What was up in the last two weeks? Bi-weekly neuroscience news

It's time for the bi-weekly news block! This time on the menu: What Instagram does to teenagers' brains, yet another reason to not smoke while pregnant and a new possible explanation of how Alzheimer's comes about.

Image by TomaTheSpook

Image by TomaTheSpook

1. On behalf of your baby's brain: Do not smoke while you're pregnant. 

I guess "don't smoke while pregnant" is not really surprising news per se: We know it can lead to all kinds of fuck-ups for your baby. But recently scientists have added a little more to the pile of bad consequences of this Marlboro Gold. Early nicotine exposure leads to some widespread and long-lasting genetic changes which in turn affect formation and stability of connections between nerve cells long after birth. In simple words: Nicotin before birth = screwed up connections in your brain all the way into adulthood. So, what happens when you connections are impaired this way? The study shows that, as a result of the prenatal nicotine exposure, (mice) babies were more likely to develop ADHD-similar symptoms during their development (and keep them during their adulthood).  However, after the researchers identified and turned off the genetic mechanism that went wrong in the first place, mice became calmer and less distractible! It is pretty exciting to find a direct link between nicotine and gene expression leading to behavioural changes, so yeah! You go, science!

2. Teenage brain and social media

Next time your teenager asks you for twenty Euro (22.43 USD; you're welcome, Americans!) for movies or whatever teenagers are into these days, just press "like" on their Instagram selfie from twenty different accounts and show them how popular they are. According to a new study, a large number of likes on social media activated same regions in the teenagers' brains as eating chocolate or receiving money. Researchers showed the teens different pictures including those submitted by each of them along with the number of likes each pictures received. When the teens saw their own pic being liked by many people their brain activated a region belonging to what is called the "reward system" -- Nucleus Accumbens. Normally, the reward system encourages you to pursue the activities that keep you healthy, well fed, and in top mating form. Basically, it makes us feel good when we engage in behaviours that are necessary for our survival. Apparently, in the age of the social media, internet popularity is essential for our well-being (especially when you're a teenager longing for attention from your peers). I feel you, teenagers: my Nucleus Accumbens lights up every time I have a new subscriber.
Another thing this study found was how influential peer pressure is, even if the peers in question are just virtual strangers. When the teens saw a pic with a large number of likes they were much more likely to like it themselves, thus succumbing to the public opinion. 

Just trying to dilute science stuff with some fun.

Just trying to dilute science stuff with some fun.

3. Could Alzheimer's be just a defence mechanism went wrong?

There are a lot of possible explanations for the Alzheimer's disease and we are not really sure yet of how does it work exactly.  What seems to be indisputable is that amyloid plaques -- blobs of beta-amyloid proteins accumulating in the brains -- found in the patients' brains are a hallmark of this disease. It is believed that they contribute to the degradation of the nerve cells consequently leading to the memory loss and other accompanying problems. 

Alzheimer leads to nerve cell death and tissue degeneration throughout the brain, especially in hippocampus, responsible for the formation of new memories.

Alzheimer leads to nerve cell death and tissue degeneration throughout the brain, especially in hippocampus, responsible for the formation of new memories.

However, a new study published just this week suggests that maybe these beta-amyloid blobs are not the bad guys we are used to see them as. Researchers think that they actually might play a role in fighting infections and, you know, overdoing it a bit. The process might go like this: Normally the blood-brain barrier protects the brain from the pathogens from the blood and does not let them enter the brain. However, as you get older, this barrier begins to leak, so that various viruses and bacteria from the bloodstream enter the brain. And that's where the beta-amyloids go into play. The study indicates that they might be a part of a normal immune response: They build a "cage" around the pathogen and kill it. This was tested in roundworms and mice and we can safely assume that beta-amyloids might play the same role in humans. However,  while defending the brain they might get overwhelmed by the variety of pathogens and overreact, starting the destruction of the neighbouring nerve cells. 
Although very speculative, this study might pave the way for new Alzheimer's treatments. Maybe it will be possible to kill off the bacteria triggering this immune response in the first place, so that the plaques are not even built? Maybe there will be a way to strengthen the blood-brain barrier in aging people and prevent bacteria from reaching the brain? This could change the way we think about Alzheimer's and maybe when we're old it will be prevented with a single vaccine.

Thanks for reading and stay tuned for a report from the Interdisciplinary Conference on Psychedelic Research in Amsterdam where I'm going TODAY and some Brain 101 basics :)

Sources:

1. http://pss.sagepub.com/content/early/2016/05/24/0956797616645673.abstract

2. http://www.nature.com/neuro/journal/vaop/ncurrent/full/nn.4315.html   

3. http://stm.sciencemag.org/content/8/340/340ra72 

Image by Toma