New drug makes tumors glow pink

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5-Aminolevulinic Acid(5-ALA) is now being used in terms of brain tumors. When the drug comes in contact with tumor cells, it causes them to glow a hot pink. This new drug has many advantages. Doctors can now tell the difference between healthy tissue and the tumor cells more easily. This allows the tumor to have a more defined edge so when treatment is decided upon the tumor can be removed more clearly. The drug is administered by mouth just before the patient is to go into surgery. With more people being willing to try 5-ALA I think this drug will be beneficial.

Holy Holoprosencephaly!

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Holoprosencephaly (HPE) has a range of disorders from cycloptic eye to cleft palate. There are many genetic and environmental influences in the development of HPE. The sonic hedgehog (Shh) pathway has been deeply explored and has relation so HPE. The regulation of Shh and other genes involved are important for proper mid line separation. This separation is what allows two eyes to develop. When Shh is not produced, there is no mid line separation and cyclopia develops, but when Shh has reduced production there is some mid line separation. The partail mid line separation causes the eye to be not spaced correctly and be close together resulting in hypotelorism. Other factors such as prechordal plate (PCP) axial midline, and Six 3 are also needed for proper mid line separation. PCP is a source of Shh ligans, when PCP is surgically removed cyclopia forms. The same goes for loss of axial mid line. Organisms lacking Six3 cause WNTs to not be inhibited this causes the anterior structures to disappear resulting in atelencephaly.This is described in the illustration below.
It is obvious that there are many ways that proper mid line separation can be disrupted and that a multitude of genes act together to prevent HPE. HPE is not a common human disease, which makes it difficult to research and when HPE is present in other organisms, such as mice, frogs and fish, the learning do not always apply to the human population. I believe the key to understand HPE is in the Shh pathway and the different molecules that are effects and act on that pathway.

Craving Circuit

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I have been doing some interesting reading on the craving circuit and how further experiments can lead to the understanding of drug addictions and relapses. So far my reading is limited on the subject but I find it really neat. Recent studies are pointing to the fact that cravings can activate parts of the cerebral cortex and limbic system which is involved in emotion. TMS(transcranial magnetic stimulation) techniques are starting to be used to either stimulate or depress brain activity and that stimulation can increase the cravings for things such as cigarettes. There was no report that reduced stimulation can decrease craving, but knowing the parts of the brain that lead to the craving can be helpful in future studies. The future studies could be used as a way to help drug addicts from slipping into a relapse. TMS treatment for cigarette addiction will help pave the way for future research of the craving circuit.

Neuron see Neuron do

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A few days ago, I read a very interesting paper on mirror neurons and watched a youtube video barbie doll illusion. After watching the video and reading the article I was intrigued as to how we seem to copy the other people during a virtual simulation. The article was about mirror neurons. Mirror neurons are neurons that fire when we act and when the same act is observed by another. The article focus on how these mirror neurons acted when a person under virtual stimulation was placed in different social events. When the subject was simply observing the act of others throwing a ball there was little "neuron fire" as to say, but when the subject was watching the people throw a ball and randomly had the ball thrown towards their screen(as if they were participating) there were firing of the neurons. This study provided that there is social relevance when considering the mirror neuron system. It also helps provided a link between the social complex observations such as empathy. I thought this article was very interesting and the first thing that came to find was monkey see money do. Except in this case were talking about neurons.


The Dorsal Neural Tube: Cell Fate Decicision

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Today in class we reviewed a paper about the neural tube, and the fates of the cells that are involved. The paper was a review paper and was suggesting that the spatial and temporal information in the dorsal neural tube determines the segregation and derivatives of the neural crest tubes. There is a detailed figure in the paper(Fig 1) that shows the migration of the different cells of the neural tube, and the types of tissues they end up being incorporated in. They also have a figure about gene expression in the neural tube, and that these genes are turned off and on during different parts of delamination of the cells. Some genes are turned on early to help set the pattern and some genes are turned on late to set the fates of the cells. Overall the paper was a little difficult to understand since my knowledge of neurbiology is limited to what I've learned in class, but I find it fascinating how there are so many tiny details and all different cell types and genes have to cooperate together to form proper and functional tissue
. doe_neural_stem_cells.pdf

Neural Stem Cells

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This week in class we have been talking about the differentiation among neural cells during development. We read a paper Neural Stem Cells: From Fly to Vertebrates. Now the paper was long and covered a lot of different topic by comparing neural cells of flies to that of vertebrates. There were several questions they wanted to try and answer in this review. I was reading the paper and trying to figure out the answer to each question myself as well, I realized when it comes to neural cells there is still so much we don't know. The development and differentiation of neural cells(vertebrates and flies) is very complex and depends on a variety of extrinsic and intrinsic factors. These factors determine the lineage, proliferation, maintenance, and progeny of the cells. The overall summary of the paper was that there is minimal knowledge on neural stem cells and we only know a small fraction of information. It has become clear that vertebrates and Drosophila share many fundamental mechanisms of neurogenisis, validating a comparative approach. doe_neural_stem_cells.pdf

Visual Illusions

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Last week in my neurobiology class we were to read papers by David Eagleman, neurobiologist and author of Incognito: The secret lives of the brain. He also came to our class for a short Q&A. I was intrigued on his paper about visual illusions. His main interest was in flash lag illusion and the wagon wheel effect.
Flash lag illusion: a visual illusion when a flash and moving object appear to be in the same place but are perceived to be displaced. One theory is that your visual cue predicts the trajectory of the moving object(Nijhawan, 1994). Another theory is that your visual system can process moving objects more quickly than flashed objects. This basically means that by the time your brain has processed the flash the moving object has already changed positions(Nijhawan, 1994). Eagleman however proposed that "visual awareness is neither predictive nor on-line, but is instead postdictive, such that the percept attributed to the time of the flash is a function of events that happen in the ~80 msec following the flash."
Wagon Wheel effect: Optical illusion in which a spiked wheel seems to rotate differently from its true direction. A 2004 study(Eagleman) revealed that the incidences of reversed rotation were independent in different parts of the visual field.
Obviously with all research there are more questions to be addressed, but the study of illusions allows for understanding of biological proccess and provides insight in the field of neurobiology.
If you are interested in visual illusions or just find them interesting to look at i suggest you to look at the link below or simply google it. First you don't see it, now you do.

Lets get moving!

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This week in my neurobiology class we read a research article titles How Animals Move: An Integrative View. I found this article particular interesting, simply because the general population views movement as just the extension and relaxation of muscles, but never really thinks of the subject in the view of neural mechanical feedback. The paper goes into explain how different animals move in way that is most beneficial to them and that the movement can be influenced on their habitat. Also, that certain movement can allow for energy recovery. The study was focused on how to determine each individual component within a locomotor system operates, while at the same time studying how they function collectively as an integrated whole. The paper also mention 4 themes.
1) Spatiotemporal dynamics of locomotion are complicated but understandable on the basis of a few principles. 2) performance of animals in natural habitats reflects trade-off between different ecological important aspects of behavior and is affected by the physical properties of the environment. 3) control of locomotion is not linear, but organized. 4) muscles perform many different functions in locomotion.
So lets compare walking and running. When walking the center mass is much like a pendulum, at mid stance mass is its highest. Running is like that of a spring, compressing and recoiling. A great example to talk about how habitats effect movement is that of a 2 different jellyfish. A bullet shaped jellyfish uses jet propulsion, but vortices produced by a disk jellyfish are more advantangeous for its body shape. Now we can see how things works as a whole and we see that control systems are closely coupled. Both neural and mechanical pathways is integrated with guidance from eyes, ears, ect.. Example central nervous system generates motor commands that activate the musculoskeletal system of the animal, that in turn acts on the external environment, that is sensed by multiple modalities and fed back to the central nervous system. This provides evidence that the different system are coupled and can be broken down to look at individually and coupled to be studied as an integrated whole.

Peer Pressure

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I was surfing the web and decided to check out the website to see if there was any interesting news. The title peer pressure? It's hardwired into our brains jumped out at me. I looked up the full article on googlescholar and decided to share the information with everyone else.

The specific interest in mind for the study was to investigate how individuals assess the outcome of their decision in private versus social setting and whether depending on the setting, evaluations of outcomes of risky choices influence later decisions. They hypothesized that in a social environment the participant will be more risky in their decision than in a private setting.Brain activity was determined (using a combination of functional MRI and skin conductance recordings) while participants chose between 2 lotteries. In a private setting the outcome of the unchosen lottery was observed and in a social setting the outcome of a lottery chosen by another person was observed.
The medial prefrontal cortex(associated with social reasoning) had larger activity, during the choice phase, in individuals in a social setting rather than private. Analysis of brain activity and behavior showed that brain activity during choice phase is influenced by outcome-related striatum(associated with rewards) activity and past outcomes in social settings affects later behavior. The results showed that the decision process in a social setting(under peer pressure) is influenced by the interaction of the reward and social reasoning networks and that in a social setting participants engaged in more risky and competitive behavior.

There were many parts of this paper that I didn't understand (even after reading numerous times), and I cant get the MRI photos or any other charts/graphs to show up. So for more understanding on the article I suggesting clicking on the link below.

Want a younger brain?


I was surfing around on the National Geographic website and read an interesting article title and had to read more.
Apparently as you age the prefrontal cortex of the brain also ages causing a decline of maintaining working memories. In younger brains the nerves in this part of the brain are constantly excited to keep memories available.
Scientist trained Rhesus monkeys to play video games which made them use the prefrontal cortex, they used a device to measure the neurons firing. When the neuron firing of the older monkeys was measure it was much lower than that of the younger ones. A drug called Guanfacine was administered and when neural activity was measure again it was higher than before. As studies further, this could be very advantageous for human suffering memory loss from car accidents or just helping the elderly remember tasks.

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