The Friday Five

In this special edition of Friday Five, we’ve collected 5 of the most popular articles from THE ‘SCOPE for 2014!

5. Is homosexuality "natural"?

4. State Fairs and Stiff Beers: Why We Can't Stop Drinking

3. Is It Really Possible For Someone To Turn Into THE HULK? Don’t Make Me Angry.

2. Science Identifies The Catchiest Songs Ever – Did Your Favorite Make The List?

1. Where Do All Those Leaves Come From?!

Contributed by:  Bill Sullivan

Follow Bill on Twitter: @wjsullivan

Science Identifies The Catchiest Songs Ever – Did Your Favorite Make The List?

Humans have a deeply rooted love for music and rhythm. For reasons we’ve yet to fully understand, certain types of music bring out the warrior inside of us while other types of music are incredibly soothing. Some songs move us to tears, yet others make us angry. And humans are not alone their capacity to respond to music. There is something about these unnaturally occurring sound patterns that speaks (sings?) to all species capable of sensing the reverberations.

Music can hold great power over us. Songs can change moods, spark memories, or inspire greatness. Some of you may have seen the video of Henry, an unresponsive gentleman in a nursing home, spring back to life after hearing his favorite music. Watch this remarkable episode below as neurologist Oliver Sacks explains the phenomenon.

We are also attuned to how divergent musical tastes can be! Teens rarely like the music that their parents listen to and vice versa. David Hasselhoff has an inexplicable legion of devoted fans in Germany. Michael Bolton somehow scored multiple hits despite piercing millions of eardrums. Some only listen to country, rap, rock, or classical, yet some people have promiscuous ears that love it all. And, let’s admit it, jazz is only fun for the musicians playing it.

Germans love the music of David Hasselhof so much that they've placed an eerily realistic wax statue of The Hoff by the Brandenburg Gate.

John Mellencamp once declared that the world is “polluted” with songs. With an estimated 2-5 billion songs having been written throughout human history, it is pretty remarkable for one to gain widespread popularity. The songs that manage to stand out from the crowd are typically called “earworms” because they are so catchy that you can’t shake them out of your head no matter how hard you try. Some of these tunes dig their talons so deeply into your subconscious that it can be agonizing; for example, here’s a list of infectious songs that were actually used to torture people.

Recently, Dr. John Ashley Burgoyne, who calls himself a computational musicologist, used an online game called “Hooked on Music” as a tool to identify some of the catchiest songs humans have ever concocted. Want to know what they are?

Coming in at number 5 is the ABBA hit, “SOS”:

The fourth catchiest song is “Just Dance” by Lady Gaga:

“Eye of the Tiger” by Survivor, the theme from Rocky III, punches in at #3:

One-hit wonder Lou Bega swings in at #2 with “Mambo No.5”:

And the catchiest song ever…(fake electronic drumroll)…“Wannabe” by the Spice Girls:

It should be noted that Burgoyne’s research relied on an internet game to generate the list of catchy songs, so there is inherent bias among the participants. Other research that employed a different algorithm (or should that be “algorhythm”?) have, perhaps thankfully, revealed different results.

All the fun aside, there is a serious element to researching why catchy songs are so easily remembered. The scientists involved with these types of studies hope that their work will reveal news insights into learning and memory, which could potentially be useful in treating conditions such as Alzheimer’s disease.

Contributed by:  Bill Sullivan

Follow Bill on Twitter.

Snowdon CT, & Teie D (2010). Affective responses in tamarins elicited by species-specific music. Biology letters, 6 (1), 30-2 PMID: 19726444

I Am Groot! Plants Are More “Alive” Than We Think

So who saw Guardians of the Galaxy this summer? Awesome, wasn’t it? How could a movie with a talking raccoon and a 1970s-based soundtrack go wrong? Oh, and then there’s Groot, the beloved walking, talking tree-like creature who sprouted the catch phrase, “I AM GROOT!” Until Groot, the only sentient plants children probably knew of were the Evil Trees hurling apples at Dorothy in The Wizard of Oz. But Groot was a “Giving Tree” incarnate.    



Groot shatters the evil living plant stereotype and saves the day in Guardians of the Galaxy.

 

Groot was so endearing, he has given my kids a new reason not to eat their veggies – they don’t like the idea of slaughtering plants. When I reminded the kids that plants are only sentient in the movies, they gave me the look of skepticism. I know it well…I taught it to them. This inspired me to leaf through some botany literature. Much to my surprise, my kids might have a point! Plants are more “alive” than we ever imagined.

Exhibit A.  Plants know when they are being eaten alive! And they fight back…

There is a plant that scientists typically use as a model to study in the lab called Arabidopsis (thale cress, similar to broccoli but tastes even worse). Researchers recently discovered that when they expose these plants to vibrations that mimic those produced by a hungry caterpillar, the plants increase production of glucosinolate and anthocyanin defenses. These are mustard oils that don’t sit well with caterpillars. In other words, the plants can tell when they are being chewed on and release oils to deter the predator.

Another sophisticated defense system used by plants comes from studies on tobacco. When caterpillars attack, these tobacco plants produce “green leaf volatiles”, compounds that act as a distress call by attracting insects that devour caterpillars!

The Hungry Caterpillar: Adorable children's tale or a horror story of gruesome predation?

 

Exhibit B. Plants have a memory and can be trained.

Everyone is familiar with the story of Pavlov’s dog, the famous experiment that demonstrated classical conditioning. Dogs salivate when presented with meat. If you ring a bell before presenting the meat, the dogs become conditioned to salivate at just the sound of a bell. Plants do a similar thing when exposed to light. Researchers have shown that when a plant is exposed to a certain wavelength of light, and then infected with a plant pathogen, the plant “learns” to build up resistance to that pathogen when it “sees” that particular wavelength of light once again. Plants that were infected and then exposed to the light developed no protective response. Plants must possess some sort of biochemical nervous system and memory in order to execute this kind of behavior.

Plants don’t have a brain, but they do behave as if they can think.

 

Exhibit C. Plants protect their young.

Seeds are the equivalent of a plant’s babies and plants have evolved a variety of fascinating ways to take care of their young. Consider serotinous plants, which keep some of their seeds inside the plant body instead of releasing them into the environment where they can be eaten or destroyed by weather. These plants can hold onto their seeds and release them when the time is most favorable for them to survive.

In the 1986 film, “Little Shop of Horrors”, the carnivorous plant Audrey II demonstrated a terrifying new way plants could protect their kin.

 

In another striking example, scientists studying a plant called sea rocket (Cakile edentula) noticed that when grown in a pot with a different member of its species, its roots grew wildly so to soak up more water and nutrients from its competitor. However, if the sea rocket was put into the same pot as its offspring, this competition did not take place!

Still not convinced that plants are more alive than we give them credit for? Check out this video by Michael Pollan.
 

 

While the evidence above isn’t sufficient to conclude that plants on Earth are like Groot, it is clear they are capable of some level of feeling and response. But don’t tell your vegetarian friends…what else would they eat?

Contributed by:  Bill Sullivan

Follow Bill on Twitter.

 

 

Appel HM, & Cocroft RB (2014). Plants respond to leaf vibrations caused by insect herbivore chewing. Oecologia, 175 (4), 1257-66 PMID: 24985883

Allmann, S., & Baldwin, I. (2010). Insects Betray Themselves in Nature to Predators by Rapid Isomerization of Green Leaf Volatiles Science, 329 (5995), 1075-1078 DOI: 10.1126/science.1191634

Karpiński S, & Szechyńska-Hebda M (2010). Secret life of plants: from memory to intelligence. Plant signaling & behavior, 5 (11), 1391-4 PMID: 21051941

Dudley SA, & File AL (2007). Kin recognition in an annual plant. Biology letters, 3 (4), 435-8 PMID: 17567552

The Friday Five

Highlighting some of the coolest science news we’ve seen lately.

1. People living with type I diabetes may have something to celebrate as scientists have successfully used human embryonic stem cells to generate beta cells. These insulin-producing cells could one day be transplanted into humans.

2. How do you ward off the obnoxious guy who won’t leave you alone in a bar? Female squid of the species Doryteuthis opalescens can steer males away by turning on fake testes. Interestingly, when the females turn on the testes, they also get a pay raise at work.

Since human females can’t turn on testes like a squid, a fake moustache might be sufficient to keep unwanted men away.

3. Blinded by the light? Neuroscientists have successfully erased specific memories in mice…using light. But they are not using this knowledge for evil, they used it to demonstrate how different parts of the brain - the hippocampus and cortex - work together to retrieve memories.



Bono remembers everything about the ‘90s because he adequately shielded his eyes from the light.

4. Still “cleaning” your ears with Q-tip swabs? Learn more about your ear wax and why you should not interfere with it.

5. Check out these amazing photos of flowers that look like other things.

A kiss from a rose...

Science quote of the week:

“Science moves with the spirit of an adventure characterized both by youthful arrogance and by the belief that the truth, once found, would be simple as well as pretty.” – James D. Watson

Contributed by:  Bill Sullivan

Follow Bill on Twitter: @wjsullivan

Tanaka, K., Pevzner, A., Hamidi, A., Nakazawa, Y., Graham, J., & Wiltgen, B. (2014). Cortical Representations Are Reinstated by the Hippocampus during Memory Retrieval Neuron DOI: 10.1016/j.neuron.2014.09.037

DeMartini DG, Ghoshal A, Pandolfi E, Weaver AT, Baum M, & Morse DE (2013). Dynamic biophotonics: female squid exhibit sexually dimorphic tunable leucophores and iridocytes. The Journal of experimental biology, 216 (Pt 19), 3733-41 PMID: 24006348

Pagliuca, F., Millman, J., Gürtler, M., Segel, M., Van Dervort, A., Ryu, J., Peterson, Q., Greiner, D., & Melton, D. (2014). Generation of Functional Human Pancreatic β Cells In Vitro Cell, 159 (2), 428-439 DOI: 10.1016/j.cell.2014.09.040

Get Some Sleep - Your Brain Will Thank You

Sleeping may be the great American pastime. A survey from 2009 stated that over 1/3 of Americans  nap daily. Sure, 49% of Americans are professional football fans, but those games don’t occur every day, and I bet a bunch of those fans nap anytime the Jaguars are on TV.

The koala sleeps 18-22 hours a day. Their food

(eucalyptus leaves) is so difficult to digest that they

have to use a lot of their energy just to extract the

little bit of nutrition and carbohydrates from them.

This is fascinating, but I used the picture to suck you

in – they're just so darned cute!

I’ve never been much of a napper, but I live with three of them. My wife tells me that napping is just heavenly. My daughter agrees; she says sleeping late is what heaven dreams about. Unfortunately, a 2013 Gallup report found that 40% of Americans don’t get the recommended 7-9 hours of sleep each night. They only polled adults, so who knows how many kids are sleep-deprived.

We do need a considerable amount of sleep, but why? When I lose out on sleep, I find it hard to concentrate and I don’t have as much energy. I make much less sense when I’m tired, both in print and in … you know, person … like.... speaking. See this post for reasons we need to sleep.

As for kids, there are arguments now raging about how to be sure they get enough sleep. The National Institutes of Health recommends that elementary students get 10-12 hours of sleep each night. Middle school and high school students need at least 10 hr and 9-10 hr, respectively.

A movement is on to back off on the start times of middle school and high school. The American Academy of Pediatrics is recommending that high schools and middle schools start no earlier than 8:30 am. This confuses me. Won’t the kids just go to bed later? You’re not giving them more sleep, you’re just shifting their day. You want them to get more sleep? Keep handing out those worksheets in class. A different strategy might be needed, but the quest is a noble one.

It turns out that sleep isn’t just a good idea – your brain depends on it. Loads of new research is showing that brain function and even brain survival is tied to adequate sleep.

Current estimates are that only 8% of high school

students get adequate sleep on a regular basis. Does

that count the time they sleep in class? Many schools

have shifted the class day back in an effort allow them

more sleep time. I haven’t noticed a difference in

the kids at these schools.

Learning in school, or anywhere for that matter, is based on creating new neural pathways in your brain, and then reinforcing them to make them stronger. Moving new knowledge to long-term memory is based on a mechanism called long-term potentiation (LTP), where often used neural pathways begin to feedback and strengthen themselves.

The opposite is also true, in order to make the most of any new connections, you need to prune back (cause to degrade) the connections that you aren’t using. This is called long-term depression (LTD). The two mechanisms work together to help you learn, and their function is tied to adequate sleep.

Many studies have shown that sleep loss affects LTP and LTD, but a newer study indicates when it most likely to be a problem. In sleep-deprived mice, a learning session immediately followed by sleep deprivation was not as bad for long-term memory consolidation as was a learning session where the sleep deprivation was begun 1-3 hours later. Apparently, when you lose your sleep can matter more than how much sleep you miss.

So - learning is better when you have adequate sleep. But can too little sleep actually harm your brain? It turns out that yes, it can. A 2014 study from the University of Pennsylvania looked at neuron function in the locus coeruleus (LC), the part of the brain that works in alertness and problem solving.

Their experiments in a mouse model of sleep deprivation demonstrated that while a little sleep deprivation upregulated a protein (Sirt3) important for mitochondrial function, more sleep deprivation had the opposite effect. With too little sleep, the mitochondrial Sirt3 disappears and the cells can’t make ATP for energy. With no energy, they die off.

This is permanent, irreversible damage mediated by sleep deprivation. Ouch…. But wait, it gets worse. Sleep deprivation could hurt you another way. Depression is connected to sleep loss, and depression is definitely bad for your brain.

You’re looking at the hippocampus in cross section in

a regular (above) and depressed (below) person by

CT scan. The hippocampus looks like a seahorse, but

not from this angle. You can see the decrease in size

correlated with major depression.

A new study shows that depression affects the hippocampus, the part of the brain that works in long-term memory, emotional responses, and spatial organization. Connections between the different layers of the hippocampus can be lost, along with decreased communication structures on the neurons of those layers.  And this isn’t all.

Other studies indicate that patients with major depression have hippocampi that are up to 10% smaller than those in non-depressives. Loss of sleep makes you susceptible to depression or makes depression worse, and being depressed can kill your brain cells.

The above studies show that function is decreased when you don’t get enough sleep and you can do permanent damage to your brain. What if we take sleep loss to the nth degree, could it kill you? Yep.

Fatal Familial Insomnia (FFI) is a rare, genetic disease wherein individuals have a harder and harder time falling asleep. First they can’t sleep through the night and don’t enter REM sleep. Then they can only nap. At the end of the 10-18 month course of the disease, they can’t sleep at all; they enter into dementia and die.

The name of the disease is a little deceiving, it may not be the lack of sleep that kills you, although it does make life hard to endure. FFI is a prion protein disease, like Creutzfeldt–Jakob, mad cow disease, or Kuru. It’s the prion protein plaques that are the root of the problem and cause the disease. It just happens that the prion plaques from FFI first form in the parts of the brain that regulate sleep (the anterior hypothalamus and preoptic nucleus, see this post).

A great book that tells the story of prion protein

diseases, especially fatal familial insomnia is called

The Family That Couldn’t Sleep, by journalist D.T.

Max. I highly recommend it. It won’t put you to sleep.

A 2013 study showed that gene expression profiles in FFI patients are really screwed up in the thalamus and hypothalamus, including mitochondrial electron transport systems – the same type problem identified in the sleep loss and LC cell death study mentioned above.

FFI is found only in a few families, but it's devastating for them. There's no treatment, and sleeping pills seem to make it worse. It gets scarier - the disease doesn’t have to be genetic, it can spring up out of nowhere (called sporadic cases). And since it doesn’t become evident until adulthood, you could pass it on to your children before you even know you have it.

All this information makes me want to take a different attitude toward sleep. Find some time during the day to rest your eyes and make sure you get to bed at a decent time – it might just save your brain, or even your life.

Contributed by Mark E. Lasbury, MS, MSEd, PhD
As Many Exceptions As Rules

Zhang J, Zhu Y, Zhan G, Fenik P, Panossian L, Wang MM, Reid S, Lai D, Davis JG, Baur JA, & Veasey S (2014). Extended wakefulness: compromised metabolics in and degeneration of locus ceruleus neurons. The Journal of neuroscience : the official journal of the Society for Neuroscience, 34 (12), 4418-31 PMID: 24647961

Qiao, H., An, S., Ren, W., & Ma, X. (2014). Progressive alterations of hippocampal CA3-CA1 synapses in an animal model of depression Behavioural Brain Research DOI: 10.1016/j.bbr.2014.08.040

Prince TM, Wimmer M, Choi J, Havekes R, Aton S, & Abel T (2014). Sleep deprivation during a specific 3-hour time window post-training impairs hippocampal synaptic plasticity and memory. Neurobiology of learning and memory, 109, 122-30 PMID: 24380868

Tian C, Liu D, Sun QL, Chen C, Xu Y, Wang H, Xiang W, Kretzschmar HA, Li W, Chen C, Shi Q, Gao C, Zhang J, Zhang BY, Han J, & Dong XP (2013). Comparative analysis of gene expression profiles between cortex and thalamus in Chinese fatal familial insomnia patients. Molecular neurobiology, 48 (1), 36-48 PMID: 23430483