LMAYQ: Cellular Cells

Time to get back to Answering Some Questions. Where I attempt to answer the search-engine questions which have led you to The Cellular Scale. I mainly try to answer questions that I am sure are not answered anywhere on this blog. 

1. "What does a cellular cell look like?" 

Good question. First of all, what is a cellular cell? Is it different from a regular cell?
Cells look like all sorts of things. Some look like footballs, some look like sea coral. Some cells look like little rafts, drifting down a river.

Blood rafts (source)

Hitch a ride on a blood cell this summer (source)

2. "What song does Shrek sing in Shrek 1?"

 I have no idea. However, I remember the song "I like big butts" being in that movie. I am not certain that Shrek sings it. It might be the donkey.

As a side note, I am glad that this blog has become the go-to place for Shrek questions. After all, Shrek and Yoda do stimulate your neurons.

3. "Why does golgi not stain all cells?"

This is a real true very good question. The strength of the Golgi stain lies precisely in its sparse labeling. If it labeled all cells it would be useless because you wouldn't be able to see the elaborate morphology of a neuron's dendrites.

However, even though it has been around for almost 150 years, it is still unclear why it doesn't stain all cells. It is not clear how it 'decides' to stain one cell and not the one next to it. This is always a bit of a problem for people wanting to use the Golgi stain, because you always have that nagging feeling that maybe you are seeing only the sick neurons or only the neurons with random undiscovered quality X, and so forth. But it is a well respected technique, and journals regularly publish scientific articles which rely on the Golgi stain.




© TheCellularScale

Official SfN Neurobloggers 2013

Due to starting a major simulation this summer, I am not going to the annual society for neuroscience meeting in San Diego this year. And therefore I won't be neuroblogging it like I did last year.

I look forward to reading the posts and tweets from the official neurobloggers this year.

Here they are:

From Brains to Beyonce by @Spork15

House of Mind by  @houseofmind

Neuron Physics by @Eric_Melonakos

NeuroscienceDC by @NeuroscienceDC

Neurolore by @TheMrsZam

NeuroCultureBlog by @LaSaks87

Churchland lab by @anne_churchland

Dormivigilia by @beastlyvaulter

Neurorexia by @ShellyFan

On Psychology and Neuroscience by @astroglia

Más Ciencia por México by @mrenteria_

Imagining Science by @DrImmySmith

Corona Radiata by  @JohnKubie


Follow the #SfN13 hashtag on twitter to find all the unofficial coverage of the conference.


© TheCellularScale

The Ultimate Simulation

You may have noticed that things have slowed down here at The Cellular Scale.

The reason is that I have been really busy making the ultimate simulation of a human brain. I've worked on this day and night for the past 8 months. It is exhausting work and is starting to take all my energy now that it is nearly complete.

Pretty soon I will have to push this simulation out my uterus, and then all my effort will be spent on simulation support and maintenance. I may write some posts, but they won't be appearing regularly for a while.

© TheCellularScale

LMAYQ: Mirror Neurons

Mirror neurons really excite people. They've been hyped as the root of empathy and essential to human nature. I've addressed some of this hype, but questions remain. So for this edition of Let Me Answer Your Questions, we will focus on mirror neurons. As always, the LMAYQ series can be found here.

Escher's Mirror (source)

1. "What do mirror neurons look like?" 
Good question, and guess what? I have addressed this directly.

2. "Do mirror neurons fire when you die?"
Another good question. Ultimately, all neurons stop firing when you die including mirror neurons. But this doesn't happen immediately. In fact, if the death is due to something traumatic such as decapitation, the neurons might fire more when the nerves are severed between the spinal cord and the brain. But this just brings up questions about the moment of death. Is it when the heart stops, the head is severed? or is it when the neurons stop firing? Can a 'person' be dead when some of their cells are still alive?

In a lot of cellular-level research, cells are kept alive after the animal that they came from has died. Electrophysiologists keep slices of brain alive for hours to record electrical signals from their neurons. Still other projects involve culturing neurons that have been extracted from an animal. These neurons are carefully tended for days, weeks, and even months. These neurons not only stay alive in little dishes, but they can also grow and even control robots.

There are living neurons in there (source)

3. "what does it mean to have a mirrored brain?"
Well. nothing really. I have never heard the term 'mirrored brain' before, and it sounds like something that might be in a pseudo-scientific quiz along the lines of Are you left brained or right brained?  "Do you have a mirrored brain? take our quiz and find out"

4. "Is love nothing but mirror cells?"
I love and hate these kinds of questions. The idea that love is nothing if it can be explained by a biological mechanism really gets me. If love is just neurons firing (mirror or otherwise), so what? Why would that make LOVE any less meaningful?

Heart Mirror (source)

On the other hand, this is a really interesting question if it is asking whether mirror neurons have anything to do with love. Again mirror neurons are neurons that fire when you do something and also when you see someone else do that thing. Specifically, they were discovered in monkeys when monkeys reached for something and then saw other hands reach for something. Then the concept got hyped up. It's easy to imagine that if you have neurons that fire when you do something and when you see some one else do that same thing, that those might have something to do with 'feeling another's pain' and thus empathy. So it's not a huge step to take from there to think that maybe mirror neurons could have something to do with building relationships and love.

But the speculation here is WAY beyond the science. There isn't good solid evidence for mirror neurons controlling empathy, and certainly not for being the basis of love.

 © TheCellularScale

LMAYQ: Scales

The word "scale" can mean many things, and The Internet can't yet use context to tell the difference. So for this issue of Let Me Answer Your Questions, here are questions about scales that The Internet thinks The Cellular Scale can answer. As always these are real true search terms, and all the posts in the LMAYQ series can be found here. 

A Question of Scale (source)

1. "Can you give a rat scales?"

 I have never thought to ask this question, but it is an interesting one. If you can grow weird things on mice, like ears, then why not scales? Well here's the thing, the 'ear mouse' is growing skin like it normally does, the skin is just growing over an ear-shaped mold. It would actually be harder to make a rat grow scales. If it is possible, it would take some mastery in genetic manipulation...

Bee-Rat, the ultimate achievement in genetic manipulation (source)

Some sniffing around on wikipedia taught me that scales have evolved several times (fish, reptiles, arthropods, etc). It might be possible to make a rat (or mouse) grow scales by isolating the scale gene from these other animals and inserting it into the rat genome. However, since rats already grow fur, teeth, and nails, which are related to scales, it might be possible to manipulate those features already in the rat to become more scale-like.

But to answer your question, no. I am pretty sure we can't give a rat scales yet.


2. "Does the giant squid have scales?"

Another interesting question. The quick answer is no, giant squid and colossal squid (like their normal squid counterparts) have smooth skin that does not contain scales. This isn't too surprising because squid aren't fish, they are cephalopods (like octopus and cuttlefish). Cephalopods sometimes have shells, but not scales. 

Zoomed in view of Squid Skin (source)

Instead of protective scales, cephalopods use pigment in their skin to camouflage themselves or confuse predators.

Blue Octopus, Eilat Israel (I took this picture)

This octopus turning blue sure confused me.


3. "How to turn your cell phone into a scale."

There are a couple of ways that you might think a cell phone could be used as a scale. One is by the touch screen sensor. However, most smart phones now have capacitive touch screens which respond to the electric change your finger induces on the screen. That means that the amount of pressure applied doesn't matter. So you couldn't use a smart phone as a scale in that way.

Another way is through the accelerometer. Smart phones also have accelerometers, which you could possibly use to measure the force of something moving. But this wouldn't tell you the mass of the object unless you already knew the acceleration. (force = mass * acceleration). 

But really the only way that seems to actually work (albeit slowly and with questionable accuracy) is using the 'tilt sensor' of the smart phone.

But really you just as well make your own if you are weighing out small amounts of something.

Most importantly it's helpful to know what some typical objects around the house weigh, so you can use them to calibrate a phone or homemade scale.  Here are some useful weights:

1. US penny 2.5g
2. US nickel 5 g
3. 1ml water 1g
4. Euro 7.5g
5. British pound 9.5 g



4. "What is the scale on the cellular level?" 

Finally a relevant question! Most cells are measured in microns, with a blood cell being about 6-8 microns in diameter.

blood (source)

Neurons on the other hand can have somas (cell bodies) ranging from tiny (5 micron diameter) to large (50 micron diameter). But even for neurons with small somas, the dendritic or axonal arbors can be gigantic. 

Some neurons in the aplysia (snail) can get up to 1mm (1,000 microns) in diameter. Which is ridiculously huge for a neuron. For perspective, C. Elegans, a nematode frequently used for neuroscience research, is about 1mm in length. The whole animal! Including its 302 neurons! 

© TheCellularScale

What is up with the "Dopamine Project"?

Someone is trying to make me eat my words.

yum. (source)

That someone is the Dopamine Project. I am on record as saying "It is better for the public to learn simplified bite-size science morsels than to learn nothing at all." And my specific example was that it's better for people to know that 'dopamine is a reward molecule' than to not even know the term dopamine.

But sometimes things just go too far. The "Dopamine Project" is a website run by Charles Lyell with a stated 'self-help' purpose:

"The Dopamine Project was founded to foster positive change by encouraging open-minded individuals to share readily available research into the connections between dopamine and a growing list of addictive behaviors." -About Tab

Doesn't sound too terrible, right? Share research about dopamine? sign me up! .... However, I don't see ANY research, or even references to research, on this website. In fact it's quite wootastic. Going through the posts, you get some gems like

"A Message from you Dopamine Angel"

and

"Keeping a Dopamine Diary: Wrestling with Dopamine-Induced Ignorance"

It's all about how 'good dopamine' makes you want things you should want (food) and 'bad dopamine' makes you want things that will hurt you later (addictive drugs for example). Basically the website's message is a self-help, self-control one with the word dopamine sprinkled all over it.

The worst part is that not only does the website not include a single citation to a research paper, it actively rails against science.

"The future depends on how long it takes scientists to discover what they haven’t been interested in discovering so far. Rather than wait for the mainstream scientists and media to get started, we’re reaching out to anyone interested in fostering positive change by raising dopamine awareness." -Welcome to the Dopamine Project

Trust me, scientists want to understand dopamine. At the IBAGS conference half the talks related to dopamine, and there is a conference completely devoted to dopamine coming up in May. The specific action of dopamine is really really complex, and scientists are working really really hard to unravel its intricacies. This Charles Lyell guy is pulling out a typical woo card, implying that he knows what scientists don't want you to know.

"If the thought of fostering positive change through dopamine awareness triggers a shot of dopamine that brings a smile to your face, this might be your chance to be among the top .001% who go on record as the first to understand and apply what we know about dopamine to make a difference."  -Welcome to the Dopamine Project

 He also seems to feel personally attacked by Steven Poole's New Statesman article on Neurobollocks.

Is the 'Dopamine Project' ridiculous and unscientific? Absolutely.

Is it harmful and dangerous to people? ... Honestly, I'm not sure. Reading it certainly makes me want to throw up, but there are worse things for pseudoscience to encourage than self-control. I'm not sure if I should devour my earlier words quite yet.

© TheCellularScale

To read more on the confusing line between science and pseudoscience, see Michael Shermer's Scientific American article:



Shermer M (2011). What is pseudoscience? Scientific American, 305 (3) PMID: 21870452

LMAYQ: Let me do your homework for you

Sometimes reading the textbook is just too hard. And sometimes it's much easier just to type your exact homework question into a search engine and find the answer. Before we get started you might want to take a look at Smith and Wren (2010) "What is Plagiarism and how can I avoid it?" 

This edition of Let Me Answer Your Questions will address 'homework questions.' As always, you can find previous LMAYQ questions here.

Tough Homework Questions are for the Internet (source)

1. "cells that fire together a) wire together. b) definitely don’t wire together. c) become overheated and die. d) wire with inactive cells." Ok, student. If you have to turn to the Internet for this multiple choice question, you need a serious lesson in test-taking skills. Here's a tip. If you don't know the answer, eliminate some because they are obviously not the right answer. A good rule to follow is if it says definitely or all or always in the answer it is unlikely that that is the right one. So we can eliminate B. If you know anything about neurons from your class, you should at least know that neurons fire. If they didn't fire they wouldn't 'work'. So you can eliminate C. If all the cells that fired together overheated and died, you would basically not have any neurons left in your brain after reading this sentence. Now you have a 50-50 chance of guessing it correctly. Not too bad. But seriously, if one answer creates a cute little rhyme with the question... it's probably going to be that one. So yes, neurons that fire together wire together. 2. "explain simply where the hippocampus is" The hippocampus is one of the most famous brain structures because it has to do with encoding new memories. It's name comes from the Greek hippo (horse) and campus (sea), because it looks like a seahorse: Hippocampus = Seahorse (source) (By the way, potamus=river, so a hippopotamus is a 'river-horse'). Back to the hippocampus: It is a structure in the brain and it is located subcortically meaning under the cortex. Specifically it's located under the temporal lobe of the cortex. There are two of them, one on each side of brain. 3. "Why are neurons and blood cells structured and shaped differently from each other?" Neuron and Blood cell Knitting (by Estonia76) This is a great question, but it has the ring of 'I need help with my homework' about it. I talk a lot about the shapes of neurons in this blog, usually speculating on why different neurons would be shaped differently from each other. But this is a good question, why do neurons have dendrites and axons in the first place? Well basically neurons need to receive and transfer information, while blood cells need to physically move to transfer oxygen. Neurons stay in place, while blood cells travel all over the body. Blood cells need to be small and hydrodynamic to float through your blood vessels. Neurons need to 'cover space' to contact many other neurons, so they have branching dendrites and axons. © TheCellularScale Smith N Jr, & Wren KR (2010). Ethical and legal aspects part 2: plagiarism--"what is it and how do I avoid it?". Journal of perianesthesia nursing : official journal of the American Society of PeriAnesthesia Nurses / American Society of PeriAnesthesia Nurses, 25 (5), 327-30 PMID: 20875892

LMAYQ: Why do I like that?

Again it is time for me to answer some questions. As always, these are real true 'search terms' that have resulted in some one finding The Cellular Scale. While some questions (like 'how do you build a model of a neuron') are answered by this blog, the ones I answer is these LMAYQ posts are almost certainly not. All the questions and answers in this series can be found in the Let Me Answer Your Questions index.

Drawing by Grave Unicorn

1. "Why do I like ketamine so much?"

This is actually a pretty interesting question. Ketamine is a psychoactive drug known to cause hallucinations and feelings of dissociation, but it's not thought to be super-addictive in the same way that heroin or cocaine are thought to be. So why do you like it?

First let me get a 'safety warning' out of the way. Even though research is currently being conducted to investigate ketamine as an acute anti-depressant and to investigate its possible role in neurogenesis, it is not all considered a safe drug. It can seriously damage your urinary system for one thing, and probably damages your brain. Don't take it.

Ketamine (source)

Having said that, ketamine might give you a 'good feeling' because it is a partial agonist (meaning helps activate) the dopamine D2 receptor and the serotonin 5-HT2 receptor. In 2002, Kapur and Seeman published a paper showing that ketamine (and PCP) affects the dopamine and serotonin system by binding to these specific receptors. However dopamine is a confusing molecule and the idea that ketamine activates the D2 dopamine receptors does not necessarily mean 'pleasure.'

A classic test of 'wanting something' in rats is the self-administration paradigm, where rats can press a lever and get a dose of some drug or an electrical stimulation directly into the brain. A recent paper by De Luca and Badiani (2011) shows that rats will self administer ketamine when given the chance.
Interestingly, they found that the amount of self-administration was much higher when they took the rat out of its cage and put it somewhere new for the self-administration session. When the rat was allowed to self-administer ketamine in its home cage it just didn't give itself as much.

So your 'liking' of ketamine might have to do with where you are when you do it.


Kapur S, & Seeman P (2002). NMDA receptor antagonists ketamine and PCP have direct effects on the dopamine D(2) and serotonin 5-HT(2)receptors-implications for models of schizophrenia. Molecular psychiatry, 7 (8), 837-44 PMID: 12232776

De Luca MT, & Badiani A (2011). Ketamine self-administration in the rat: evidence for a critical role of setting. Psychopharmacology, 214 (2), 549-56 PMID: 21069515



2. "What do neurons like?"

This question cracks me up because it reminds me of two personal anecdotes. First it reminds me of one of my professors who just can't stand when people say "the neurons behaved this way or that way." The idea being that behavior is a thing animals do, not a thing that neurons do. I basically agree that neurons don't behave per se, but I also don't really care if someone wants to 'be cute' by anthropomorphizing a cell.

Second, thinking about neurons 'liking' things or being happy reminds me of a yoga class when during the final relaxation segment, the teacher started saying things like 'You are happy. Your cells are happy, they are all smiling at each other.' It was hard for me to relax and let my cells smile at each other when all my willpower was being engaged preventing me from bursting into laughter.

Regardless, I will do my best to answer this question. I suppose, neurons 'like' glucose, which gives them energy. Other than that I don't think it's meaningful to talk about neurons liking things.


3. "Why do men like big women?" 

This is one of a long string of questions that resulted from me having the words 'small', 'men', 'like', 'big', and 'women' all in the title of a post. As you might imagine, this is far from the worst 'search term' that has dropped people onto that page.

And believe it or not, this question has a scientific answer.

A paper this year by Swami and Tovee (2012) investigates the influence of stress in men's judgement of women's bodies. They found that men who were stressed for just 15 minutes (by being forced to give a speech explaining how suitable they are for a job) found 'bigger' women more attractive than the men who were not stressed did.

Poor guy, if only he had a nice motherly type to cook him a pie. (source)

The 'explanation' could be (though this is speculation, of course) that bigger women represent more 'security.'

"The Environmental Security Hypothesis [15]–[16] suggests that, when socioeconomic or individual conditions are threatening or uncertain, individuals will prefer others with more mature physical characteristics, including a heavier body size, compared to their preferences in non-threatening conditions. This is because physical maturity is associated with the ability to handle threatening situations and because more mature physical features may communicate attributes such as strength, control, and independence during periods when such qualities should be most desired [15]." -Swami and Tovee (2012)

This paper is covered in more detail over at TryNerdy, and the paper is open access so you can read the source material if you want.


Swami V, & Tovée MJ (2012). The impact of psychological stress on men's judgements of female body size. PloS one, 7 (8) PMID: 22905153

 
© TheCellularScale

On Selling and Over-Selling Science

Science!!! (source)

Science communication is a persistent topic of ... well communication. Who is responsible for communicating science? How can science be best communicated to the public? What can we to do stop sensationalist and misleading articles from controlling what findings are generally accepted in the public sphere?

All these questions rise up in science blogs and on twitter and then fade back into the background. Then something happens and a flurry of posts about communicating science float to the surface again.

I have decided to join this party, and have written a Guest Editorial at the Biological Bulletin.

It's called "On Selling and Over-Selling Science" and is about trying to find that perfect balance between communicating a scientific finding accurately and accessibly.

I'd love to hear new opinions on this. So feel free to follow the link and leave a comment about it here. 

© TheCellularScale

I was not able to use my 'blogging name' like Neuroskeptic was, so here is the article and my identity along with it:


Evans RC (2012). Guest editorial on selling and over-selling science. The Biological bulletin, 223 (3), 257-8 PMID: 23264470

Cellular Recap of 2012 #2: favorites

As promised, here are my favorite posts from each month.

January: The Human Neuron" not so special after all?

Butti C, Santos M, Uppal N, & Hof PR (2011). Von Economo neurons: Clinical and evolutionary perspectives. Cortex; a journal devoted to the study of the nervous system and behavior PMID: 22130090

February: If you give a mouse a placebo...

Wise RA, Wang B, & You ZB (2008). Cocaine serves as a peripheral interoceptive conditioned stimulus for central glutamate and dopamine release. PloS one, 3 (8) PMID: 18682722 

March: Plant neurons: Sensation and Action in the Venus Flytrap

Benolken RM, & Jacobson SL (1970). Response properties of a sensory hair excised from Venus's flytrap. The Journal of general physiology, 56 (1), 64-82 PMID: 5514161

Volkov AG, Adesina T, & Jovanov E (2007). Closing of venus flytrap by electrical stimulation of motor cells. Plant signaling & behavior, 2 (3), 139-45 PMID: 19516982  

Forterre Y, Skotheim JM, Dumais J, & Mahadevan L (2005). How the Venus flytrap snaps. Nature, 433 (7024), 421-5 PMID: 15674293

April: Real or Not Real? Neurotorture

Kindt M, Soeter M, & Vervliet B (2009). Beyond extinction: erasing human fear responses and preventing the return of fear. Nature neuroscience, 12 (3), 256-8 PMID: 19219038

May: Dendrites of Direction

Kim IJ, Zhang Y, Yamagata M, Meister M, & Sanes JR (2008). Molecular identification of a retinal cell type that responds to upward motion. Nature, 452 (7186), 478-82 PMID: 18368118

Kay JN, De la Huerta I, Kim IJ, Zhang Y, Yamagata M, Chu MW, Meister M, & Sanes JR (2011). Retinal ganglion cells with distinct directional preferences differ in molecular identity, structure, and central projections. The Journal of neuroscience : the official journal of the Society for Neuroscience, 31 (21), 7753-62 PMID: 21613488

June: What do Mirror Neurons look like?

Kraskov A, Dancause N, Quallo MM, Shepherd S, & Lemon RN (2009). Corticospinal neurons in macaque ventral premotor cortex with mirror properties: a potential mechanism for action suppression? Neuron, 64 (6), 922-30 PMID: 20064397

Casile A, Caggiano V, & Ferrari PF (2011). The mirror neuron system: a fresh view. The Neuroscientist : a review journal bringing neurobiology, neurology and psychiatry, 17 (5), 524-38 PMID: 21467305 

July: The Shape of a Memory

Blackiston DJ, Silva Casey E, & Weiss MR (2008). Retention of memory through metamorphosis: can a moth remember what it learned as a caterpillar? PloS one, 3 (3) PMID: 18320055


August: How to Build a Neuron: Step 1

Marx M, Günter RH, Hucko W, Radnikow G, & Feldmeyer D (2012). Improved biocytin labeling and neuronal 3D reconstruction. Nature protocols, 7 (2), 394-407 PMID: 22301777 

September: Taste cells in weird parts of your body

Finger TE, & Kinnamon SC (2011). Taste isn't just for taste buds anymore. F1000 biology reports, 3 PMID: 21941599
 

 October: Can you turn a rat gay? 

Triana-Del Rio R, Montero-Domínguez F, Cibrian-Llanderal T, Tecamachaltzi-Silvaran MB, Garcia LI, Manzo J, Hernandez ME, & Coria-Avila GA (2011). Same-sex cohabitation under the effects of quinpirole induces a conditioned socio-sexual partner preference in males, but not in female rats. Pharmacology, biochemistry, and behavior, 99 (4), 604-13 PMID: 21704064


 November: Growing 3D cells 

Labour MN, Banc A, Tourrette A, Cunin F, Verdier JM, Devoisselle JM, Marcilhac A, & Belamie E (2012). Thick collagen-based 3D matrices including growth factors to induce neurite outgrowth. Acta biomaterialia, 8 (9), 3302-12 PMID: 22617741

December: Cortical spine growth and learning how to eat pasta

Fu M, Yu X, Lu J, & Zuo Y (2012). Repetitive motor learning induces coordinated formation of clustered dendritic spines in vivo. Nature, 483 (7387), 92-5 PMID: 22343892

© TheCellularScale