The Elderly Brain
Sam Wang is an associate professor, Department of Molecular Biology and the Princeton Neuroscience Institute.
Wang grew up in California and studied physics at the California Institute of Technology. Seeking his Ph.D. at Stanford University, he switched to neuroscience. He has worked at Duke University as a postdoctoral fellow and aided political leaders as a Congressional Science Fellow. After completing his postdoctoral studies, he spent two years at Bell Laboratories in Murray Hill, N.J., where he learned to use pulsed lasers to study brain signaling before coming to Princeton.
Wang, who has published more than 40 articles on the brain in leading scientific journals. His educational reach extends past the laboratory and classroom in his books, popular articles and efforts to convey neuroscience to interested nonscientists.
Question: Do brain gyms work?
Sam Wang: I’ve never been to a brain gym. And I think it will be a fun experience. So brain gyms, obviously, play in a fear that by not being mentally engaged, we will somehow, it’s a use it or lose it kind of thing. And there’s a grain of truth to this, which is that one of the things that you can do to keep your brain happy and functioning well as you get older is to have a mentally engaged lifestyle. So the number one correlative retained cognitive function as people get older is educational status.
And it’s not clear whether that’s because being educated gives you the tools to lead a more engaged life or whether, maybe, if you’re mentally engaged person, you might be the kind of person who would go to college and graduate schools. It’s a chick and egg problem.
But in either case, that’s the number one correlate. In general, individual tasks that you learn when you play brain games, you go to brain gyms tend to only increase your capacity at that particular task or task of that type and they tend to lead to small benefits. And so, I think a lot of these exercises don’t lead to large benefits.
Now, it could be that doing a lot of these different things is something like a full body workout, then it could be that there’s some moderate benefit. But I think the people who go to those should really remember not only the intellectual principle, right, a sound mind but also the sound body principle. And so, I think any such gym should include what we talked about earlier, fitness training.
Question: How do brains decline?
Sam Wang: So there’re different kinds of cognitive memory loss that occur with aging. Certain kinds of memory loss such as forgetting where your car keys are part of the normal process of getting older. In fact, memory peak surprisingly early at the age of 30 and then declines gradually with time. So forgetting where your keys are is not a cause of particular concern.
Then, there’s dementia, which is forgetting, say, that you, like the old saying goes that if you forget where your glasses are, that’s normal memory loss. If you forget the fact that you wear glasses, that’s dementia.
So just normal memory loss is not a cause of concern. It’s not well-understood exactly what physically underlies this, although plausible candidates are loss of the brain’s ability to form new connections or to easily modulate the weight of the connections between nerve cells, those are called synaptic weights.
And so, those will be the candidates for why the brain seems to be less plastic in certain ways as we get older. But it’s not super well-understood. Now, there’s another category of memory loss. The severe decline in the form of dementia. And the thing that’s understood there is that you can look in the brains of people who after death or diagnosed as having Alzheimer’s disease and they have plaques and tangles that appear to be either the causes of cell death or perhaps the residue, the aftermath of cell death. And these plaques and tangles seem to be at the root of certain kinds of cognitive loss. And that’s something that’s studied now. And it’s a pretty active area of research.
And the current goal is to try to find ways to [stay off] those cognitive losses by even a few years. Because as we live longer, having a few years becomes very important.
Sam Wang says a mentally engaged lifestyle is the best training for the brain.
If you want to know what makes a Canadian lynx a Canadian lynx a team of DNA sequencers has figured that out.
- A team at UMass Amherst recently sequenced the genome of the Canadian lynx.
- It's part of a project intending to sequence the genome of every vertebrate in the world.
- Conservationists interested in the Canadian lynx have a new tool to work with.
If you want to know what makes a Canadian lynx a Canadian lynx, I can now—as of this month—point you directly to the DNA of a Canadian lynx, and say, "That's what makes a lynx a lynx." The genome was sequenced by a team at UMass Amherst, and it's one of 15 animals whose genomes have been sequenced by the Vertebrate Genomes Project, whose stated goal is to sequence the genome of all 66,000 vertebrate species in the world.
Sequencing the genome of a particular species of an animal is important in terms of preserving genetic diversity. Future generations don't necessarily have to worry about our memory of the Canadian Lynx warping the way hearsay warped perception a long time ago.
Artwork: Guillaume le Clerc / Wikimedia Commons
13th-century fantastical depiction of an elephant.
It is easy to see how one can look at 66,000 genomic sequences stored away as being the analogous equivalent of the Svalbard Global Seed Vault. It is a potential tool for future conservationists.
But what are the practicalities of sequencing the genome of a lynx beyond engaging with broad bioethical questions? As the animal's habitat shrinks and Earth warms, the Canadian lynx is demonstrating less genetic diversity. Cross-breeding with bobcats in some portions of the lynx's habitat also represents a challenge to the lynx's genetic makeup. The two themselves are also linked: warming climates could drive Canadian lynxes to cross-breed with bobcats.
John Organ, chief of the U.S. Geological Survey's Cooperative Fish and Wildlife units, said to MassLive that the results of the sequencing "can help us look at land conservation strategies to help maintain lynx on the landscape."
What does DNA have to do with land conservation strategies? Consider the fact that the food found in a landscape, the toxins found in a landscape, or the exposure to drugs can have an impact on genetic activity. That potential change can be transmitted down the generative line. If you know exactly how a lynx's DNA is impacted by something, then the environment they occupy can be fine-tuned to meet the needs of the lynx and any other creature that happens to inhabit that particular portion of the earth.
Given that the Trump administration is considering withdrawing protection for the Canadian lynx, a move that caught scientists by surprise, it is worth having as much information on hand as possible for those who have an interest in preserving the health of this creature—all the way down to the building blocks of a lynx's life.
The exploding popularity of the keto diet puts a less used veggie into the spotlight.
- The cauliflower is a vegetable of choice if you're on the keto diet.
- The plant is low in carbs and can replace potatoes, rice and pasta.
- It can be eaten both raw and cooked for different benefits.
Great again? Why America stopped looking forward to the future
- Income inequality is dividing Americans.
- Wages haven't risen in 30 years, while prices for housing, schools, and basic goods has.
- Canny (and uncanny) politicians have learned how to milk the politics of fear by comparing the present to the past.
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