Sci is at SciAm blogs today, looking at another OCD study (the second in two weeks!). This one is looking at how optogenetics can break a repetitive habit. What does it mean? What is the circuit? Head over and check it out!
Archive for the 'Behavioral Neuro' category
Obesity and OCD: 1+1 = 0
What do the overconsumption of food and Obsessive-Compulsive Disorder (OCD) have in common? At first, this sounds like a trick question. But deep in the brain, the molecules underlying our behavior may come together for these two conditions.
The first is MC4R, a receptor for melanocortin. It binds hormones and affects feeding behavior, mutations in MC4R are associated with severe overcomsumption of high fat, high calorie foods and with obesity. A mouse without an MC4R gene will become severely obese compared to its wildtype counterparts.
SAPAP3 is a protein that is associated with synapses, the spaces between neurons. It can regulate things like receptor levels that determine how well a neuron responds to excitatory input. But a knockout of SAPAP3 in mice produces something very different: severe overgrooming, a model of OCD. All rodents groom themselves, it's necessary to keep clean. But SAPAP3 knockouts groom themselves far, far too much, to the point of creating terrible lesions on their skin. This has been proposed as a model of OCD, as many people with OCD become obsessed with cleanliness, and will do things like, say, washing their hands, to the point of severely damaging their skin.
So a knockout of MC4R creates obese mice. A knockout of SAPAP3 creates overgrooming mice. You might think that if you combined the two knockouts, you would get severely obese mice that also overgroomed.
But you don't. Instead, you get mice that, to all appearances, seem completely normal. No obesity. No overgrooming.
What gives?
Xu et al. "Double deletion of melanocortin 4 receptors and SAPAP3 corrects compulsive behavior and obesity in mice" PNAS, 2013.
(Warning: there is a figure below of an over groomed mouse. It's not a pretty picture)
Fighting stress with adenosine antagonists
Sci is at SciAm Blogs today, covering a study that combats the effects of early life stress using adenosine 2A antagonists. Why did this study catch my eye? Caffeine is an adenosine 2A antagonist...head over and check it out.
Music Training and a Sensitive Period
I started piano lessons when I was 4-5 years old. I remember years of piano teachers, forced half hours on the piano, and kicking around my piano teacher's house waiting for my brother to finish his half hour. By the time I entered middle school and took up band instead, we kids were able to successfully petition to be let off the piano lessons. I wish to this day that I was a better pianist, but I definitely don't miss the practicing.
But I've wondered if they did me some good. After I stopped the piano, I picked up the clarinet. And I was pretty good at it. Then I started singing, and I turned out to be a decently talented singer. Now, I'm no pro, but I think I pass for an ok amateur. For some of this, I know I had a leg up, after all, I could read sheet music and didn't have to be taught from day one (thank you, piano teachers!).
But what if it was more than just being able to tell a treble from a bass clef? What if the early music training made a deep impression on my brain?
Steele et al. "EarlyMusical Training andWhite-Matter Plasticity in the
Corpus Callosum: Evidence for a Sensitive Period" Journal of Neuroscience, 2013.
The effectiveness of ECT: 5-HT1A receptors
Sci is at SciAm Blogs today, wondering why ECT works to treat depression. The truth is, we still don't know. But today's study is looking at 5-HT1A receptors, and what role they have to play. Head over and check it out.
Treating Depression with Ketamine
Sci is at SciAm today, where a recent piece was discussing ketamine. While ketamine's been getting some big press, many people assume that we don't know how it works. And while we don't KNOW...we do have some ideas. I'm talking about one of them. Head over and check it out.
The scent of a kitten: Fear may smell like cats, if you're a mouse
What does terror smell like? Well, if you're a mouse, terror smells like something that's going to eat you. Maybe a cat, a fox, or a large bird. As prey animals, mice need all the help they can get in avoiding potential predators. And they get a lot of help from smell. Most predators produce pheromones that mice can sense, and these are often the only warning the mouse has that it's about to become dinner.
But not all dangers produce pheromones, and mice still have to let each other know that something is coming. So, as these authors show, mice may produce pheromones of their own that can communicate alarm to other mice.
If you need to keep the mice away, be prepared to wear...ear d'terror.
Brechbuhl et al. "Mouse alarm pheromone shares structural similarity
with predator scents" PNAS, 2013.
(Or get a cat. That works too. Behold, Scicat).
Becoming an individual twin
Sci is at SciAm Blogs today, talking about a study showing development of individuality in genetically identical mice. It's not the genetics, and it's not the environment. Rather, it's how you experience your environment that makes an individual difference. Head over and check it out!
(Source)
The Squeaky Wheel Gets the Grease
Everyone knows that the squeaky wheel gets the grease. After all, in a crowded room, it's often the loudest voice that's going to get heard. And if you're a busy rat mom just trying to get through the day, well, when all your pups are squeaking? Start with the one that squeaks the loudest!
But who DOES squeak the loudest, and what does that do?
(So cute! Source)
Bowers et al. "Foxp2 Mediates Sex Differences in Ultrasonic Vocalization by Rat Pups and Directs Order of Maternal Retrieval" Journal of Neuroscience, 2013.
Growing old with NF-kB
Sci is at SciAm blogs today talking about a new study on aging. Specifically, the discovery of a new role for the protein NF-kB. Less NF-kB? Longer lived mice. What does this mean and where does it go? Head over and check it out.
