Anorexia, Dopamine, and Experimental Confounds

We are now continuing on Sci’s new found, somewhat relentless search into the relationship between eating disorders such as binge eating, bulimia, and anorexia, and reward systems that are usually associated with things like drug addiction.
And today I found a human study that looks a little…interesting. For a lot of reasons. Let’s talk dopamine receptors, shall we?
Editor’s Selection IconThis post was chosen as an Editor's Selection for Frank et al. “Increased Dopamine D2/D3 Receptor Binding After Recovery from Anorexia Nervosa Measured by Positron Emission Tomography and [11C]Raclopride” Biological Psychiatry, 2005.
This one’s going to require some background. Let’s talk about dopamine and dopamine receptors.

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Friday Weird Science: The Sunny Sneeze

This time of year is a rough one is the Southeast. It’s a time of angiosperm related hyprocrisy. It’s so pretty outside that it cries out for Easter egg hunts, picnics, and other outside activities.
(it really does look like this)
Unfortunately, once the weather is warm for a few days, it looks like this.
(Sci’s car this morning, only it was worse than that. RUN FOR YOUR LIVES.)
As you might be able to imagine, this sort of thing means that the sneezing rate in the south has a remarkable uptick in the spring (though there’s no data on this, and compared to fall and summer allergies and winter colds, Sci might indeed just be spouting off lies right now).
But did you know that there are some people who will sneeze on a bright, sunny day, regardless of the pollen count? Did you know WHY?! Langer et al. “When the Sun Prickles Your Nose: An EEG Study Identifying Neural Bases of Photic Sneezing” PLoS ONE, 2010.
And the best part of this study, what do you CALL the “photic sneeze reflex”?
ACHOO (Autosomal Cholinergic Helio-Ophtalmologic Outburst) syndrome. Some grad students who came up with this were probably giggling hysterically over their beers for this one.
(Sci would like to note that she sneezed no less than about 5 times during this write-up, though probably not due to sunlight)

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HM Brain Slicing: So much better than TV

In case any of you peeps have missed it (and you never know), the great memory patient, HM, died last year on Dec 2, 2008.
HM was an epilepsy patient who suffered horrible seizures from age 16 on. Finally, we was referred to a neurosurgeon, who localized the seizures to the medial temporal lobes, and he had them removed in 1953. The good news: new epilepsy. The bad news: no MEMORY. HM retained all of the memories from before the surgery, but until the day of his death, was unable to create new ones. He continually thought it was 1953. He was capable of doing things requiring short term memory and retained an IQ of 112, but could not remember anything new taught to him. Interestingly, he could retain motor memories, and could learn new motor procedures and remember them, though he didn’t remember learning them. HM was altogether a fascinating patient, and taught neuroscientists a huge amount about the brain. Unfortunately, due to his severe amnesia, he lived the rest of his life in a care institute, dying peacefully in 2008.
Though obviously informed consent was a little difficult, every time they asked, HM agreed to donate his brain to science, and the person with his power of attorney also agreed. Thus HM’s brain is currently being SLICED into 70um (those are microns, very small) thick sections, in the hopes that we will be able to gain even more knowledge about the man and his brain following death. You can follow the slicing, which is going to take 50 hours, here and here. They’re about to reach the temporal lobes, and there it should get very exciting! It’s a big moment for neuroscience.
Sci is totally geeking out about this, and she and her charming co-blogger Evil Monkey have been tweeting it up over the past few hours (Evil is @neurotopia, and you should follow him on twitter). Some of the people Sci has talked to have expressed reservations about having their brains (or bodies) sliced on live video feed. Sci personally thinks she wouldn’t mind at all, if it was for scientific benefit. Also, I have been told I have a very pretty brain. But she would be interested to hear the thoughts of others. Would you donate your brain to science? Would you mind being sliced (after death) on live video? Why or why not?

Mapping the Glutamate Receptor

So Sci said she wasn’t going to blog this week because of Open Lab and how stressed she is.
(Sci right now, only with better hair and no pocket-protector)
But she lied.
The science, it calls us, precious.
Ah, the power of Twitter. It is indeed powerful, for it hath informed Sci of a new development in SCIENCE. Also, it made her sing. We’ll get to that. Sobolevsky, Rosconi, Gouaux “X-ray structure, symmetry and mechanism of an AMPA-subtype glutamate receptor” Nature, 2009.
glutamate receptor.jpg
Pretty, huh?

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Oxytocin: Starting with the basics

So sometimes, Sci gets questions, and sometimes those questions…are close enough to requests. And so, today Sci will begin what is probably going to be an extensive basic series on oxytocin. We ALL love oxytocin, right? Right! And we all missed Sci’s big honkin’ basic science posts right? Of course right!
So the question basically came down to this: What are the effects of oxytocin in female vs males, in particular the effects on sexual and bonding behavior, and how does this influence the autonomy of people (eg, are we really the tools of our hormones). The short answer: yes and no. The long answer: is very long. So today Sci is going to begin with a background post on oxytocin, what it is, where it acts, and some basic functions. The next post will be on effects of ocytocin in females specifically, and then a post on ocytocin in males specifically. And then, the synthesis. And interspersed in there, a few Friday Weird Sciences. I mean, oxytocin makes for some GREAT weird science. :) Keep in mind, though, that although Sci has done a boatload of research getting ready to blog this topic, she by no means going to hit ALL of EVERYTHING. She might have to blog some specific papers in the future, and she definitely welcomes anyone willing to chime in the comments with more info!
So here we go.
(Complicated molecule, complicated actions)

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SFN Neuroblogging: Got Type 2 Diabetes on the Brain

As some of my readers from WAY back (all two of you, hi guys!) may know, diabetes is one of Sci’s favorite things. It’s one of those things that, if she could start her entire little sciency life over, would be something she would heavily consider as a focus. Heck, there’s always another post-doc, right?
Anyway, you might think that diabetes would not be one of the things generally discussed at Society for Neuroscience meetings. But you would be wrong. The symptoms of diabetes, type I or II, stem from not enough insulin, whether that is because you don’t produce any (type I) or you don’t have enough and aren’t sensitive enough to what you have (type II). Insulin isn’t just limited to the gut, pancreas, and muscles, however. It’s also important in the brain. Normally, your brain is pretty responsive to blood levels of glucose, no matter what, because you want your brain to be the last thing to go when your blood sugar levels drop. But insulin still plays an important role, and insensitivity to insulin, like that seen with type II diabetes extends to the brain as well.
This study taught Sci a lot of things that she didn’t necessarily know. First, it taught her that insulin sensitivity is affected by free fatty acid levels. And it taught her that both of these together could have major effects on cognitive impairment. Suddenly the major increases in type II diabetes are looking a little more scary.
V. E. COTERO, E. C. MCNAY “Effect of intrahippocampal FAs with varied saturations on spatial memory in adult Sprague-Dawley rats”
Doesn’t sound like anything to do with type II diabetes, does it? You would be surprised. :)

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SFN Neuroblogging: The paralyzing effects of CO2

Sci is back from SFN, but she is by no means done with the neuroblogging! Unfortunately, due to a crazy schedule and spotty wireless, Sci was not able to get as much neuroblogging in as she wanted. So she’s going to continue for a few more days, with some of the coolest things she saw at this year’s conference.
For this post, we’re going to basic principles, made extra cool by two things: crayfish and videos!
Univ. Kentucky, Lexington, KY
Synaptic mechanisms underlying carbon dioxide’s induced paralysis

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Some more questions on Ritalin

Sci got this comment to her Ritalin post the other day:

It sounds like you are suggesting that cocaine taken in the same form as Ritalin — as low-dose, slow release pills — would produce the same effects as the ADHD medication does. But, clearly, the FDA has seen fit to outlaw cocaine and place its seal of approval on doctor-prescribed Ritalin. Not that I think the FDA is infallible or anything, but did they really make the mistake of controlling one substance and permitting another that are essentially equivalents? Benzoylmethylecgonine and methylphenidate are clearly not the same chemical compounds, but if they act in synonymous ways on the brain, shouldn’t they be treated equally under the law?
And what about the all-touted maxim that patients who have not been prescribed Ritalin should not take it but those who have been shouldn’t miss a dose? Is there really such a neurological difference between those with ADHD and those who haven’t been diagnosed with it, or is it just a matter of how much rapport you establish with your psychiatrist? (I am not trying to patronize; I legitimately want to know!)
Similarly, are their patients for whom controlled doses of cocaine would yield medical benefits equal to or exceeding those of Ritalin? Or are there manifold side effects that discourage the use of cocaine as an ADHD/ concentration medication in spite of its similarities to Ritalin?
Personally, I’m skeptical of many of the diagnoses of ADHD that I see and of the politician-worthy campaigns that I hear that deny the efficacy of Ritalin for patients who have not been diagnosed with ADHD. It seems to me that for a disorder whose diagnosis is so imprecise and objective, it’s a convenient coincidence that most takers of Ritalin who have been diagnosed with ADHD (regardless of whether or not the diagnosis is accurate) show marked improvement in concentration…

As you can see, it’s long and has a lot of questions. And some of them are very good ones. But I knew that answering it within the comment thread was going to be long, and also I needed to use lots of links. So congrats, cerebration! You’re getting your very own post!!!
Here we go.

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Ask Scicurious: Agomelatine

Sci feels really famous today! That’s because someone actually emailed her to ask her a question!!!! This makes her feel very knowledgeable and wise, even though she had no idea what the person was asking and had to look it up. Anyway, here goes nothing, your very first Ask Scicurious!

t’s me, Juniper. I hope I’m not bothering you.
I would like to please pester you with some questions. In your opinion, is agomelatine as good as it sounds? What about for patients who once responded to NDRIs but no longer do? (Does that last question even make any sense?)
I thought you might be a good person to ask because of your dopamine obsession. :) I found this because I was researching antidepressants to ask my doctor about. It was particularly interesting to me because bupropion is particularly interesting to me. I am always more than willing to read and try to understand PubMed articles, but I don’t have access to the ones about agomelatine. Besides, I really want to know what you personally think.
Just so you know, I’m only asking you out of curiosity. I wouldn’t ever ask anyone but my doctor for medical advice, and you can’t even get this drug in the States anyway. Also: I totally understand if you are way too busy to address my silly questions.
P.S. Objectively, 10 Things I Hate About You is a really bad film. I only think it’s cute because I’m old and nostalgic and I was a teenager in the ’90s.

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Making a Long-Term Memory? Don’t Forget to Tag it!

I’m sure you all know that you have both a short-term and a long-term memory. Many people think of those as separate things, and to us, it may seem that way. But in fact, the formation of short and long term memories in the brain is very intertwined, and a short-term memory can become a long-term one. What we don’t really know is HOW this happens. What makes the difference between remembering a phone number for a few minutes and remembering it for months? Turns out, it’s a simple tag. Ballarini et al. “Behavioral tagging is a general mechanism of long-term memory formation.” PNAS, 2009.

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