It’s time to take a look at the top stories from this month. I'm joined by Emily Jordan, a PhD student at the Department of Experimental Psychology, Cambridge.
Emily - So, the first paper is very exciting - some scientists at the University of Virginia actually found a way to improve maternal behaviour in mice. Dr. Danielle Stolzenberg could improve behaviour in mouse moms. So, mice usually do have a behaviour after they give birth called retrieval where they carry their pups back to the nest.
Stolzenberg and colleagues wanted to see if they could induce these behaviour in virgin mice who actually hadn’t given birth. So they put a chemical in the drinking water of these mice that would increase histone acetylation and this is the process that increases gene transcription in the brain. The scientists found that the previously non-maternal mice then readily retrieved pups like a good mouse mom would, and then the researchers looked in the brain, in regions that are important for maternal behaviour, and they found that certain genes that are crucial for maternal care were actually upregulated in these mice that had never even given birth.
Hannah - So, they had promoted maternal care in these virgin mice. What are implications of these research? I mean, in what way does it help our understanding of pregnancy perhaps or post-birth care?
Emily - Usually, moms undergo vast array of hormonal changes and if you haven't gone through pregnancy and birth, you as an individual wouldn’t have those hormonal changes, but you can still provide maternal care. So this experiment really looks at particular brain regions and genes that could be affected by experience, such as just being around infants that would also provide the same brain changes that would induce maternal care.
Hannah - And then moving on to the second paper…
Emily - So, the second paper looks at adolescent impulsivity and the brain networks behind impulsivity. It was conducted by a large consortium of researchers who imaged about 2,000 adolescent people, looking at their impulsive behaviour. The study was headed up by Dr. Robert Whelan and Professor Hugh Garavan at the University of Vermont.
What they found was that when they screened a large population of impulsive adolescents, a lot of the impulsive individuals performed exactly the same on a common task of impulsivity. They then wanted to look in the brain to see if there were the same brain networks that work or different brain networks in people who had ADHD (attention deficit hyperactivity disorder) and also, people who had begun initiating drug use at a young age. Because we already know that impulsivity is a common factor in both ADHD and in drug addiction and that stop signal task performance can predict both of these behaviours. It wasn’t known however if the brain mechanisms behind both of these disorders were the same and these researchers actually found that there were two different networks at work.
Hannah - Is this going to be helpful as a diagnostic tool or is it really more getting to grips with an understanding of what's happening in the brain, so the brain correlate for these different behaviours?
Emily - It’s really about understanding the underlying mechanisms behind both addiction and ADHD because the behavioural predictors of both of those disorders are quite similar. All of those people seem to be more impulsive than normal controls and actually, knowing that there are two different patterns of brain activity that could explain these impulsive behaviours might provide novel targets for both drug addiction and ADHD.
Hannah - And moving on to your final paper…
Emily - So, the third paper I found this month looks at social network modulation of reward-related signals. It was published in the Journal of Neuroscience and the work was carried out by a grad student called Dominic Fareri. The researchers asked participants to play a guessing game with a teammate who was either a friend, a stranger or a computer. And during the game, the scientists measured physiological excitement and also, activity in reward areas of the brain. They found that when participants got a correct answer in the guessing game, and were working with a close friend, they showed a greater BOLD response (blood-oxygen-level-dependent level, basically showing how much oxygen is going to different parts of the brain, thereby indicating how active that region is) in the ventral striatum which is an important reward-related area in the brain. And the participants also showed increase skin conductance, indicating physiological excitement. People who had worked with a closer friend reported that their experience had been more positive and rewarding.
Hannah - So, that was showing the scientific data supporting the idea that sharing experiences with close friends makes experiences more rewarding and more enjoyable.
Thanks to Emily Jordan, PhD student at the Department of Experimental Psychology, Cambridge University for her top neuroscience stories of the month.