If you love dogs, this will put a smile on your face.
If you love dogs, this will put a smile on your face.
Also, you live on one planet next to one star among a galaxy filled with upwards of 300,000,000,000 stars, in a universe with 300,000,000,000 galaxies, each galaxy in turn filled with hundreds of millions to hundreds of billions of stars. You share fifty percent of your DNA with a banana. You are more closely related to chimpanzees than mice are to rats. You are directly related to every single living organism on this planet. You are, in fact, related to every non-living entity as well (including the device you’re using to read this) because all of our elements were forged together inside the hearts of dying stars. Everything you see in the universe has evolved from a point of infinite mass and density, to quark-gluon plasma, to hydrogen atoms, to complex elements, to you! But all of that stuff we can interact with only makes up 5% of the matter in the universe. The rest is dark matter and dark energy, which we can’t see, hear, touch, smell, or taste. You wouldn’t be here today if you didn’t have an unbroken lineage of survival tracing back to the beginning of life on this planet. That means not a single one of your direct ancestors, stretching back over three thousand million years, has ever died before successfully reproducing—this occurring on a planet where over 99% of all species that have existed are currently extinct. Survival is the exception, extinction the rule. Yet here you are. You are also constantly replacing the cells in your body, so much so that in 7-10 years not a single cell in your body will be the same as today. You are, down to every last atom, a different person than you were when you were born. Yet your brain still manages to be ‘you’, day after day, year after year. All the solid material around you is not only 99.9999999999999999% empty space on the quantum level, it’s also in a constant state of dynamic agitation. All of your atoms are dancing, jiggling waves and particles, existing not as individual entities, but only as probabilities. Put enough of them together, though, and we get the world as we know it.
Neuroscience research got a huge boost last week with news of Professor John O’Keefe’s Nobel prize for work on the “brain’s internal GPS system”. It is an exciting new part of the giant jigsaw puzzle of our brain and how it functions. But how does cutting-edge neuroscience research translate into practical advice about how to pass exams, remember names, tot up household bills and find where the hell you left the car in a crowded car park?
O’Keefe’s prize was awarded jointly with Norwegian husband and wife team Edvard and May-Britt Moser for their discovery of “place and grid cells” that allow rats to chart where they are. When rats run through a new environment, these cells show increased activity. The same activity happens much faster while the rats are asleep, as they replay the new route.
We already knew that the part of the brain known as the hippocampus was involved in spatial awareness in birds and mammals, and this latest work on place cells sheds more light on how we know where we are and where we’re going. In 2000, researchers at University College London led by Dr Eleanor Maguire showed that London taxi drivers develop a pumped-up hippocampus after years of doing the knowledge and navigating the backstreets of the city. MRI scans showed that cabbies start off with bigger hippocampuses than average, and that the area gets bigger the longer they do the job. As driver David Cohen said at the time to BBC News: “I never noticed part of my brain growing – it makes you wonder what happened to the rest of it!”
Yet great breakthroughs don’t automatically translate into practical benefits. “Research may give us great insights, but we still can’t cure Alzheimer’s,” points out neuroscientist Baroness Susan Greenfield. “And just because we know more about what parts of the brain do normally, it doesn’t tell us why things go wrong. We still need to know why special cells die in dementia. How come you can have a major stroke with lots of neuronal damage, but not lose your memory? What is the link between Parkinson’s disease and dementia?” In other words, why are some cells damaged but not others?
Lab-based research is key to piecing together the jigsaw of how our brains work and what goes wrong when they don’t. Even scans or postmortem examinations of brains of people who had dementia are of limited value, points out Greenfied, because “degeneration starts 10-20 years before symptoms appear”. So what does neuroscience tell us about keeping the brain fit?
Use it or lose it
It seems obvious that the more you train, use and test your brain, the better it will perform. There is some evidence that people with more education or skills have a lower incidence of dementia. But the picture is complicated; perhaps highly educated people eat better food. And more skilled people may be more likely to be in work, benefiting from exercise, social interaction and mental stimulation. You may build up a “cognitive reserve” while young, which gives you a headstart over less educated people once dementia sets in. Staying physically, mentally and socially active means that even if your brain scan looks as ropey as that of a less active person, you will function better. No one can confirm the benefits, but there is at least no downside to daily sudoku, crosswords, reading, walks and talks.
Nootropics are also called smart drugs or cognitive enhancers. One of the best known is modafinil, a “wakefulness-promoting” drug that stimulates the central nervous system and is only prescribable in the UK for excessive daytime sleepiness (narcolepsy). Whether it is much more effective than a strong cup of coffee remains debatable, but its effect lasts longer. Modafinil is widely used by academics and students because it makes people feel sharper and more alert. Professor Barbara Sahakian of the University of Cambridge has found that sleep-deprived surgeons perform better on modafinil, and thinks it may have a wider role in improving our memory and mental function. “We found that modafinil improves motivation and working memory in healthy people and makes doing tasks more pleasurable,” she said. But long-term safety, especially for young brains, is still not established. But for a lot of students, the question isn’t whether the drugs are safe or constitute cheating, but how they can get hold of some.
Our environment is full of neurotoxins that can interfere with the genes, proteins and small molecules that build and maintain our brains. The younger the brain, the more susceptible it is to neurotoxins. A paper by the US National Scientific Council on the Developing Child says there are three types of neurotoxins that can affect the developing brain: environmental chemicals such as lead, mercury and organophosphates (pesticides); recreational drugs such as alcohol, nicotine and cocaine; and prescription medications such as Roaccutane, used for severe acne. Mature brains can be quite resilient, thanks in part to a barrier of cells that restricts entry of chemicals from the bloodstream into the brain tissue. But drugs, alcohol and cigarettes will poison even the most developed of brains if you take enough of them.
Keep the blood flowing
The brain needs a good blood flow to deliver vital nutrients and oxygen and take away waste products. Smoking, high blood pressure, uncontrolled diabetes, obesity and high cholesterol all sludge up the arteries and impede blood flow. If you care about your brain function, sorting out these risk factors remains the most useful thing you can do.
Effects of diet
Omega-3 fatty acids, antioxidants such as vitamins C and E, and vitamins B and D all have neuroprotective effects, but trials have failed to show that high-dose supplements of these individual nutrients will protect you from dementia. However, eating a tasty Mediterranean diet that combines most of these nutrients can’t hurt.
Professor Sahakian has identified five areas of neuroscience research that will help our understanding over the next five years.
• Smart and wearable technology to monitor people’s brain health – similar to wristband monitors that track heart rate.
• Brain scanning to monitor changes in mental illness and track changes during treatments such as CBT.
• Trials of neuroprotective drugs such as solanezumab to prevent further deterioration in patients with Alzheimer’s disease.
• Connectomics, the study and production of connectomes – neural maps of the brain – will combine a number of techniques to map and study connectivity in the brain.
• Genetics, to understand the genetic mutations that contribute to autism and other conditions.
• This article was amended on 13 October 2014. An earlier version referred to Edvard and May-Britt Moser as Swedish rather than Norwegian.
Oxytocin has been called the “love hormone” because it plays an important role in social behaviors, such as maternal care and pair bonding. In a study published by Cell Press on October 9th in the journal Cell, researchers uncover oxytocin-responsive brain cells that are necessary for female social interest in male mice during estrus — the sexually receptive phase of their cycle. These neurons, found in the prefrontal cortex, may play a role in other oxytocin-related social behaviors such as intimacy, love, or mother-child bonding.
"Our findings suggest that social interactions that stimulate oxytocin production will recruit this newly identified circuit to help coordinate the complex behavioral responses elicited by changing social situations in all mammals, including humans," says senior study author Nathaniel Heintz of The Rockefeller University. "Future investigation of the exact mechanisms responsible for activation of this interesting circuit may provide insights into autism spectrum disorder and other social behavioral disorders."
Oxytocin-responsive neurons are found in many brain structures, highlighting the importance of the hormone for a variety of social behaviors. But it is not clear which cells are targeted by oxytocin, or how the hormone affects neural circuits. One potential clue came when lead study author Miho Nakajima of The Rockefeller University discovered a population of neurons in the medial prefrontal cortex that express the oxytocin receptor. When the researchers disrupted the activity of these neurons, female mice lost interest in male mice during estrus and spent about the same amount of time with them as with a plastic Lego block. By contrast, these females retained a normal level of social interest in other females during estrus, and in male mice when not in estrus. Moreover, the social behavior of male mice was unaffected by the silencing of these neurons.
Taken together, the findings show that the new class of oxytocin-responsive neurons regulates an important aspect of female social behavior in mice. “Our work highlights the importance of the prefrontal cortex in social and sexual behaviors and suggests that this critical cell population may mediate other aspects of behavior in response to the elevated oxytocin levels that occur in a variety of different contexts,” Heintz says.
Journal Reference: Miho Nakajima, Andreas Görlich, Nathaniel Heintz. Oxytocin Modulates Female Sociosexual Behavior through a Specific Class of Prefrontal Cortical Interneurons. Cell, 2014; 159 (2): 295 DOI: 10.1016/j.cell.2014.09.020
London Space | (by Marc Khachfe)
Autism as a Disorder of Prediction
Read the full article Autism as a Disorder of Prediction at NeuroscienceNews.com.
Researchers suggest autism stems from a reduced ability to make predictions, leading to anxiety.
The research is in PNAS. (full open access)
Research: “Autism as a disorder of prediction” by Pawan Sinha, Margaret M. Kjelgaard, Tapan K. Gandhi, Kleovoulos Tsourides, Annie L. Cardinaux, Dimitrios Pantazis, Sidney P. Diamond, and Richard M. Held in PNAS. doi:10.1073/pnas.1416797111
Image: Impaired prediction skills would also help to explain why autistic children are often hypersensitive to sensory stimuli. Most people are able to become used to ongoing sensory stimuli such as background noises, because they can predict that the noise or other stimulus will probably continue, but autistic children have much more trouble habituating. Credit Jose-Luis Olivares/MIT.
THEORIES OF MOTIVATION!