Confession of a Paris Rookie: I love métro music.

Posted on June 12, 2013 by | 9 comments

Dear Paris, 

We’ve only known each other for two weeks, and this is definitely going to sound cheesy. Here’s my confession. I am afraid I am already madly in love with you. Everything about you is perfect: the baguettes, wines, € 0.40 espresso, the countless museums and the dirty crowded métro. 

the metro

the train carrying too many people in the métro

Yes, I even love the dirty crowded métro that sometimes feels like a slaughterhouse, especially on Monday mornings. Regardless, the métro is the backbone to your existence, one part connecting to another. Occasionally, I find the true gem of the métro– the musicians. The metro musicians must audition to earn their stage. The RATP, the company that runs the métro, holds biannual auditions looking for talented musicians every year. Just today, I had the pleasure of listening to the happy and carefree accordion player when I, along with the rest of the NBB crew, nonchalantly landed on the wrong train.

jolly accordion man                                                                          (click to watch!)

So far I have seen the guitarists, violinists, an opera singer, and an accordion player, but regardless of the genre, I lose myself in the sudden rush of happiness when listening to these metro certified musicians.

In addition to the pure bliss, I quickly recall my street musicians days playing with my string quartet, thus making the experience more meaningful and emotional. One recent neuroscience study stated that there is a release of dopamine (the happy brain chemical that is also released during sex and food) in the striatum (the reward network in the brain) during the emotional experience of music (Salimpoor 2011). So this pleasure I get from music is not only attributed to the melodious tunes of the musicians but also the emotions they elicit. Additionally, the level of pleasure, measured by quantifying the dopamine release, is positively correlated to the emotional arousal (Salimpoor 2009). This may also explain why other métro travelers remain immune to this fleeting euphoria that I experience.

Then I started wondering how my musical history affected my brain. I have been playing the viola for ten years, performing at various centers, halls, weddings, parties and of course, the streets. What kind of brain changes could I have self-induced? Luckily, I was able to find a study that explored this exact question. A group of researchers in a collaborative study among McGill University, Mouse Imaging Centre, Boston College, and Harvard medical school recently published the study on how musical training shapes structural brain development of children. Because many studies have previously looked at the effect of music in the adult brain, this study distinguishes itself in not only in its exploration in the developing brain but also in relating these biological changes to behaviors (Hyde 2009).

In this study, 31 children around the age of 6 with no previous musical background participated. In the instrumental group, 15 children went through weekly half hour private keyboard lessons for 15 months, while the control group participated in a weekly general group music class in public school (Hyde 2009). To measure and assess the structural changes in the brain, the 31 children underwent an MRI scan, which is a tool that allows one to visualize the brain. There were two behavioral tests. One was a simple motor sequencing task, which is where the children press a particular number sequence that corresponds to finger 2-5. (2= index finger and 5=pinkie finger.) The second behavioral test was a melodic and rhythmic discrimination test where the children heard pairs of tunes to indicate if they were the same or different. In order to see how the instrumental training affected the children’s brain and behavior, they were tested before and after the 15 month period.

The results? Compared to the control group, the instrumental group showed bigger primary motor area, corpus callosum (the tissue that connects the left and right hemisphere of the brain), and primary auditory area. These structural differences also paralleled the behavior changes. The children in the instrumental group consistently performed better in the motor and the tune discrimination task. Basically, the children in the instrumental group demonstrated greater brain changes that greatly enhanced the way they used their fingers for motor functions and their ears to detect differences.

Although this study only looked at young children, music does not discriminate ages and benefits all! I am now starting to wonder how pervasive and practical music therapy is in the field of neuroscience…. but for now, I need some personal music therapy aka YouTubing French artists. Au revoir!

-Sehe Han the Paris rookie

References

Hyde, KL, Lerch J, Norton A, Forgeard M, Winner E, Evans AC, Schlaug, G. (2009). Musical training shapes structural brain development. The Journal of Neuroscience, 29: 3019-3025.

Salimpoor VN, Benovoy M, Larcher K, Dagher A, Zatorre RJ (2011). Anatomically distinct dopamine release during anticipation and experience of peak emotion to music. Nature neuroscience, 14: 257-262.

Salimpoor VN, Benovoy M, Longo G, Cooperstock JR, Zatorre RJ (2009). The rewarding aspects of music listening are related to degree of emotional arousal. PloS one, 4(10), e7487.

 

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Les Pâtisseries à Paris

Posted on June 12, 2013 by | 8 comments

“The treasures of France; I love Patisseries!” one of my friends of French origin exclaimed when he discovered that I had been taking full advantage of the fact that nearly every street corner of Paris is occupied by a Boulangerie, or bakery. “Window shopping” in Paris is not limited to its boutiques; in fact, what really catches my eye when walking down the street are the rows of colorful macaroons, tartes and a number of other mouth-watering pastries. However, the real reason why I’m in France is not for the pastries, although they are a delightful perk to the trip, but is to study neuroscience through Emory University. With class from 9:30am to 1:30pm, the other students on my program and I take full advantage of our hour lunch break. We have made ourselves regulars at a nearby bakery and devour their enormous baguette-sandwiches nearly every day; but perhaps even more intriguing than their sandwiches are their desserts. A friend of mine and I, each having an extremely dedicated sweet tooth, have set out to try every pastry, cookie, cake, and dessert sold by our favorite bakery. Although this may seem like a daunting task, we are now four days into our endeavor and have already sampled about a quarter of the treats offered at our bakery.

Now, being an avidly interested neuroscience student, it wouldn’t be right to discuss such amazing sensory perceptions without giving credit to the nervous system. Endocannabinoids are chemical compounds produced by the human body that act in certain areas of the brain to stimulate appetite and food intake.  Yoshida et al. (2010) studied two different groups of mice, one normal group which had the receptor for endocannabinoids, and one which had been genetically altered to lack the receptor for endocannabinoids. The lack of receptor in the second group prevents the group from being able to experience the effects of endocannabinoids. The group of researchers administered cannabinoids, synthetically made endocannabinoids, to both groups of mice and found that in those mice with endocannabinoid receptors, behavioral responses to sweet compounds increased and the response of taste receptor cells on the back of their tongues to tasting sweet compounds increased as well. In the mice without endocannabinoid receptors, no increase in behavioral or cellular activity was observed in response to cannabinoid injection. In addition, in normal mice, with endocannabinoid receptors, if the endocannabinoid receptors are blocked using a drug, the mice show a decreased response to sweet compounds. This last portion of the experiment hints to the idea that endocannabinoids may be involved in allowing the animals to perceive a sweet taste.  These findings, in general, suggest that perhaps endocannabinoids play a role in the perception and enhancement of sweet tastes. Yoshida et al.’s normal mice which were administered a cannabinoid would have really loved the desserts that I have been delving into for the past few weeks. It may be possible that as I make my way through the treats at my regular bakery, my body releases endocannabinoids, which act on certain areas of my brain that eventually communicate with my taste buds and allow me to taste the sweet, delicious desserts. Perhaps a combination of my body’s release of endocannabinoids and my love for sweets is what is propelling me so quickly through my task. At this rate I’ll be onto my next bakery in a week; watch out Paris, I’m a little girl with a huge sweet tooth.

– Ankita Gumaste

Works Cited

Yoshida R, Ohkuri T, Jyotaki M, Yasuo T, Horio N, Yasumatsu K, Sanematsu K, Shigemura N, Yamamoto T, Margolskee RF, Ninomiya Y (2010) Endocannabinoids selectively enhance sweet taste. PNAS 107:935-939.

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Fading Away…

Posted on June 12, 2013 by | 7 comments

When in Paris it is expected that you will see the Mona Lisa at the Louvre and the famous paintings and sculptures at Musée d’Orsay; but what I did not expect was to attend an exhibition full of manipulated light, motion, and optical illusions.  The Dynamo exhibition at the Grand Palais completely exceeded my expectations and quite literally messed with my perception of reality.

Location of Dynamo Exhibition

 What I would see in person did not match what my camera lens saw and often I would see images that seemed to move or change when I looked from a different angle.  One of my favorites is shown in the image below:

Optical Illusion from the Dynamo Exhibit

Unfortunately I didn’t take the best picture so it doesn’t quite work now, but at Dynamo when I stared at the center dot and rings, the outer light blue ring disappeared!  Of course my initial reaction was to jerk my head (thinking I was seeing things, or not I guess in my case) and the ring reappeared. This ended up being the intention of the piece and being the nerd that I am, I wondered how they did it. 

I did some research and found out that the phenomenon is called Troxler Fading, which is when you are fixating on a central object and the object in your peripheral vision fades away from your awareness.  Essentially your brain gets used to seeing the unvarying objects and fades them out so you can focus on the central object.  It’s similar to when you drop something in your lap, you feel it for a few seconds, and then forget it’s there until you feel it again when you move.  It is the body’s way of reducing sensitivity to constant stimuli, freeing attention to process the new things.  The diminished response to a repeated stimulus is called habituation (Lou, 1999).

One very interesting paper I found linked visual habituation (the fading) to adults with ADHD.  But first to understand the paper I had to understand how and where the Troxler Fading occurs.  Troxler Fading involves two major parts of the brain, the frontal lobe and the parietal lobe. When the parietal lobe was damaged, objects in the peripheral would fade faster than those with a functional parietal lobe.  In contrast, those with damaged frontal lobes rarely experienced any fading.  The conclusion was that the parietal lobe is necessary to maintain an image, but the frontal is important for the habituation of an object (Mennemeier et al., 1994).

Jacqueline Massa and Illyse O’Desky knew that people affected with ADHD have abnormal frontal lobe activity and wanted to see if their visual habituation was affected.  Since the damage to the frontal lobe was linked to no visual habituation, people with ADHD could have a diminished ability to fade out the unimportant things and therefore have a harder time focusing on one task.  They used several tests with Troxler fading, asking 21 adults with ADHD to indicate when the dot in their peripheral faded away.  The results of the study showed that adults with ADHD had to stare longer to get the dot to fade (habituation) than those without the disorder.  They concluded that the impaired habituation may explain why adults with ADHD have such a hard time focusing on one thing at a time; it takes longer for their brain to fade out unimportant stimuli (Massa and O’Desky, 2012).

Nerdy tangents like this are completely normal for me.  I see (or don’t see) something and have an urging desire understand it.  Most of the time I end up finding cool ways to link it to other things.  And now when I take my sister to the exhibition in July, I can explain to her how it all works, even though I’ll probably be the stimulus she fades away…

~Sarah Harrington

References:

Lou L (1999) Selective peripheral fading: evidence for inhibitory sensory effect of attention. Perception 28:519-526.

Massa J, O’Desky IH (2012) Impaired visual habituation in adults with ADHD. Journal of attention disorders 16:553-561.

Mennemeier MS, Chatterjee A, Watson RT, Wertman E, Carter LP, Heilman KM (1994) Contributions of the parietal and frontal lobes to sustained attention and habituation. Neuropsychologia 32:703-716.

 

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Baroque Music at Sainte Chapelle

Posted on June 12, 2013 by | 5 comments

 

Last week, we took a group trip to Sainte Chapelle, a Gothic church in the heart of Paris. Though many visit the church to admire the magnificent collection of 13th century stained glass and extensive collection of Christian relics, we were there to hear an authentic Baroque music concert. Much of the hour-long concert featured a trio of harpsichord, violin, and recorder, but at one point, the recorder player took a solo and switched from playing the soprano version of the instrument to the higher-pitched sopranino. After the recorder player began his solo on the stage, he proceeded to wander throughout the entire chapel—through the audience, along the walls of the chapel, and at one point even directly behind the seating area.

When I said "heart of Paris," I meant it.

As the soloist walked around far behind me, I noticed that I was able to identify where the sound was coming from even though I was facing the opposite direction. I immediately remembered a lecture from neurobiology class that covered the neural mechanisms involved in sound localization. The process depends on the fact that our brain has the ability to compare inputs from both ears. When sound emanates from a source, it usually is not exactly the same distance away from each ear, so when the sound reaches both ears, the difference is calculated and converted into an angle to the direction of the sound (Grothe, 2003). Oftentimes, the difference between arrival at each ear can be as little as 10 microseconds (that’s 1/100,000th of a second)!. This calculation of interaural time difference (ITD) occurs in the medial superior olive, a collection of cells in the brainstem.

Basis of interaural time difference

I was curious, though, if the same process was taking place during the concert. I remembered that the ITD calculations are particularly effective for low frequency sounds, certainly lower than the high-pitched sopranino recorder (Devore and Delguette, 2010). Additionally, I imagined that the tall ceiling and compartmentalized roof, typical of Gothic architecture, would create echoes that further complicate the use of ITD to localize sound. I looked into the matter, and found an article that attempted to explore how the brain’s ability to localize sound is affected by reverberation (Devore and Delguette, 2010). The researchers thought that the lateral superior olive, which uses interaural level difference (ILD) to localize sound rather than ITD, would be preferentially involved in sounds distorted by reverberation. In order to test this hypothesis, the experimenters used a technique called in-vivo electrophysiology, which places a collection of small recording electrodes into the brain and is able to isolate activity from single brain cells in awake, behaving subjects. Once the electrodes were in place, the subjects (in this case, rabbits) were exposed to a variety of auditory stimuli. The stimuli varied in direction, pitch, and reverberant nature so that the researchers could determine which pathways were in use in different situations. They found that the brain relies more heavily on ILD than ITD in reverberant situations, particularly for high-frequency pitches.

Beautiful? Yes. Reverberant? Absolutely.

While researching sound localization, I stumbled across another article that I found to be particularly interesting. I have always been amazed by conductors’ abilities to identify a single individual who misses a note in a 70-person ensemble. Researchers found that the constant exposure to wide field multi source sound environments experienced by conductors actually changes the way that conductors’ brains process the information (Münte et al., 2001). Not surprisingly, conductors outperformed both non-musical controls and pianists in accuracy of sound localization, but interestingly, recordings of brain activity during the task revealed that all groups utilized identical regions of the brain. This finding led the researchers to suggest that the intensive training and exposure that conductors receive simply trains their brain to more effectively use the sound localization pathways that we all use everyday. Take home message: the phrase “mental exercise” has a good deal of validity to it.

 – Max Farina

 

Works Cited:

Devore S, Delguette B (2010) Effects of reverberation on the directional sensitivity of auditory neurons across the tonotopic axis: influences of interaural time and level differences. Journal of Neuroscience 30: 7826-7837.

Grothe B (2003) New roles for synaptic inhibition in sound localization. Nature Reviews Neuroscience 4: 540-550.

Münte TF, Kohlmetz C, Nager W, Altenmüller E (2001) Neuroperception: Superior auditory spatial tuning in conductors. Nature 409.

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Want to Remember Paris? Take a Nap!

Posted on June 11, 2013 by | 7 comments

Since arriving in Paris I have immersed myself in a lesser-known aspect of French culture – Naps. 

While not as famous as the country’s delicious food and fine wine, the French nap, particularly when enjoyed on the banks of the Seine River or on a bus ride through Loire Valley, is a key part of the French lifestyle. In fact, napping is so important to the French that recently their minister of health, Xavier Betrand proposed that they schedule Spanish-esque siestas into the normal workday to increase napping-opportunities. He even suggested that these siestas count as paid work hours!

So, with much determination, I have subjected myself to a grueling routine of daily naps, often conveniently located at some of Paris’s most beautiful landmarks. But unfortunately this napping regime takes time, and since I’m not receiving health minister Betrand’s proposed nap-time monetary reimbursement, I needed to do some research to see if my dedication to the French culture was worth the time away from my neuroscience studies.

It turns out that napping could very well be helping my academics! There have actually been many research studies that show significant increases in ability of individuals to remember facts when they take a brief nap after learning new information. 

So what is a nap?

View of the Seine from behind Notre Dame. Location of a wonderful nap in the sun.

In order to understand the research behind nap-improved memory, it’s important first that we briefly define different sleep stages, and the different types of naps associated with each.

Non-Rapid Eye Movement Sleep (NREM): NREM sleep is comprised of 4 stages. Stage N1 is the drowsy period right at the onset of sleep. N1 is often associated with body twitches and the ability to still be somewhat aware of your surroundings. The second stage, N2, is when your muscles relax and you lose all awareness of your surroundings. This stage occupies about 40% of total sleep time. The final two stages of NREM, N3 and N4, are the deepest sleep stages and are often termed slow-wave-sleep because of their distinct shape when recorded on a electrocephologram (a machine used to measure electrical activity in the brain).

Rapid Eye Movement Sleep (REM): As the name suggest this sleep is often accompanied by rapid eye movements. Additionally, when you wake yourself up by kicking or swinging your arm it most likely occurred during REM sleep.

Long Naps: Naps that last longer than 40 minutes. Includes all stages of NREM and REM sleep. Because long naps include deep sleep phases, they are often associated with sleep inertia upon waking (the groggy-feeling where it’s difficult to get fully awake).

Short Naps: Naps between 10-40 minutes. Commonly called “power naps,” these naps normally just include stages N1 and N2, however they can include N3 if approaching 40 minutes in length. 

Ultra Short Naps: These are naps as short as 5 minutes and normally are just stage N1.

The science behind the French-nap 

Students napping on a bus ride to Loire Valley

Since sleeping between class or on a bench amongst the hubbub of tourists and street vendors doesn’t lend itself well to long naps, the majority of my sleep has been limited to 6-40 minute intervals. Interestingly, there was a study recently published in the Jounral of Sleep Research that looked at this exact length of nap and it’s effect on the ability of 18 college-age individuals to remember a list of words (Lahl et al., 2008).

The study was pretty simple, each student was given a list of thirty adjectives and told to memorize as many of them as possible. At the end of two minutes the lists were taken away and the students were broken up into 3 sleep-groups. One group was allowed to sleep for 5 minutes, another for an average of 35 minutes, and a third was not allowed to sleep at all. After 60 minutes, each student was asked to repeat the adjectives they could recall from the list. The number they remembered was recorded and averaged with the other’s in their sleep-group. This experiment was done twice more with the same students, once a week after the first test, and then again another week later. To make sure the experiment was accurate they used different word lists each time and also rotated which group slept for 6 min, 35 min, or not at all. By the end of the experiment each student had been in each sleep-group once.

The results of this experiment are great news for the French-nap! It turns out that those who took a short nap were able to remember on average 1.2 more words than those who didn’t sleep at all and students who took long naps where able to remember an average of 2.2 more words than their non-sleeping peers. While 1-2 words might not seam like a huge difference, it is considered statistically significant because of the small number of total words in each list (30 words). Also, many other sleep-memory experiments have shown similar results thus helping to confirm the data from this study (Tucker et al., 2006).

Some additional experiments have been done to show exactly how this memory-improvement occurs. When you sleep, your brain doesn’t “shut-down” like many people believe; instead parts of the brain ramp up their activity. One of these areas, the hippocampus, has been shown to be a key part of the memory-forming networks in the brain (Gorfine et al., 2007). Increasing the activity of the hippocampus during sleep is a way for our brains to rehearse the events we recently experienced, thus strengthening the connections between neurons that solidify those memories in our brain. Short bursts of sleep, such as my French-naps, are thought to specifically help in the formation of factual memories. Additional research has shown that another part of the brain, the orbitofrontalcortex, might help the hippocampus in the formation and storage of these memories (Lesburgures et al., 2011). However, this research is very recent and the connection between sleeping and its effect on the orbitofrontalcortex needs to be studied in future experiments. Until then, I’m happy to know that I now have a scientifically proven excuse to nap across Paris – I’m activating my hippocampus and helping store all of the material learned in class that day. Next stop, a nap beneath the Eiffel tower!

– Camden MacDowell

On of my many ultra short naps in the ACCENT center where we have our classes. My hippocampus is hard at work.

Works Cited

Gorfine T, Yeshurun Y, Zisapel N (2007) Nap and melatonin-induced changes in hippocampal activation and their role in verbal memory consolidation. Journal Pineal Research 43: 336-342.

Lahl O, Pietrowsky P, Wispel C, Willigens B (2008) An ultra short episode of sleep is sufficient to promote declarative memory performance. Journal of Sleep Research 17: 3-10.

Lesburgures E, Alaux-Cantin O, Bontempi B, Gobbo A, Hambucken A, Trifilieff P (2011) Early tagging of cortical networks is required for the formation of enduring associative memory. Science 331, 924-928.

Tucker M., Chaklader A, Fishbein W, Hirota Y, Lau H, Warnseley E (2006) A daytime nap containing solely non-REM sleep enhances declarative but not procedural memory. Neurobiology of Learning and Memory 86: 241-247

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Music at Notre Dame

Posted on June 11, 2013 by | 7 comments

Before coming to Paris, there was one trip I knew I absolutely wanted to make: a visit Notre Dame. I spent the previous spring semester reading a few pages every night of Victor Hugo’s unabridged Hunchback of Notre Dame, and I was hooked. Of course the hunchbacked madly-in-love Quasimodo didn’t exist, nor did the dashing dusky beauty Esmeralda or the creepily obsessive Frollo, but still the book stirred a deep interest in visiting the ancient cathedral. I yearned to visit the chiseled stone, to see the spires where Quasimodo was fabled to have climbed, to roam the streets that Esmeralda looked down upon from her cage in the towers. Notre Dame had a fairy tale appeal, except unlike in fantasies, this one is real, and it was waiting for me.
Unfortunately the church wasn’t on our list of scheduled sites, so I just had to go visit it on my own. After class one day, a few friends and I took the metro over to bask in the ambience of Notre Dame. It’s in the heart of Paris, situated on a small island called Île de la Cité, or ‘Island of the City,’ surrounded by the river Seine. A screenshot of Google Maps below will help draw the picture (‘A’ is Notre Dame):
Crossing the river, my jaw dropped as my eyes flew up—I could finally see the renowned towers with my very own eyes!

The building was enormous, and of course stunning. Above and around the ornate doors were statues representing biblical images in breathtaking detail.

The line to enter was extremely long, and we had plans later that evening, so we decided to take a stroll around the church instead. Just as we turned the corner, we saw a young man walk up the sidewalk with a giant instrument case. He sat on a folding stool and pulled out stringed instrument resembling a cross between a lyre and a guitar. What happened next blew me away: he began plucking his instrument, and melodious music filled with the regality and crispness of the Renaissance period flooded the street.

Hopefully the link below works…it may take a second to load.

Click here to watch him perform!

I felt a wave of relief pass over me, like nothing in this world could deter my peace at that moment. All of my worries and problems seemed to melt away in the little time I stood there, listening to him play music from the past. Overhead loomed the elegant spires of Notre Dame, and the combination of church and music was unreal. I couldn’t leave without giving him some change, knowing all too well that the amount I spared can never match the amount of joy he gave.

Researching our body’s response to music, I realized why I felt so much happiness just standing there listening to the musician. A study by Salimpoor et al. focused on dopamine, a chemical sent between nerve cells in the brain that is involved with experiencing pleasure (2011). Previous research has shown that dopamine is released in a region of the brain called the mesolimbic system, which is involved in motivation and feelings of reward (Schott et al., 2008). Humans gain pleasure not only from eating food and social interaction, things necessary for survival of prehistoric mankind, but also from “abstract stimuli, such as music and art” (Salimpoor et al., 2011).
This study tried to determine the role of dopamine released during “moments of extreme pleasure,” in this case listening to music. The downside is that pleasure is hard to quantify. To overcome this issue, the researchers looked at the bodily changes accompanying pleasurable sensations, like the “chills” that people feel when listening to certain types of music. The good kind of course, not the creepy kind. To get these chills, participants in the experiment listened to music that they liked. Chills can elicit changes in heart rate, breathing rate, and body temperature. By studying these changes, researchers can thus use an objective phenomenon (chills) to describe a subjective experience (pleasure). Lastly, to record dopamine release, the researchers used positron emission tomography (PET) scans, a lab technique that basically images the brain using radiographic tracers.
Enough of the background stuff, let’s get into the real experiment. Participants either listened to neutral music, or music they liked. They also gave subjective responses to their chills, like the number of times they occurred and how intense they felt.  Compared to those that listened to neutral music, the participants that listened to music they liked felt more pleasure, and thus had more chills. The chills were also shown by bodily changes, including an increase in heart rate and breathing rate and a drop in body temperature. The PET scans depict an increase in the amount of dopamine sent between cells in the mesolimbic system. Thus, Salimpoor’s research concludes that dopamine release is associated with the pleasurable sensation of listening to music, which causes a feeling of pleasure and chills.
Now I see why I felt those chills when I stood there at Notre Dame that day. The music caused a release of dopamine in my brain, giving me the sensation of pleasure so that I could enjoy the experience for as long as I was there. The chills are just the byproduct of that pleasure, so that I realize just how much I like the music. Hopefully I can go visit Notre Dame again one day. If I do, I hope that the musician is there again—I’m ready for some more dopamine release with the sound of his out-of-this-world music!
-Mayur Patel

References
Salimpoor V, Benovoy M, Larcher K, Dagher A, Zatorre R (2011) Anatomically distinct dopamine release during anticipation and experience of peak emotion to music. Nature Neuroscience 14: 257-262
Schott B, Minuzzi L, Krebs R, Elmenhorst D, Lang M, Winz O, Seidenbecher C, Coenen H, Heinze H, Zilles K, Duzel E, Bauer A (2008) Mesolimbic Functional Magnetic Resonance Imaging Activations during Reward Anticipation Correlate with Reward-Related Ventral Striatal Dopamine Release. The Journal of Neuroscience 28: 14211-14319

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Château de Villandry and Lemon Balm

Posted on June 11, 2013 by | 7 comments

This past Saturday, we took a three-hour bus ride from Paris to the Loire Valley to visit two famous chateaus:  the Château de Villandry and the Château de Chenonceau.  Château de Villandry especially caught my attention because despite its rather plain exterior compared to other chateaus. It has one of the most beautifully designed gardens.  Château de Villandry have a long history since the 14th century, but most recently, Joachim Carvallo, a Spanish doctor and researcher, bought the property in 1906. As we stood on the upper levels of the chateau, I was amazed by the geometric designs of the decorative gardens that represented tender, passionate, fickle, and tragic love.  Carvallo renovated the château and designed medicinal gardens to further his research.  In addition to the medicinal herb garden, there are also flower gardens, vegetable gardens, and waters gardens, which are representative of renaissance style chateaus.

Chateau de Villandry

Decorative gardens in Chateau de Villandry

The medicinal herb garden is farther away from the main building because it was built in the 1970s by Carvallo’s grandson according to his original design.  The garden contains various different types of herbs, roots, and leaves that have therapeutic properties.  As I was meandering through the garden slowly, a slight scent of minty lemon caught my attention.  The scent originated from a little bush with green leaves that resembled the shape of mint leaves.  A little web browsing showed that the plant is called lemon balm, or Melissa officinalis.  Lemon balm is usually used to make herbal tea, which I don’t particularly like.  However, since Carvallo chose to have lemon balm planted in his herb garden, I am curious to find out the beneficial effects of this nice smelling plant.

Lemon balm has various therapeutic properties ranging from lowering anxiety to treating Alzheimer’s disease (Maguire et al.).  Lemon balm has such a wide variety of therapeutic uses because of its effects in many neurotransmitters that are important for neuron communication in the body.  Neurotransmitters are molecules secreted by one neuron to another for signaling purposes; most of them can be divided into two categories.  One group of neurotransmitters will increase the activity and electrical firing of the recipient neuron.  The other group of neurotransmitters will decrease the activity and electrical firing in the neuron receiving the molecules.

Lemon Balm (By quinn.anya)

Among many studies investigating possible usages of lemon balm for treating different diseases, a study on lemon balm extract’s ability to induce neurogenesis in dentate gyrus of hippocampus, an area of the brain that is responsible for forming new memories, seems particularly promising for treating many memory related diseases such as Alzheimer’s (Yoo et al., 2011).  Neurogenesis in the dentate gyrus focuses on the formation of granule cells, a cell type that is thought to be responsible for spatial memories (Colicos and Dash, 1996).  The process of neurogenesis starts with the proliferation of granule cell progenitors in the subgranular zone, which then migrate to the granule cell layer where the new granule neuronal cells are made (Yoo et al., 2011).

To see if lemon balm actually promotes neurogenesis, Yoo et al. set up three groups of mice.  The first group was fed with 50mg/kg lemon balm extract, the second group received a higher dose of 200mg/kg, and the last group is a control group in which the mice were fed with distilled water (Yoo et al., 2011).  All three groups were fed once a day for 21 days.  To track the effect of lemon balm on neurogenesis in the dentate gyrus, we have to monitor several proteins that are produced as by-products of neurogenesis.  Ki-67 is a protein that will be present in the cellular nucleus during cell proliferation.  DCX, another protein, is expressed in immature neurons, which is indicative of new neuron formation.  To see if these proteins are made in the dentate gyrus, antibodies that will attach themselves specifically to these two proteins were used.  To quantify how many antibodies are attached to these two proteins, a stain was performed on sections of the dentate gyrus after the antibodies were administered (Yoo et al., 2011).

The results of this study is astonishing in which there is a 7-fold increase in the level of Ki-67 in the mice group that received 200mg/kg lemon balm compared to the control group that received water.  Similarly, there is also significant increase in the level of neurons expressing DCX in the dentate gyrus for the two experimental groups that received lemon balm extract (Yoo et al., 2011).  The combined increases in expression of these two proteins indicate that neurogenesis of granule cells are increased due to the intake of lemon balm extract by the mice.

Although there are still many differences between mice and human, I think it wouldn’t hurt to drink some lemon balm tea once in a while.  If granule cell neurogenesis can be induced by lemon balm extract as suggested by the mouse model, drinking some lemon balm tea might actually improve my spatial memory and help me navigate through the complex RER and metro system in Paris! 

-Eric Yao

 

References:

Colicos MA, Dash PK (1996) Apoptotic morphology of dentate gyrus granule cells following experimental cortical impact injury in rats: possible role in spatial memory deficits. Brain Research 739:120-131.

Maguire MA, Dvorkin L, Whelan J Boston Healing Landscape Project – Melissa Officinalis. In. Boston University School of Medicine.

Yoo DY, Choi JH, Kim W, Yoo KY, Lee CH, Yoon YS, Won MH, Hwang IK (2011) Effects of Melissa officinalis L. (lemon balm) extract on neurogenesis associated with serum corticosterone and GABA in the mouse dentate gyrus. Neurochemical research 36:250-257.

 

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Posted in Neuroscience

Monet and Memory

Posted on June 11, 2013 by | 11 comments

Claude Monet's "The Rue of Montorgueil in Paris. Celebration of June 30, 1878"

If you quickly glance at Claude Monet’s “The Rue Montorgueil in Paris. Celebration of June 30, 1878” as you visit the Musée d’Orsay, you can instantly recognize individual objects in this scene depicting a french celebration with crowds of people walking in the street. Look closer. The blocks of color on the flags are so blurred you may have trouble distinguishing one flag from the next. The crowds of people in the street are almost inseparable into individual persons. The typical Parisian gates on the bottom of the windows are nothing but dark blotches. Still, you can recognize these objects and people for what they are, even in a painting you have probably never seen before.

Musée d'Orsay in Paris, France

This ability has to do with a kind of memory your brain uses to identify something that you see, and it is called “object-recognition” memory (ORM) (Winters et al., 2008). Generally, the hippocampus is a brain part known to be very important in this kind of memory (Winters et al., 2008). This structure mainly houses declarative memories, such as the abilities to remember the name of the dessert that you picked up at a boulangerie or to tell taxi drivers the address you’re staying at while in Paris (Winters et al., 2008). Despite the importance of the hippocampus, it is not the only structure in the brain that houses memory. Brain structures like the orbitofrontal cortex, amygdala, and cerebellum also house components of memory. Even recently, parts of the cortex that decode visual information have been found to be important in certain types of memory, like ORM (Winters et al., 2008).

The brain processes visual information in a hierarchical manner. The photoreceptors in the eye sense spots of light and send signals to other neurons in the brain that activate to increasingly specific images. An important part of this system is the area known as V2, which splits into two parts. The lower area, known as the ventral part, allows for the abilities to tell the shape of a baguette, the size of the Eiffel Tower, and the color of the bright red strawberries in the markets (López-Aranda et al., 2009). In an attempt to try to decode this part of the brain, researchers have been looking at this part of the cortex to determine which neurons do what. Certain neurons in layers of this cortex have been tested, such as the layer 3 neurons playing a part in visual processing; however, the function of layer 6 neurons in this area remained a mystery (López-Aranda et al., 2009). In a recent study, López-Aranda and associates took on the challenge of determining the function of these neurons in the 6th layer of this part of the visual cortex (López-Aranda et al., 2009). The researchers hypothesized that these neurons play a role in ORM (López-Aranda et al., 2009).

To determine the function of neurons in layer 6, López-Aranda and associates set up an experiment where rats would have the opportunity to recognize objects they had seen before (López-Aranda et al., 2009). The experimenters placed two identical objects with the rats for three minutes, then they removed the items (López-Aranda et al., 2009). Later, during testing sessions at different timepoints, the rats had the opportunity to explore one of the old items and a new item that they had never seen (López-Aranda et al., 2009). The amount of time that the rats spent around each of the objects, old and new, was measured (López-Aranda et al., 2009). If the rats spent a great deal of time around the new item and ignored the old item, the researchers concluded that the rats remembered the old item using ORM, and they would rather use their time to explore the novel item (López-Aranda et al., 2009). If the rats spent an equal amount of time around the old and the new item, then the rats did not remember the old item and spent time examining both the new and the old items (López-Aranda et al., 2009).

The normal rats were able to remember the old object for 45 minutes, but not for 60 minutes (López-Aranda et al., 2009). When the researchers inserted more RGS-14 genes, which produces a regulator of G-protein signaling protein, into layer 6 neurons of the V2 cortex three weeks before the ORM testing, the rats remembered the object for at least 24 weeks (López-Aranda et al., 2009). With more of the RGS-14 protein in these neurons, the rat’s had longer ORM (López-Aranda et al., 2009). To make sure that this ORM enhancement was unique to this combination of RGS-14 protein in the layer 6 V2 neurons, this protein was overexpressed in three other brain locations and there was no significant ORM increase (López-Aranda et al., 2009).

Further proving their point, López-Aranda and associates killed off the neurons in layer 6 of V2 with the hypothesis that this would hinder ORM (López-Aranda et al., 2009). At 45 minutes, the rats with the missing neurons did not spend more time around the new object; they couldn’t remember that they had seen the old one before (López-Aranda et al., 2009). Just to make sure that the ORM ability was unique to V2 layer 6 neurons, neurons in other structures were eliminated (López-Aranda et al., 2009). These eliminations did not change the rats’ ORM ability to remember the old object (López-Aranda et al., 2009). Based on these data showing that increased RGS-14 protein expression in layer 6 neurons of V2 increases ORM memory, and elimination of the layer 6 V2 neurons decreases ORM memory, the experimenters wondered if these neurons were important for ORM memory formation or if they were the sites where the ORM memories were stored (López-Aranda et al., 2009).

In one more experiment, rats that had increased RGS-14 protein in the layer 6 neurons of V2 were exposed to new objects (López-Aranda et al., 2009). After that, the neurons in this layer were destroyed (López-Aranda et al., 2009). The rats had some ability to recall the objects that they had previously seen, but if they were exposed to objects after the neurons were destroyed, they could not remember them at all (López-Aranda et al., 2009). This experiment shows the importance of V2 layer 6 neurons in acquiring the memory, but because the rats remembered the old objects they had seen before the neurons were destroyed, this memory could not have been stored in the V2 layer 6 neurons (López-Aranda et al., 2009). While the V2 layer 6 neurons may not house the memories that allow you to recognize objects, they are important in being able to form the memories so you can recognize the French flags and the people in Monet’s painting (López-Aranda et al., 2009).

To wrap up this post, your visual system is even more amazing than just being able to sense the brushstrokes and colors when you look at the impressionist paintings in the Musée d’Orsay. Parts of it have to do with making memories of what you have seen, so that you can apply them to your future experiences. The brain is just like the deep ocean or distant space; we are figuring it out, but so much remains unknown. This study shows that the visual system is involved with more than just processing visual information. Just like in Monet’s painting where the lines that define the objects are blurred, the functions of the visual cortex seem to be unclear as it is is implicated for other things besides vision, like ORM.

Works Cited

López-Aranda, M. F., López-Téllez, J. F., Navarro-Lobato, I., Masmudi-Martín, M., Gutiérrez, A., Khan, Z. U. (2009). Role of layer 6 of V2 visual cortex in object recognition memory. Science 325:87-89.

Winters, B. D., Saksida, L. M., Bussey, T. J. (2008). Object recognition memory: neurobiological mechanisms of encoding, consolidation, and retrieval. Neuroscience and Biobehavioral Reviews 32:1055-1070.

Picture Citations

https://commons.wikimedia.org/wiki/File:Monet-montorgueil.JPG

http://commons.wikimedia.org/wiki/File:Musée_d’Orsay.jpg

http://commons.wikimedia.org/wiki/File:7e_arrondissement_paris.JPG

The Musée d'Orsay is located in the top right hand corner of this map of the 7th arrondissement in Paris

 ~ by Emily Aidan Berthiaume

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Musée du Louvre

Posted on June 11, 2013 by | 14 comments

The overwhelming feeling landing in Paris just a few short weeks ago can only be described as a combined wave of nervousness, anxiety and excitement.  I didn’t expect to feel that sensation again so soon, but walking into the Louvre brought the same, overwhelming rush. I was amazed by the architecture of the building and its’ perimeter and tried not to look like a typical tourist stopping to take pictures along every step of the way. After attempting to blend in with the crowd by buying some “French” coffee, we grabbed a map of the museum and (blindly) picked a starting point.

Musée du Louvre

We started with the Ancient Egyptian exhibit, which was confusing given the French descriptions mounted by all of the pieces. The intricacies of the hieroglyphics, artwork and tools, however, transcended the language barrier. After walking through, we were tired (we had climbed the Eiffel Tower earlier that day) and decided to head to one more piece before completing our day—the famous Mona Lisa.

Ancient Egyptian Art

Following the crowd, we made our way to the other side of the museum and quickly saw the international amalgamation surrounding this infamous painting. How is it that this one painting can draw so much attention from so many different people? Part of the interest in this picture lies in the mystery behind its creation—why did Leonardo da Vinci paint this picture? Who is the woman depicted here? Is she real? These questions are unanswered and add to the mystery associated with this artwork. One of the elements of this painting that interests people from across disciplines and countries is the ambiguity in Mona Lisa’s smile.  When we look at this infamous smile in the context of neuroscience, we should consider the role of visual perception. Visual perception in itself is a bridge between art and science, as this is the type of information processing that takes different visual stimuli from our environment and processes them into a “single”, interpretable unit. Visual perception is broken down into different elements such as visual closure, memory, form constancy, spatial skills and more (Chakravarty 2011). All of these factors contribute to how we perceive the outside world via our vision.

Scientists have taken this described cognitive approach to vision and have applied it to different areas of the brain. They have found that vision and interpretation of what we see relies on multiple brain areas. The primary visual area is referred to as V1, and next to this area are different, specialized regions such as V3 (recognizes the shape and size of an object), V4 (color perception) and V5 (essential in identifying object motion) (Chakravarty 2011).

The Mona Lisa

Taking a step back, it is clear that there are multiple parts of the brain with their own specific, intricate mechanisms that can affect the way faces and objects, for example the Mona Lisa, can be perceived and processed across any given population. The human visual system has allowed us to, over time, develop specific visual skills that correspond to face perception (Haxby et al., 2000). For example, individuals with brain damage in the ventral occipitotemporal cortex (an area in the brain associated with visual perception) have difficulty in recognizing faces—but can recognize objects with ease (Haxby et al., 2000). This condition, prosopagnosia, is one that supports the claim that there are very specific areas in the brain associated with face perception—perhaps providing a neurological reasoning behind the fascination with the Mona Lisa. The fact that this is a portrait of a mysterious face might be driving the worldwide fascination.

When actually getting a better look at the Mona Lisa after pushing through the crowds of people, the neuroscience student in me couldn’t help but wonder how many different neurobiological systems were working in order for me to appreciate this piece of art. I had to focus on the picture, discern the face from the background, take in account of the colors, recognize that this was a portrait, and attempt to make associations and recall what I had learned about this piece in my high school art class. Aesthetic preference is yet another factor that has significant neurological underpinnings. Cela-Conde (2011) found, through various neuroimaging studies, that certain areas in the brain (the hippocampus, parahippocampal gyrus and the amygdala) are all actively engaged when individuals are aesthetically pleased with a piece of artwork. When patients with neurological conditions (in which these areas degenerate) are presented with previously “pleasing” pieces of artwork, the patients show a completely altered taste and preference. This supports that these areas of the brain have some influence over the cognitive perception and appreciation of artwork. Similarly, studies have reported that damaging the amygdala (an area of the brain primarily associated with emotion) can alter artistic, visual preference. Individuals with amygdala damage generally expressed a liking for “…geometrical shapes, landscapes and color arrangements” when compared to the healthy, control groups (Cela-Conde et al., 2011).

Mona Lisa Selfies...

Perhaps the fascination with the Mona Lisa is brought about by the evolutionarily driven sensitivity to faces. Or, maybe there is a genetic predisposition in some of our brain’s visual areas to appreciate certain types of artwork. Some scientists even suggest that the ambiguity in her smile activates area V5, an area of the brain involved in perceiving movement, which enhances aesthetic appeal (Chakravarty 2010). Regardless of the reasoning, there are complex neurological mechanisms by which we process not only the Mona Lisa, but also every other sculpture, painting or realistically anything in our visual field. Visual perception in itself relies on cognitive theories and activation of various brain areas to yield some form of appreciation of art—now try not to think about that next time you go to a museum.

Written by: Noareen Ahmed

References:

Cela-Conde C, Agnati L, Huston J, Mora F, Nadal M (2011) The neural foundations of aesthetic appreciation. Progress in Neurobiology 94: 39-48.

Chakravarty A (2010) Mona Lisa’s smile: A hypothesis based on a new principle of art neuroscience. Medical Hypotheses 75: 69-72.

Haxby J, Hoffman E, Gobinni M (2000) The distributed human neural system for face perception. Trends in Cognitive Sciences 4: 223-233.

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NBB in Paris!

Posted on May 20, 2013 by | 2 comments

Welcome to NBB in Paris! The course uses the format of an open-access blog to help the students develop their communication skills via feedback from peers and the public audience. Each student will connect their experiences in Paris with a current neuroscience research finding and convey that information here, as interestingly and as accurately as possible. This is not an easy task but one that I believe is becoming increasingly important in our world of  instantaneous information. In my opinion, the future scientists, health professionals, engineers, or mathematicians have an obligation to be the translators of complex technical information to the non-expert public. Without these communicators, the task of being informed citizens, able to make hard decisions about personal health or public policy, becomes much more difficult.

Be sure to check back to see the latest posts…and comment freely!

Kristen Frenzel, Ph.D.

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