I: a Conversation - Last Neuroblog Post

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I would like to preface this post by saying this is my last post on this site. The semester winding down so I am doing my last post a few days early to clear time before finals. Hope whoever has read this blog has enjoyed it. -Ginger Synapse

I choose to study neuroscience because I have never found anything of equal interest, the complexity alone is enough to make me smile. However, telling people I love to study the brain is gateway into questions which deal little with neurobiology and for that matter neuroscience. People assume because you study the brain you can answer questions regarding their lives in a similar manner to a pastor in a church, which I am not. I try to avoid answering these questions because neuroscience, unlike religion, is difficult to accept and where the results seem to appease it is likely due to a lack of research.

The recently popular question to pose is the classic, who am I? The popularity here can likely be attributed to when David Eagleman gave a lecture earlier in the semester and freewill was put into question or rather he simply stated the truth. The next question, is of course, well if I cannot control what I think, then who am I. A question, which likely should have been resolved in the 8th grade, but college is better than never, I guess. Some recent research put out though seems to put this in a nice way which I was unable to articulate prior. The idea shown here is the brain hold a conversation with itself which creates the illusion of a being. Little more has to be said about who someone is, it answers the question. So, now I just have to deal with the reality that I enjoy to hold conversations with myself about holding conversations with myself.

Short Term Memory and Cortex Activation

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The primary somatosensory cortex is known for having many roles in tactile and haptic memory. That is, this region of the brain is known for its role in touch. The processing of touch is complex and involves a lot sorting and coordination in the midbrain and hindbrain regions. The primary somatosensory cortex's role in this process is mostly processing where signals come from, that is it functions a lot to just initially process signals. However, a recent research study from Italy has put this very basic function into question and instead suggest the primary somatosensory cortex also plays a significant role in short term memory.

This study have the subject put their index finger on a vibrating piece of metal. This piece of metal was set to vibrate pretty heavily. The subject would leave their finger on this piece of metal. The metal would then vibrate for one second. After this a 1.5 second delay was given. Then the vibration was repeated (same intensity and duration). Without interference most people could tell these vibrations were the same. However, when researchers took a magnetic coal which worked to disturb the primary somatosensory cortex and applied it to the region, 300-600 ms after the initial metal vibration, subjects were noticeably less accurate and identifying the metal on their finger was vibrating at the same rate.

I thought this article was interesting and goes into more detail, talking other factors. Read up if you would like.

Drosophila are one of the most studied species in the world, offering a great number of answers to complex questions. While a fly fundamentally different in many ways to a mammal, it has proven useful in the past to study flies first because they are easily examined and then to apply to knowledge gained in those studies to mammals. The visual system of flies-that is everything but the actual eye, which is admitted to be fundamentally very different from vertebrates,-is believed be similar between flies and mammals, especially the of the circuitry connecting the retina to the brain. So a publication was put out talking about fly eye targeting to satisfy the curious.

As it turns out, a fly eye starts the process of neuron targeting by sending axons out of retina into a layer of tissue called the lamina. Some of the axons sent into the lamina form a connection to various cells there, which work to process/detect motion. Another set of cells (although some of them have similar labels to the motion detecting cells) send their axons past the lamina to a layer of tissue called the medulla. The medulla is separated into six regions and each of the axon from the retina that has passed the lamina targets one of these specific regions. The axons placed into the medulla are responsible for color processing and work to signal different parts of the fly's brain about color. Both sets of neurons (the ones for motion and color) use hedgehog to locate their exact resting location in the cell. Of course, a handful of other proteins are used too and things become fun.

The actual article is extortionately in depth and would take a paper just as long as the journal article to write about. However, it does give a much more detailed account of the generally too simply and incomplete overview have given. Read up, if you'd like.

Busy Beavers and Huge Fish

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Doing research for a paper due this week, I stumbled across an interesting article published in 1974. The article described observations made by a group of scientists on a den of beavers which they claim ran on 27 hour circadian rhythm for months at a time. I went to do some more research on the validity of the claim and found no evidence supporting this journal article in the last thirty-five years, except from beaver lover blogs. The article suggested because of the extreme dark experienced in the dam, beavers set themselves to a social circadian rhythm. I thought the idea of other animals being zeitgebers was interesting, but so far, no other evidence has led to this conclusion. Somethings are just too mildly interesting to be true, ah?

I stumbled into another article this weekend while trying to find information on paddlefish. I thought this article was interesting too because so much effort was put into finding one of these fish and still no results were obtained. The Chinese paddlefish itself is pretty interesting because of the sensory rostrum, which is used passive electrical detection is long and thin, in contrast to the American broad and long rostrum. The species in heavily endangered so I doubt any research will be coming out soon or for that matter, ever regarding the function of the nose. The fish still looks pretty cool and if anyone digs up some stuff on this beast, please let me know.

Arc and Memory

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The gene, Activity-regulated cytoskeletal protein or Arc is known for its role in the storage of long term memories. Arc was first identified as having this role when mice with the gene knocked out displayed totally normal short term memory but had close to zero long term memory. The gene activates when promoted to do so from a handful of singling proteins which are activated by a handful of neurotransmitters, and when activated, in a single statement, Arc simply creates dendrite projections fairly quickly after being stimulated (within a hour). The expression of Arc happens in waves, the first which happens within the hour of the stimulation, the second follows a few hours later, and the third sometime after. The reason for expression in waves in not completely understood but it is believed the initial waves are preparatory activity, like most things biological, which creates feedback loops activating more genes which eventually allow for proper expression of the gene.

While Arc is not known to have any direct roles in disease, in Arc knock mice are known to be highly prone to seizures. I wrote about this article because as someone who experienced seizures for many years of my life I found it interesting. Pentobarbital is a drug I was put on for a short while which caused my seizures to get worse, this drug works deregulating singles across the entire brain. While, it is stated working on the whole brain equally, its use as a sleep aid and to treat people with traumatic injury, one could assume it works particularity heavily on the hippocampus. Arc, in order to work, need a ton of different singling molecules and so one would assume the function of the gene (with all its feedback loops) would probably be affected by Pentobarbital. This would explain why a fairly large number of patients who take Pentobarbital also experience an increased number of seizures, as it is also known a lack of expression of Arc causes seizures. Pentobarbital is no longer prescribed as a primary treatment to seizures (usually other things are tried first) but I would be interested in knowing if Arc is the reason why increased seizures are experienced.

If you would like to read the journal article it can be found here, and please don't stop taking your medicine, I am not a healthcare professional and this is not medical advise.

Genes, Coffee, and a T-Shirt

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One of the most widely consumed substances in the world is coffee. Known by most of us for its smell, great taste, and awaking affects, coffee is a regular part of people's lives. On top of the great things we consciously know coffee does, it also decreases an individuals likely hood of developing Parkinson's disease, dementia, and Alzheimer's disease. Coffee's stimulating power, caffeine, has been well investigated however, it is still not clearly understood why coffee, as opposed to other caffeinated beverages, reduces one's chances of developing certain neurologically diseases.

Recently however, CYP1A1 and CAB39L were announced as possible candidates of the effectiveness of coffee at neurological disorder prevention because both showed activity when coffee entered into cells. CYP1A1 was down-regulated as coffee entered cells, while CAB39L was up-regulated around the same time. CYP1A1 is known to metabolize polycyclic aromatic hydrocarbons, coffee is known to have these polycyclic aromatic rings (interesting that this could be beneficial in some manner, ah?). CAB391L on the other hand is known as a calcium binding protein. A direct correlation has not been established between the activity of these genes from coffee consumption and the decrease in neurological diseases.

I thought this study was neat because it addressed a particular substance that was not an isolated chemical. The article seemed to still be very thorough in its methods even with an enormous sample size and rather difficult topic to approach. The article is fairly detailed, read up if you would like to know more.

A Better Illistration of Right V. Left

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When taking an intro psychology class most people learn some nonsense about how the brain is segregated into the right and left hemisphere, one which does everything logical and other everything creative. When taking an intro neuroscience class one learns, and quickly, the brain is a cohesive organ that is much more complex than the simply division psychology books sometimes make it out to be. However, the brain is divided and a video by Iain McGilchrist explains this beautifully.

The video starts off with brief introduction where misconceptions between the right and the left side of the brain are demystified. The human brain is then introduced as being the organ that works to slow things down so we can step back from the world. The corpus callosum is labeled by the video as the layer of cells most responsible for the retardation of these communications from the outside to our cognition.

McGilchrist goes on to explains the right side of the brain is not so much creative as it is broad spectrum side of our minds. The right side scans for discrepancies in our environment, that is the things we do not expect. The right side perceives the the body and other parts of the world as separate pieces removing the biases we approach things with. The right side of the brain is the child like approach to the world that is often talked of a gone missing, our Hubble telescope, exploring the deep unknowns of our daily lives.

The left side is more focused, it works on making what we see concrete. McGilchrist describes it as the lifeless organ that works towards perfection to the point of emptiness. He explains how the left allows us to put things into categories, manipulate our environment, and think ahead of the other party. He describes the left as not so much our logical side but the side that is capable of logic amongst related tasks that involve focus.

The video incorporates an evolutionary perspective, cartoon drawings along the way that keep the video funny and interesting, and is filled with neat facts but rotates slowly enough to where concepts can be taken home easily. On the down side it has the feeling of a conspiracy theory or self help video to it, even though it is informative it makes one uneasy at the thought of who this video was marketed towards (am I silly for liking it? please feel free to comment back). All and all, I would recommend watching it, at the very least it is an entertaining 12 minutes.

A Quantitative PET 4-aquaporin (AQP4)

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Aquaporin 4 channels or AQP4 channels are water channels distributed heavily within the central nervous system. The AQP4 channel are of interest to scientists because they are known to cause or be involved in a few different types of brain disorders. The next question is what goes wrong in these channel and how to treat it. However, another important question must be answered before treatment. How does one know what areas of the brain are being affected my non-funcational AQP4 channels?

The answer to this question is 2-nicotinamido-1,3,4-thiadiazole (TGN-020), a recently developed AQP4 channel block which when synthesized with a carbon-11 isotope allows for PET scans to pick up on where functional AQP4 channels are located by blocking the functional ones. The development on TGN-020 has been proven affective in mice at locating AQP4 channels and will hopefully help shed light on the causes or the effects of certain human brain disorders.

I thought this article was interesting because of the methods used. The study took regular mice and gave them TGN-020 and took pictures, then they took mice with AQP4 knocked out and administered the same amount of the drug and took pictures. They compared the two results, but the interesting thing about this is that they took the extra step. Not only was it enough to prove TGN-020 had infinity to AQP4 (which they had done in prior experiments) they also wanted to prove how how much compared to baseline levels (that don't exist in nature).

One can take the amount of pick-up from non-AQP4 aquaporins, from the mice without AQP4 (these channels do resemble each other some, so while selective, nothing is 100% exclusive), and subtract it from the AQP4 mice's results. The subtraction would give accurate readings on how much and where was AQP4 activated in the mouse. The part that struck me as being neat here is how much time this is going to save someone who is trying to figure this same thing out in humans, because unlike mice we can't just knock out AQP4 channels but you can apply the results from mice, into people to give a lot better estimate.

Kudos The University of Niigata, you win. If you would like to read the article it can be found here.

Embryonic and early post-natal development are crucial periods in determining the expression of certain traits in an organism. Environmental factors can influence crucial periods of development, these factors can be physical (things such as chemicals, nutrition, radiation, ect...) and positive (the presence of something causing harm) or negative (a lack of something can cause harm too). Today I would like to present a negative-nutritional affect in post-natal development dealing specifically with cell proliferation in the hippocampus of mammals and how it relates to cognitive impairments and disorders.Or more simply, how malnutrition in babies (humans or rats) leads to slowed learning, depression, and schizophrenia.

This study focused specifically on an observed phenomena that mammals reared in an environment lacking proper nutrition often have a higher frequency of sub-average cognitive abilities. The study worked at answering whether this phenomena was due to cell differentiation or cell proliferation being stopped.

The study found malnutrition works by stopping proliferation not differentiation. The study came to this conclusion based on variations in their experimental design that boosted the malnourished rats nutrition, which allowed them to make a almost full recovery, both the recovered and well fed rats expressed more of a particular type of neuron however, had the same number of types. If cell differentiation had been the cause, this could not have happened because when given more nourishment one should have seen an increase in types of cells (not to mention if it was due to cell differentiation, one could have just used the number of types of cells from the initial two groups). The study concluded by speculating that the depression and schizophrenia associated with malnutrition is probably due to the recovery stage (when nutrition is available) increasing cell proliferation and delaying neurogenesis which results in neurons that are not trimmed to function.

This article is extremely detailed, if you are interested, you should read up.

For Names Sake

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When watching television it is not uncommon to see an add for this or that product which blocks allergies or increases dopamine release and from this information one can conclude what the product could be used for. The field of neuroscience is no different, substances are given a name and when testing them its function is determined. Take the any ion channel in the body for example, a substance that increases its function is called an opener and a substance that reduces its function is called a blocker.

A substance that increases an enzymes function is called an opener, that's straight forward right? Now imagine you just get done taking a run and you have a cup with a lid and straw that is a quarter full of water (remember you are thirsty and have to optimize what you have!). You would want to get the most water out of the cup as possible, so maybe you take and lid off and remove the straw between the water and you, maybe you get a bigger straw so you can drink the water quicker, or maybe you could cloud seed the entire sky and have all the water you could want. The first two examples play by the rules, the second just changes the environment.

This is often the case with openers and blockers, they often work by affecting the environment around the cell. Take Retigabine for example, this Kv7 potassium channel opener that it works by inhibiting higher membrane potentials (that does sound like it opens the channel any).

In a recent research paper I did I found a number of examples like this, which I just found humorous, see scientists can be just and silly and illogical as everyone else!

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Recent Comments

  • donnasmith351@yahoo.com: The article is pretty interesting and I am thanksful to read more
  • frenz059: Thank you for your comment Dizzi. I believe this journal read more
  • dizzi90@gmail.com: But if she is too forgetful to know it was read more
  • dizzi90@gmail.com: Sweet. Can't wait to play that game. I wish they read more
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  • oc1dean@yahoo.com: I commented too soon, you may want to look at read more
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