Thursday, December 31, 2009

Body Worlds "Too"

As a holiday present, my lovely wife bought us tickets to the new Body Worlds exhibit at the Franklin Institute in Philadelphia.  This is the second showing of a Body Worlds exhibit at the Franklin, and this "BodyWorlds2" is supposed to have a special emphasis on the brain (thus, despite our having seen the first exhibit several years ago, the wife and I thought we would enjoy going to see this exhibit as well).  I have to say that we did enjoy both trips to the "Body Worlds", and if you haven't yet seen one of these exhibits, I highly recommend it.  (If you have no idea what BodyWorlds is, you can check out their website here.)  The preservation techniques and the human specimens (as well as those of sheep, horses, camels and other animals) really are stunning, and give you a first-hand look at several different facets of anatomy that you could only get in a college (or really graduate level) anatomy lab. In many cases, you wouldn't get such a clean or clear cut look from a med school cadaver as you do in many of these "plastinates" (like in the images below which show a specimen where only the blood vessels are preserved, and another where all of the nerve tracts have been preserved). 
My only gripes about the exhibit were (a), if you've seen it before, there really weren't that many new specimens than the first exhibit (thus my desire to change the title to BodyWorlds " Too"), and (b) for an exhibit that was supposed to be focused on the brain and the nervous system, I was disappointed at the lack of emphasis on neuroanatomy.  It seemed to me like we were basically seeing the normal BodyWorlds exhibit, but with a few posters here and there to tell us about some of the things going on in the brain (like how emotions seem to be predominantly processed in the limbic system, or how music can stimulate many areas of the brain, etc.)  These posters however were oviously not the highlight of the show, and in many cases seemed to be only an afterthought, which was evidenced by the fact that there did not seem to be any sort of unifying theme, or reasonable order in which they were presented (many of the ones that actually pointed out brain structures were well after, and in completely different rooms from the actual brain specimens, and most of them were poorly showcased and off to the side).  At the risk of using (or misusing) one of the buzzwords of the past decade, I think the Franklin missed out on a great "teachable moment", and I don't think anyone leaving that exhibit will have any real grasp of even the most fundamental and important concepts in neuroscience (or in neuroanatomy).  That being said, the exhibit is still worth seeing, and you will definitely learn some interesting bits and facts here and there, but I think mainly the purpose is to inspire awe at the human form and to excite viewers to want to learn more about biology, medicine, and anatomy.  In this respect, I think that the show truly succeeds, but then, we already know that I love biology, so maybe I am biased.

Wednesday, December 30, 2009

Okay, so it's not neuroscience,

But I have had several people asking me to share my view on the whole "Climategate" SNAFU.  I'm sure you can probably guess, but to be blunt, I think it is a complete load of crap.  If I had to sum up my feelings as succinctly and eloquently as possible, I would simply quote the great Harvard naturalist Stephen Jay Gould who said:
"When people learn no tools of judgment and merely follow their hopes, the seeds of political manipulation are sown."
Since I am nowhere near as succinct or eloquent as Dr. Gould, here is my response to anyone who would claim that global warming is not real, but rather the product of some vast conspiracy within the science community:
If you don’t accept the mountain of evidence that conclusively shows that the earth is warming AND that this climate change is impacted by human activities, then you are either (1) IGNORANT (that is, unaware of the aforementioned mountain of evidence) or (2) PUROPOSEFULLY OBTUSE AND DECEITFUL (likely for some political or monetary gain), or (3) both (1) and (2). It is an unfortunate fact that the majority of Americans have a poor understanding of science and the nature of scientific evidence, which leaves them susceptible to being deceived by those who have financial or political interests in discrediting the evidence. It seems that history does repeat itself, and the current campaign of the “climate deniers” is remarkably reminiscent of how the tobacco industry successfully parried claims and undermined research for decades, somehow casting doubt on the overwhelming evidence that showed that smoking causes cancer (which was first shown as early as the 1700s, unequivocally confirmed in the 1950s, and yet not really accepted until the late 1980s or 90s). All of the political pundits making so much hoopla out of these “Climategate” emails seem only to be able to point to THREE lines taken from a COUPLE of emails that have been cherry picked and taken out of context from over 10 years of emails, and then, they claim that these THREE LINES somehow topple the DECADES of research carried out by HUNDREDS of scientists and published in THOUSANDS of scientific journal articles. And what is this “trick” everyone is so upset about? Well, rather than use tree ring data (which becomes unreliable as a measure for seasonal temperature when CO2 in the atmosphere increases beyond a certain point) the scientist in question used the ACTUAL TEMPERATURES recorded over the past 30 years. So he was “hiding” what looked like “the decline” in tree ring data, by SHOWING THE ACTUAL INCREASE IN AVERAGE TEMPERATURES! This is not some massive conspiracy/cover-up, it is actually STRONGER evidence that the earth is warming. I’m not going to spend the time to fully disabuse this nonsense here, but if you want to see where else this “ClimateGate” BS falls flat on its face you can go here:

or here if you actually want to see photographs of glaciers and ice caps melting away…

If you really want to know what’s going on, look up the evidence for yourself, don’t just believe fat mouths like Glenn Beck and Rush Limbaugh who are, of their own self-proclamation “entertainers” rather than experts. And don’t take me at my word either if you don’t want to, but don’t claim “flawed science” if you haven’t even looked at the science, or the reports of the hundreds of hard-working people whose decades’ worth of work have been casually and carelessly cast aside because one or two comments in some emails have been horribly misconstrued and taken out of context and then plastered on your tv.

Sunday, December 27, 2009

Aluminium and Alzheimer's disease

I've been planning on writing about this one for a while now because I feel like it's almost as prevalent a  myth as the vaccines and autism notion (which may just get its comeuppance again).  To disabuse both notions, there is no convincing evidence to suggest that exposure to aluminium (in the form of deodorants, antacids, from cookware, etc.) causes Alzheimer's disease, nor is there any evidence to suggest that vaccines cause autism.  I would love to know how these ideas gain such a strong foothold in the public consciousness when you consider the lack of data to support them.  But then it's easy to find websites propounding this nonsense (like this one, which conspicuously lacks any references for the claims being made) then there are movies (like when Ryan Reynolds' character in Smokin' Aces says he doesn't use deodorant because it causes Alzheimer's) and of course, you have celebrities (like Jim Carrey, Jenny McCarthy, and, sadly, Bill Maher) touting these myths as if they should be believed because celebrity somehow qualifies in place of medical expertise or advanced degrees.  Anyway, as for the aluminium and Alzheimer's myth, this one is pretty easy since I will just refer you to the Alzheimer's society webpage on the subject here, and then, as I usually like to do, I will try to boil it down for those of you with short attention spans... 
This particular myth seems to have started in the 1960s and 70s with a handful of studies where researchers gave animals large doses of aluminium phosphate and then, when they looked at their brains, found lots of proteins tangled up like last year's Xmas lights.  These knotted and tangled protein masses looked kinda like the protein tangles that are seen in the brains of Alzheimer's patients (called neurofibrillary tangles) and thus, the idea that aluminium may be linked in some way to Alzheimer's gained some momentum.  However, in the following decades, scientists conducted numerous studies to see if there really was a link.  The vast majority of the studies failed to detect any link between aluminum and Alzheimer's. Those few that have shown causality are almost all in non-human animals and have used doses that are much higher than anything you would come into contact with during your daily routine.  So, unless you plan on drinking solutions or medicines that are loaded with aluminum, or perhaps eating your soda cans after you drink out of them, you should have nothing to worry about.

Saturday, December 26, 2009

A nice resource...

In the rare event that you are as big a nerd as I am, you may find the following site interesting (or, at the very least, very informative):
It is an index of neurological disorders and diseases, from Alzheimer's to Zelwegger's... just click on one (or as many as you want to know about) and you will find a great little summary of the disease and even a summary of how the National Institutes of Health, or more specifically the National Institute of Neurological Disorders and Stroke, is funding research aimed at finding treatments or cures for the various diseases.  Now if only they made a day to day calender, I could have had the perfect Xmas present.

Tuesday, December 22, 2009

A brief introduction to neuroanatomy....

I would like to think that I am equally entertaining when I am giving a lecture... my students would probably disagree. If only I could sing... or dance... or play the tambourine...

Sunday, December 20, 2009

Why do candy canes taste cool?

Candy canes and other mints taste cool because they contain menthol, which can bind to, and activate receptors that normally sense cold.  The fibers at the end of temperature sensitive nerve cells extend to just beneath the surface of your skin, and are also found in your tongue and throughout the inside of your mouth.  At the ends of these cells, there are ion channels which are basically hollow tubes made up of proteins.  At normal temperatures, these tubes are sort of scrunched up so that some of the proteins in the tube block the opening.  At colder temperatures, the tube straightens out and allows ions outside of the nerve cell to pass into the inside of the cell. 

These positively charged ions (sodium and calcium) flood into the cell when the receptors are open, and they change the electric potential across the cell membrane which in turn starts an action potential: a wave of electric current that moves along the length of the nerve cell (I've talked about action potentials and how nerve cells send information before here).  The action potential from a temperature sensitive neuron ultimately sends a signal all the way up to the brain which interprets this signal as cold.  What is interesting about these cold-sensing ion channels is that they can also be opened up when molecules bind to them at sites on the outside of the cell called receptor sites. In the case of our cold receptors, molecules like menthol (which is found in mint leaves, and thus in mint candies like candy canes) bind to the receptor site and cause the protein tube to open up.  This causes the action potentials and signaling we just talked about, which tell your brain that your tongue is cool when really it is just enjoying a candy cane at your normal body temperature.  Interestingly, this is very similar to what happens when you eat spicy foods that taste "hot", except in that case they are different receptors that open when heated (and close when cooled).  These "hot" receptors also open when bound by molecules, in this case, the most prominent one is called capsaicin (which is found in most hot peppers and hot sauces).  So,now you know why candy canes taste cool, and hot sauce tastes hot. (If your holidays are anything like mine, you are probably going to be eating candy canes and Buffalo wings at some point, though hopefully not at the same time).  Happy Holidays!

Wednesday, December 16, 2009

Can sitting too close to the tv make you go blind?

I don't know if I've posted about this one before or not.  If I haven't, I've been meaning to, since this one is an oldie but goodie.  Anyway, the short answer is one we've all suspected since we were little kids, being chastised with this warning by our overprotective parents... sitting too close to the TV will NOT cause you to go blind.  Keeping your eyes too close to your tv screen, however (or your computer screen, or portable media players, video gaming devices, or even books, whatever those are), can cause you to become nearsighted (as the muscles that help your eyes to focus gradually lose their ability to adjust for things that are far away, see here if you don't believe me).  As a corollary to this, a new study shows that Americans are much more likely to be nearsighted today than 40 years ago (here for the journal's webpage).  I knew I should have gone to optometry school!  Maybe I will just buy some stock in Bausch and Lomb.

Are cats smarter than dogs?

So dogs tend to get the bum wrap when it comes to intelligence. Though many dog owners come to appreciate how smart their pets can actually be (our pups know several of their toys by name, and can retrieve them if you ask), most people would probably pick cats as the smarter household pet because they excel at being aloof and even manipulative.  The truth is that there probably is no reliable way to determine which is smarter (especially since there are so many different breeds of dog and cat) and because both are smart in different ways, as they have evolved to be.  Despite the difficulty of the comparison, the New Scientist has an article out now where they have attempted to compare cats and dogs on several different criteria (including brain size, "understanding", "problem solving", and "supersenses").  I don't know how valid the final outcome is (dogs win 6 to 5), but the article is certainly interesting and filled with some good information (like dogs tend to have larger brains, but cats tend to have more cortical neurons, or cats may actually have a better sense of smell than dogs).  The fun facts aside, I have to disagree with some of the categories used (like popularity or eco-friendliness) if the question really is just one of intelligence (rather than the more general question of which one makes the better pet).  Also, I am disappointed to see birds have been excluded from the comparison: despite my dislike for having them as pets, they are certainly smart (like gray parrots for example).  Anyway, the rundown of winners for each category looks like this:
Brain: cats
Shared history with humans: dogs
Bonding: dogs
Popularity: cats
Understanding: dogs
Problem solving: dogs
Vocalization: cats
Tractability (or "trainability"): dogs
Supersenses: cats
Eco-friendliness: cats
Utility: dogs
Totals: DOGS 6, CATS 5

Saturday, December 12, 2009

Does giving your brain a "mental workout" really help ward off dementia?

Well, it is certainly possible, even likely, but not conclusive.  I will refer you to a couple of blogs that have done a much better job of explaining this than I plan to do here...

If you were always the kind of person to read the Cliff's notes, or rent the movie instead of reading the book, the bottom line is that exercise, the real/physical kind, not the mental kind you can do sitting in front of a computer, appears to be the most effective way to improve your overall cognitive function and ward off dementia as you age.  Playing Sudoku or doing crosswords (or other brain games) may have some beneficial effects, particularly if you don't do anything at all to stimulate your brain, but it is more likely that these types of activities will primarily only help you to get better at similar types of puzzles and problems.  So, if you want to do what's best for your brain, you should try to get at least twenty minutes of exercise, several times a week...
you heard me, stop reading this blog and go outside (or, if you live in a frozen part of the country like I do, hit the gym).

Tuesday, December 8, 2009

2009 in Review...weirdness review

Discover magazine has a post about the 15 weirdest science stories of 2009, here
There are many of them I don't think I would characterize as science, but they are still worth checking out.
My favorites are the sea monster and the grad student who became an escort to pay her way through school, (and now has a tv and a book deal). I knew I should have looked at the fine print on those student loans!

Monday, December 7, 2009

It's not exactly brain surgery...

Why should I do all the heavy lifting?

So, I just finished reading the book "Welcome to your brain" by Sandra Aamodt and Sam Wang.  It is a very valiant attempt at covering a lot of different topics in neuroscience and presenting them in a way that is accessible to the general public.  Not only is the book a valiant attempt, but a largely successful one, though there were a couple places in the book where an advanced degree in neuroscience or psychology seemed to be necessary.  BUT, on the whole, most of the chapters are very accessible, and easy to understand, and all the while, the authors do a good job of keeping things interesting, particularly by pointing out popular neuroscience myths.  Anyway, check out the book if you get a chance, and, if not, add their blog (AND THIS ONE!) to your list of blogs you follow, or re-tweet, or whatever the kids are doing these days.  Also, since it will save me from having to write up several posts of my own, here is a link to their article "Six myths about the brain"
If you read this blog, you may find some of it repetitive, but then some of it is stuff I haven't covered (...yet).

Sunday, December 6, 2009

Autism and vaccines...

I am sure you have heard at some point, probably from the mouth of some celebrity (Jim Carrey, Jenny McCarthy, Bill Maher, etc.) that they believe vaccines can cause autism.  I am not going to go on at length about this (I will provide links you can go to for that below).  I will just say a few things.  First, there is no evidence to suggest that vaccines cause autism.  The only reason anyone ever connected the two is because infants usually get vaccines around 10-12 months of age, whereas autism usually gets diagnosed between 12 and 24 months because this is when the child should start developing more social and communicative behaviors (like learning to talk).  Because the one so closely follows the other, people have assumed a connection that simply isn't there, just a coincidence of physical development (an immune system developed enough to get vaccines) and brain development (one developed well enough to start talking).  Second, the scapegoat here, or what tends to get blamed most often is the mercury found in a preservative called thimerosal which used to be used in vaccines.  Almost all vaccines are now thimerosal-free, or as close to it as possible (except for some of the influenza vaccines), yet people still claim that vaccines are causing autism (despite all the evidence that shows that vaccines with thimerosal never caused autism, see below).  Third, some people site the fact that the incidence of autism has increased over the past several decades as evidence of a link since this coincides with increases in both the numbers of children getting vaccines, and the use of thimerosal in those vaccines (since about the 1970s).  Without getting into the whole correlation is not cause argument again (especially since autism can even be correlated to how much it rains) studies have since come out that directly compared the incidence of autism before and after thimerosal was removed from vaccines and showed no differences in the amount of kids being diagnosed with autism (some of the reports are summarized here).  It is also important to note another correlation that coincides with the increased incidence and that is increased awareness and education about autism spectrum disorders (which as a group has grown to include many different disorders in addition to classically defined autism).  This increased awareness has led to many doctors being able to catch or diagnose the disease in more children early on, which in turn would lead to what looks like an increased incidence, but may just be the result of better diagnosticians. Finally, it is understandable that parents of autistic children would want to blame someone or something for their child's disorder.  The reasons for this are many (some even financial like in this case), but mostly because, as a parent of an autistic child, you can often feel helpless to do anything, and frustrated on many levels.  Latching on to a cause (political, if not medical) gives some sense of control and a feeling of being able to work to fix the problem, or prevent it in the future.  This is only natural, and understandable, and these parents do have my sympathy.  HOWEVER, vaccines are CRITICAL to public health, and to individual health.  Very few drugs, if any, have ever had the successes that we see with vaccines (like the almost complete eradication of polio and smallpox for example, which are not completely eradicated because there are still populations of people who do not get vaccinated).  Childhood vaccines are unbelievably important, and will, in many cases, prevent not only several diseases, but DEATH. For example measles kills hundreds of thousands of children in the rest of the world, but not in the US because most kids are vaccinated, and, thanks to a widespread vaccination program in Asia, the number of deaths resulting from measles outside of the US has dropped nearly 80% since 2000.  If you are a parent, don't let unreasoned and unsubstantiated fears prevent you from keeping your child ALIVE and healthy. 
That's pretty much all I have to say on the subject, but, like I said, here are some links for you to check out on your own from some pretty reputable sources, like the FDA, and the American Medical Association (with others in there for good measure).