Archive for the 'Addiction' category
Sci DID post yesterday, hurricane or no hurricane (The Sci-household is intact and unscathed). I was at SciAm, talking about an fMRI study looking at alcoholism and social exclusion. While alcoholics and controls behaviorally report similar social exclusion, their brains do very different things. A study like this might be helpful to evaluate whether therapeutic interventions targeting social exclusion are really helping the way alcoholics respond. Head over and check it out.
Nature Reviews Neuroscience came out with a perspectives article today on overeating and obesity, and the evidence behind the food addiction model that is gaining popularity. It's an issue that I myself have given a lot of thought to: is there REALLY such a thing as food addiction that's just like heroin addiction or cocaine addiction? And if there is...what IS it? What are the criteria?
Ziauddeen et al. "Obesity and the brain: how convincing is the addiction model?" Nature Reviews Neuroscience, 2012.
(I suppose I could insert the mainstream media obligatory demeaning headless photo of an overweight person here. But you know what? It's demeaning. Source
EDITED: I have now replaced the sloth picture. I thought sloths were just adorable, and it didn't even occur to me that some people might interpret a baby sloth as "slothful" or "laziness" in this context. I really didn't mean that. Just wanted adorable. This kitten will do instead. Sorry, I really didn't mean to be offensive!)
Sci's been meaning to cover this paper for a while, honestly. There is really so much to blog and so little time, you know? I saw this paper make a minor splash when it came out back in June, and I've been wanting to read it myself. And what better way to really READ a paper than to blog it?
So let me introduce the subject of today's paper, the monogamous prairie vole.
The prairie vole is kind of a darling of the research vole. I mean, it's got nothing on mus musculus, but we do tend to like our voles. They're monogamous! Isn't that sweet! It's cute and easy to breed, and...monogamous! Really, that's the defining feature that makes them interesting, because there really are relatively few species out there other than primates that ARE monogamous. Only 3% of mammals, in fact. So some research has gone in to what it is that MAKES them monogamous, especially when compared to their extremely close cousins the mountain voles.
And then of course, once you've got through all the monogamy issues with the oxytocin and the vasopressin, you start to look at other aspects of this rare kind of social behavior. Things that can be affected by it and things that can affect it.
Things like drugs.
Liu et al. "Social Bonding Decreases the Rewarding Properties of Amphetamine through a Dopamine D1 Receptor-Mediated Mechanism" J. Neuroscience, 2011.
Sci saw this paper come out last week, it made it big in the mainstream media, and a couple of blogs covered it. Whenever something like this comes up in the news, I just have to get the paper myself and make sure whether it's all really true. And now I have it, so here we go.
Wagner, et al. "Spontaneous Action Representation in Smokers when Watching Movie Characters Smoke". The Journal of Neuroscience, 2010.
(And a tribute to my personal goddess of awesome, Christina Hendricks. Source)
Every so often, Sci comes across a study that at first looks incredibly exciting...and then kind of becomes a bit of a let down. Not because it was a BAD study, mind, but because I want MORE. Thus was this study.
So let's talk about high fat diets, and let's talk about coke. But mostly coke.
The short answer from my reviewing of the literature? Not much. And it had so much POTENTIAL!
Dangit that's like blowing the punchline before I tell the joke. I must be becoming my mother...
So. I'd like to start this post out with a shout out to the last author (last author on a paper is traditionally the most badass position), Dr. Nora Volkow.
Dr. Volkow is the current head of the National Institute on Drug Abuse, part of the National Institute of Health. She's a masterful researcher, a great administrator, and one heck of a brilliant mind (she's also Trotsky's great-granddaughter! The things you learn.). As a woman in science, and a woman in drug abuse research, Sci finds it REALLY amazingly cool to go to a conference, look up at the keynote speaker, and see a woman in one of the most powerful positions in my field, publishing like gangbusters, and generally being awesome. It makes me hopeful and confident that we are getting somewhere, and that someday, I could do the same. You are an Inspiration with a capital I, Dr. Volkow!!
Anyway, back to the subject at hand.
As you might be aware, cocaine is a stimulant. Interestingly, Ritalin (the chemical name is methylphenidate) is ALSO a stimulant, just longer acting (and much lower dosing when given as a pill). Given that we have been able to successfully treat opiate addictions like heroin with similar, but longer acting drugs like methadone, scientists have been very curious if it would be possible to treat cocaine addiction like we treat heroin addiction, only instead of using methadone, use Ritalin as the replacement. The idea is that Ritalin would stop the craving for cocaine that coke users experience, and so be able to prevent relapse to drug abuse. The more you prevent relapse, the longer that person stays clean, and the better chances they have at staying clean in the long term.
Unfortunately, it didn't work. Ritalin, at the oral doses we usually give for treatment of ADHD and narcolepsy, etc, doesn't appear to do much to affect cocaine craving in humans. Other studies are trying Adderall with a little more success. But in the meantime, the question remains. Can stimulants like Ritalin treat people with cocaine abuse? And what benefits would it have?
Sci would like to note that I'm writing this post while I'm sipping my first cup of coffee for the day. Irony, thy name is caffeine addiction.
So the other day I was out with my running partner, and she mentioned that someone had DIED from caffeine overdose. At first, I thought it must have been a Redbull and vodka thing, but nope. PURE CAFFINE. I got a copy of the article, but then Mo tweeted about it and I knew I had to blog it, at least a little.
First off, that was a really stupid thing to do. But the second question is WHY. A lot of people were very confused. And so I figured, being caffeine's patron saint like I am, I gotta tell you that this stimulant is a double edged sword.
But it's still a lot of fun to wear. And nice to drink. Just...not in insane quantities.
So Sci was sitting in a seminar the other day. We were mentioning this paper, some problems we had with it, some of the things we LIKED about it, and various approaches, etc, in our usual sciencey fashion. As the discussion got intense (in a good way), one of the PIs there leaned over and said to Sci "you know, you should TOTALLY blog about this". Sci paused, and said "well...it's probably a little complicated for my readers".
And it is. The title alone. "Dnmt3a regulated emotional behavior and spine plasticity in the nucleus accumbens"?!?! This is complex stuff, much more complex and involved than I usually cover on the blog. It's got DNA methylation, how that affects things like protein transcription, how that affects BEHAVIOR, and what the heck does all that even have to do with SPINE DENSITY!??! It's a lot. It's complicated to understand, because it involves a LOT of background understanding, and it's complicated to explain, for similar reasons.
But then I thought about it. You know, my readers (all two of you) are some smart people. Many ARE in science, if in different fields, and many are interested in science. You guys can get this just fine, if I can EXPLAIN it. And it's an interesting paper, partially because of what it studies, and partially because of what it REVEALS about what scientists think about "emotional behavior" right now.
So. We're going to break it down. We're going to go through the hefty stuff behind this paper, one chunk at a time. We're going to cover the findings, we're going to cover the ideas, and we're going to cover the problems that the other scientists at the table had with this paper. We're going to go into why the problems with this paper exist, and what can be done about them, and we'll talk about what this means for the field of drug abuse and "emotional" behavior in general. We're going to do it over the next few days. Because y'all are PLENTY smart enough to get this, if you only have the background. And gaining expertise in a field is a lot about being able to know your background, where you came from, interpret it correctly, and move it on to the FUTURE.
Let's do this thing.