Vanilloid receptors. For each disorder, human or animal models have been found to have an excess of some or all of the elements of the cycle. Dr. Pall cites a convincing number of studies for each illness, all pointing to one or more of the cellular pathways involved. Below is a figure he sent me, depicting the many cellular pathways of the NO/ONOO cycle:

All together the NO/ONOO cycle has dire effects on the health of cells. Primarily, peroxynitrite is detrimental to the function of mitochondria, the cell’s energy production source. When these important energy organelles are damaged, fatigue, a common symptom of the "unexplained" illnesses, is inevitable. The cycle also results in oxidative damage to cells and the tissue of the affected area is harmed. Another result of the cycle has to do with stimulation of certain neural pathways. Nitric oxide stimulates the nociceptors that initiate the perception of pain and this may explain the common hyperalgesia symptom of these illnesses. NMDA receptors also respond to NO and ONOO as well as contribute to their up-regulation. NMDA receptors are common in the amygdale where their excessive firing can create anxiety.

Now, this all sounds quite alarming, but before you go tossing all of your "miracle blue pills for the middle aged man," or chastising Stephan and John for their work in synthesis of NMDA agonists, remember that nitric oxide does play some important roles in the body too. So if this cycle is possible in us all and can be initiated by such seemingly common stressors like infection and injury, why do some people develop chronic illnesses while others do not? One factor may be the severity of the stressor. More potent, long lasting infections may increase the levels of inflammatory cytokines more than others and therefore better contribute to the cycle. There may be a genetic link that makes some people more susceptible as well. Hormone levels may also play a role. Diet is an especially important factor to look at though as it may have a healing influence on the cycle. Antioxidants will lessen the effects of the NO/ONOO. Magnesium is an antioxidant of key interest as it also lowers NMDA receptor activity. The U.S. is known for some magnesium deficiency, so it's no surprise that the incidence of NO/ONOO cases may be high here.

For each symptom of these puzzling disorders, a possible cause can be traced back to some element of the NO/ONOO cycle. If true, the theory provides a basis for new research into possible cures. I hope to write more on this topic and the fascinating cellular mechanisms involved in future "Feature Wednesday" articles. Dr. Pall has been kind enough to allow me to review a draft of his new book, Explaining "Unexplained Illnesses": Disease Paradigm for Chronic Fatigue Syndrome, Multiple Chemical Sensitivity, Fribromyalgia, Posttraumatic Stress Disorder, Gulf War Syndrome, and Others and I still have a long way to go before it's finished. Although the theory has not yet been accepted I'm excited to be one of the first to read about (and I hope you are now too!). As D. Pall writes in his book,

"At worst, it gives us a testable framework for further 'hypothesis driven experimentation'...At best, it provides the great beam of light to illuminate our way."

Sources: Dr. Martin Pall. Explaining "Unexplained Illnesses": Disease Paradigm for Chronic Fatigue Syndrome, Multiple Chemical Sensitivity, Fribromyalgia, Posttraumatic Stress Disorder, Gulf War Syndrome, and Others. Slated for publication in May 2007

Monday, July 24, 2006

I could go for some EAATs right now…

Between recent research on multiple intelligences and all the controversy over Chinese food and diet soda, glutamate and its receptors are certainly a hot topic. As mentioned previously, glutamate is the most abundant excitatory neurotransmitter in the central nervous system and is also a common amino acid, readily available for the hungry brain. Glutamate has several different receptors, including the fast acting AMPA and NMDA receptors (which also binds aspartate) and the slower metabotropic receptors. NMDA stands for N-methyl d-aspartate and AMPA stands for α-amino-5-hydroxy-3-methyl-4-isoxazole propionic acid, so named for the first synthesized agonists that could produce firing in the neurons containing those receptors.

NMDA's affinity for glutamate declines with age, which may explain why grandma can be a little "slow" at times. Many drug companies are searching for ways to abate this process. There is also such a thing as "too much of a good thing," where over-stimulation of glutamate receptors can be problematic; drug companies are interested in resolving this as well. That's where today's Blue Monday interviewees come in. Chemists John Rudolph and Stephan Smith have been working on synthesis of isoxazole based ligands for use as NMDA and AMPA agonists (activators) and some for use as antagonists (blockers).

Here's John (left) and Stephan (right) looking curiously Watson and Crick as they ponder their chemistry. Working with all these excitatory receptors, John says he's certainly experienced "multiple realms of excitement." The thing that excites him most though is the fact that the ligand research is so new.

"It's something that has really stretched me," says John, "and I like that."

Aside from affecting receptors directly, another goal of theirs is to inhibit the action of excitatory amino acid transporters (EAATs). This may increase the concentration of glutamate at the synapse, similar to how MAO inhibitors work in anti-depressants. EAATs are responsible for transporting glutamate back into and out of glial cells, where it undergoes processing before it is restored to the neuron. The EAAT they're mainly interested in is called XCT, which pushes glutamate out of nearby glial cells. had an awesome depiction of a simplified glutamate synapse which I've included below:

The Drink!:
In honor of these great chemical creations, the drink I'd like to share with you tonight is called a "Chemical Equation," but no stoichiometry is needed! Mix club soda and lemonade with a shot of vodka then add a splash of grenadine and a cherry.


Friday, July 21, 2006

Did you just say good fat?!

Fat. If you ask me, it’s got a bad rap. Sure we all know about the dangers of going overboard on the stuff, everything from clogged arteries to reduced sex appeal, but it also plays some very important roles in the body. This may partially explain why we’ve developed such a love for the stuff over evolutionary time.

Fats are used to form the lipid bilayer of cell walls, as padding against shock for organs, as a buffer against invading disease organisms, and, of course, as energy storage molecules. It is also important to the function of certain signaling molecules in the body. Some vitamins and a few hormones, like estrogen, are fat-soluble, which is why women must maintain a certain weight to continue to menstruate.

Fat certainly plays an exciting role in the brain. The brain is one of the fattiest tissues in the body, second only to fat (adipose tissue) itself! The brain needs all this fat to "cushion" its circuitry. The axons ("sending" end) of neurons are covered with a myelin sheath that acts like insulation on a wire. Neurons that are used most require more myelin to function well. If untreated, problems like malnutrition and anorexia will result in a loss of brain tissue from the lack of myelin.

If you're like most Americans though, you probably get enough fat in your diet. If your BMI is over 18.5, you're likely doing fine, and if it's over 30, you might want to consider some dietary changes to reduce your fat intake. Keep in mind that the BMI is just a rough estimate, so if you're truly concerned about your fat intake it would be best to consult a physician.

Although fats are important, not all fats are the same. For example, trans-fatty acids (such as those found in French fries) are linked to heart disease whereas unsaturated fats (such as those found in olive oil) help your heart health.

Saturated fats are so called because their fatty acid chains are saturated with hydrogen atoms while unsaturated fats have at least one double bond between the carbons in the chain:

For this week's Science of Yum recipe, I'd like to focus on one of the important fat molecules that the body cannot synthesize on its own: omega-3 fatty acid, a polyunsaturated fat. Omega-3 is found in salmon, and have I got the recipe for you:
• 1/4 c packed brown sugar
• 2 Tbsp Dijon mustard
• 1 Tbsp grated fresh or 1 tsp ground ginger
• 4 6-oz salmon fillets, about 1" thick, skinned (in my case, four of the little filets that come in the $.89 packets at Winco)
• 1/2 tsp salt
• 1/2 tsp freshly ground black pepper (in my case, from the shaker)

1. Coat rack of broiler pan with cooking spray. Preheat broiler.

2. In small bowl, whisk sugar, mustard, and ginger. Season both sides of fillets with salt and pepper. Place salmon on broiler rack and brush glaze on top. Broil (6" from heat) 8 to 10 minutes or until fish is lightly browned and opaque.

I served mine with wild rice pilaf, red potatoes, and green beans:

Thank you, Holly and Jen, for helping me to NOT burn the house down during this project!

To find out more about fat, its many functions, and how to get healthier fats in your diet, check here:


Wednesday, July 19, 2006

Field Trip!: Gritman Medical Center

Last week I went on a radiology field trip to check out some of the fascinating machines we have at Gritman Medical Center here in Moscow.

One of the radiologists there, Jody Polly, provided the tour.

She was extremely helpful and sweet. She’s especially excited about the new technology they have for doing mammograms and detecting osteoporoses. Being the ever curious aspiring neurologist though, I asked her to take me to see the CT scanner and MRI first.

Here’s Dr. Rizenhour sitting at the computer deck for the computerized tomography (CT) scanner.

CT scanners are very similar to traditional x-rays in that they make use of electromagnetic radiation to produce images of the inside of the body. An internal "shadow" is projected by the differences in how much X-ray can pass through each tissue type. Rather than use a photographic plate to collect the X-rays though, the CT scanner detects the X-rays electronically.

The CT machine looks a bit like a big, delicious doughnut. The patient must lie on a platform which moves through the hole as it produces images of the body. The X-ray tube and detectors are positioned in the doughnut and can circle the body as it moves through the machine.

The CT scanner operates at 16 slices per second. These visual "slices" of the body can then be put together by the computer to produce a very detailed image of the area of interest.

Next I toured the magnetic resonance imaging (MRI) facilities. Here is a picture of the MRI computer deck. Of course, I was not allowed to go into the MRI chamber as it was in use.

There I spoke with Milt (yes, just Milt, even his nametag says "Milt") about their MRI.

"People are often scared when they come in here," he said, "They think the machine is going to suck up all their jewelry, but I just tell them it only takes the precious gems."

Metals can actually become projectiles in the presence of such a strong magnet (1.5 teslas at Gritman), so patients are required to wear a hospital gown.

"With that in mind, can you tell me what MRI stands for?" he says smiling at me.

"Magnetic Resonance Imaging?" I say.

"Nope." He smiles again, "'Milt's Retirement Investment.'"

Aside from joshing patients, Milt knows all about MRIs and told me a few things (most of which I had to re-look up by today).

Basically, an MRI works by detecting the presence of hydrogen atoms (mainly those found in water) in relation to the magnetic field produced by the huge MRI magnet. Hydrogen atoms are easily detected because they have a single proton and a large magnetic momentum.

The nucleus of each atom spins (processes) on an arbitrary axis and when exposed to the magnetic field of the MRI, the spin of the hydrogen atoms will line up in the direction of the magnetic field. If a patient is lying on their back, for example, some of the hydrogen protons will be aligned toward their feet and some toward their head.

Because they can either align up or down with the magnetic field, many of the hydrogen’s spins will cancel each other out. Since there are so many hydrogen atoms in the body though (billions!) there are still plenty of un-canceled signals available for the MRI machine to detect.

To detect these newly aligned hydrogen protons, a coil in the MRI emits a radio frequency (RF) pulse that causes those hydrogen atoms that have not been canceled by their oppositely aligned comrades to absorb the energy required to make them spin with the magnetic field. These atoms begin to spin in a new direction with the emitted RF pulse.

When the RF pulse is turned off, the hydrogen protons can start realigning themselves with the magnetic field and release their newly stored energy. This is the special moment when they emit a signal that the coil can pick up and interpret. They also release heat energy at this time.

"It will warm you up a bit," says Milt, "It really depends on what we're imaging. A knee will be barely be noticeable, but a full torso exam might get you sweating."

The signal from these protons can be interpreted by the computer with use of Fourier transform (there's that word again) to create an image the radiologist can understand.

Each tissue responds to the field in different ways according to its hydrogen content, so you get a very amazingly accurate view of the inside of the body without harmful side effects. It really is an amazing machine!

Here is an animation of MRI slices I collected from wikipedia:


Monday, July 17, 2006

Scene Gist

Computers are able to perform more human-like function all the time as technology improves. Although I think (or is it hope?) Chobits and Blade-Runner are a long way off; surprising new technologies continue to appear with great frequency.

For this week's Blue Monday, I decided to delve into the computer world to interview Geoff Basore and Zach Maier on their biologically inspired computer research. Unfortunately, they were not yet of age so my preferred “scientific” atmosphere of the local Garden Lounge was out of the question, but I did catch the boys on lunch for a photo opportunity:

Geoff (left) and Zach (right) have been working on a program that can identify a scene in milliseconds. The idea for this program was drawn from the human visual system, which can get the "gist" of a scene in a tenth of a second. For example, when flashed a picture of a beach, forest, or portrait a person can usually give the image a category even if it was only displayed for 1/10th of a second (although rapid succession of images greatly increases error).

The program they are working on will classify entire images using color channel values as well as Fourier transforms, which detect the frequencies in a scene giving the program insight on the orientation and diversity in the image.

"Other aspects we hope to explore include contours, shapes, and textures," explains Geoff, who is looking into broadening the abilities of the program.

The program even derives some of its training techniques from biological systems. Particles in the system act like swarms of bees, moving toward better solution to identify a scene. The particles are trained in teams and are randomly swapped at points in training, like chromosomes are swapped during gamete formation and regrouped at fertilization.

"We're not modeling biology," says Zach, "rather, we draw inspiration from it."

With biology as their muse, Zach and Geoff already have their system running at 30% accuracy after only a month and a half on the project.

Geoff is looking forward to the military application of scene gist. Of course, the first thought that came to my mind when they explained this new technology to me was how much better google image search could be with "scene gist" turned on. No more bountiful bosoms or pop stars coming up when I'm trying to search for an image to include with my research (or better yet for my precious blog!). As far as Zach is concerned though, the applications are "pretty much limitless."

The Drink: Even though they're not yet of age, Zach and Geoff wanted to feature pina colada as their drink (the guys will have to have theirs sans rum).
1/3 rum 1/3 coconut milk and 1/3 crushed pineapples

Friday, July 14, 2006

The Dark Side of the Potato

Since I live in the great "potato state" of Idaho, I think for this week's science of yum I'd like to head in the tuber direction. Henry Spalding first planted potatoes in Idaho in 1837 and we've been known for them ever since (although I've more commonly found Washington potatoes in local markets, due to the trucking lobbies that keep foods hopping borders). Now, try not to confuse us with Iowa, the land o' corn. Although corn goes rather well with potatoes, Idaho is not a Midwestern state. Rather, it's just one state inland from the west coast, cozied on up to Washington and Oregon to the West and Montana and Wyoming to the East.

Most of the state looks like this:

Although where I come from it looks more like this:

For as bland and boring as potatoes seem, it's only a guise; they are actually natural born killers. As a member of the nightshade family, they certainly have a shady history. The Irish potato famine of the 1840s caused many deaths, partially due to the scarcity of the major food staple after an outbreak of potato blight, but also due to the toxicity of the remaining potatoes. With little other option, people were opting to eat potatoes which had begun to produce the toxins which give nightshades their reputation: solanine and chaconine. Solanine and chaconine are glycoalkaloids, toxic compounds that cause dizziness, diarrhea, and, if consumed in high enough doses, death in humans. The small portion found in "good" potatoes has little to no effect. It's easy to tell, too, when a potato has turned into a bad tuber. They begin to green under the skin and some sprouting may be seen. If that isn't enough of a turn off, the bitter flavor is a good clue that it's time to toss the potato.

How to keep potatoes from going bad:
- store in dry, dark place
- avoid bruising or cutting
- don't let them wait too long before you eat them
- bake at high temperatures to partially destroy the toxic compounds

Oddly enough, glycoalkaloids are currently being researched for their anticarcinogenic qualities. Glycoalkaloids, when obtained through processing of common potatoes, seem to act to reduce cancerous cell growth. Now, don't go ahead and start mixing a little in with your meals (can you say Qin Shihuangdi?), as studies are still underway for finding safe ways to utilize the compound. They already exist in some skin creams shown to reduce the presence of skin caner.

Cham and Meares. Cancer Letters. "Glycoalkaloids from Solanum sodomaeum are effective in the treatment of skin cancers in man." Aug 1987
Friedman, Lee, and Kim. Journal of Agricultural Food Chemistry. "Anticarcinogenic effects of glycoalkaloids from potatoes against human cervical, liver, lymphoma, and stomach cancer cells." Oct 2005


Wednesday, July 12, 2006

The Glutamate Project

One of the major challenges facing public school teachers is adjusting for the variability in student intellectual capabilities. Inter-individual variation results in a range of intelligence quotients between students but even more challenging is accommodating the intra-individual differences. Each student varies in their own unique abilities, some being stronger in one subject and less so in another. Strengths should be encouraged, as these are what keep children interested in school, but weaknesses still need attention until proficiency is reached.

As an "educator of educators," Terry Armstrong is all too familiar with this problem. He spoke for a research seminar I attended last week and proposes a few different reasons for the intellectual gaps. One is the variation in developmental ages of children; just because two children are the same age does not mean that they are at the same stage of development. Another difference, one that Dr. Armstrong is especially interested in, is the variation in Gardner's seven intelligences. Dr. Armstrong suggests that each of the intelligences; verbal, mathematical, visual/special, kinesthetic, inter- and intra-personal, and naturalist abilities, corresponds to a cortical region in the brain. He believes that the reason for these strengths may be the percentage of glutamate receptors corresponding to each cortical region. He is curious to see if, in those regions that are stronger in some individuals than others, a higher percentage of glutamate receptors may be found.

Glutamate is the most common excitatory neurotransmitter in the cerebral cortex. It has five different receptor types; NMDA, AMPA, kainite, met1, and met2 binding sites. Dr. Armstrong hopes to begin his project looking at that various glutamate receptors in the verbal/linguistic area, including the superior temporal gyrus (Wernicke's area) and the opecular and triangular inferior frontal gyrus (Broca's area). In donated brains with that have been found to be left hemisphere dominant (as determined by the size of the planum temporal), the percentage and types of glutamate receptors in the left will be compared to those in the right. If the study shows that there is a greater density of glutamate receptors in the dominate sides of the brain, it might show that glutamate receptors are an important feature in language skills.

If glutamate receptor density does seem to be a factor in language abilities, Dr. Armstrong hopes to eventually move forward to investigate all regions of the brain that may correspond to various intelligences.

As an ultimate goal, Dr. Armstrong hopes that a better understanding of the human brain will lead to better teaching techniques in the future. He'd like to see a curriculum more focused on multiple intelligences, with more class variety for the varying minds of students.

My thoughts:
This project may answer some interesting questions. I've read about the effects of different neurotransmitters but it is less common to look at the ratios of specific receptors for one neurotransmitter. I'd be interested to see if there are regions with more or less of each type of glutamate receptor. If this is so, another interesting project may be to see if a sort of topographic map of receptor density could be made, depicting the receptor layout of the brain.

As for the educational possibilities, I am in agreement with Terry that high school should be set up a bit more like college with your pick of courses in the later, junior/senior years. I do think it is essential though, that students can show proficiency in math and language as well as a basic understanding of science first.

Monday, July 10, 2006

The Socialization and Genetic Expression of Aggression in Danio Rerio (zebrafish)

This Blue Monday I spoke with Holly Paddock from Dr. Barrie Robison’s behavioral genetics laboratory. She is studying socialization effects on zebrafish aggression.

For the socialization aspect of the experiment, zebrafish that have been determined to be non aggressive are placed in tanks next to aggressive fish.

"We put the aggressive fish with the non-aggressive to see if the non aggressive will change," explains Holly.

The zebrafish are determined to be aggressive or not by their genetic strain (tm1) and also by observation of their behavior through mirror tests and a dyad test.

"A dyad test is where you put two fish together in a tank and it's like, 'round one, fight!'"

After the socialization aspects of the experiment are determined, Holly hopes to move on to explore gene expression.

"We can get two papers out of this one," says Holly, one on the behavioral aspects of the research and one on the genetics.

Holly hopes to see a change in genetic expression of the non-aggressive strain after socialization makes them more aggressive, if they do show increased aggression.

When I asked Holly how she's going to measure their genetic expression, she explained that they'd be using microarrays, a fascinating new technology in the field of genetic research. A microarray allows one to visualize thousands of genes at once by creating a gene chip. Probes of the genetic material are attached to the chip creating patterns of small dots, each dot corresponding to a probe. Here is an image sample of four microarrays from research on halobacteria (unfortunately, little microarray data exists for zebrafish at this point):

"I'm gonna have to kill the fish to retrieve the genetic material," says Holly, "but I figure it's ok, seems how all the fish I've ever tried to keep as pets have died anyway."

The Drink!:
Holly is drinking a Vibrator, which includes orange and raspberry vodka (1/3) mixed into orange and cranberry juice (2/3).

Image source: