Monthly Archives: June 2015

Less Work, More Play!

Posted on June 22, 2015 by Danielle Toni-Ann McFarlane | 2 comments

Having lived my entire life in the USA, a country that takes pride in their ideology of the “American dream” (which, if we’re being honest, is working AT LEAST a 40 hour work week in hopes of becoming powerful and wealthy…). And furthermore, being born and raised in the big N-Y-C, I’m used to things i.e. restaurants, shopping malls, supermarkets etc. virtually being open 24/7. So, it was a major culture shock to me when I tried to go to a boulangerie one Sunday afternoon to satiate my hunger and to much dismay, found out that it was not open after I walked all the way there. As I enter my 5^th week studying abroad in Paris, this French-styled siesta continues to be a difficult concept for me to wrap my head around.

The French love their time off! Most French people work a 35-hour work week with 5-weeks paid vacation time that is not including their time off for holidays. I’ve noticed many restaurants only open for brunch and again for dinner, and most remain closed on Sundays. Major shopping malls like Galeries Lafayette, BHV, and Printemps aren’t open on Sundays as well. This is so bizarre to me; Sunday, a day where major American cities would grapple at the opportunity to capitalize off of their tourists, is the day the French chose to rest. They seem to not care so much about such trivial things like making a profit. Why? Doesn’t everyone love money? The French would rather their long lunches at the nearest café and their Sundays off to spend time with their families or significant other. After doing some research, I propose that the French place a higher value on social interaction and leisure. Some may call the French lazy, but I say no: the French are simply in love with oxytocin (granted the immense amount of Parisian PDA I’ve witnessed). Oxytocin is a hormone that acts like a neurotransmitter in the brain and is released by the hypothalamus. In humans, oxytocin is thought to be released during hugging, touching, and orgasm in both sexes, it induces a general sense of well-being including calm, improved social interactions, increased trust, and reduced fear (Ishak et al., 2011).

Typical Parisian Cafe, near ACCENT (where I take classes).

A recent study looked at the social buffering hypothesis and the governing effects of oxytocin (Smith and Wang, 2014). The social buffering hypothesis states that social animals are better able to recover from stressful experiences (i.e. the work-place) through positive social interaction (Kikusui et al., 2006). The researchers hypothesized that oxytocin plays a role in the stress response in rodent models. To test this hypothesis, female prairie voles were exposed to 1-hour immobilization stress and then recovered alone or with their male partner to mimic the effect of social contact. They then treated immobilized female voles recovering alone with oxytocin or vehicle and female voles recovering with their male partner with a selective oxytocin receptor antagonist or vehicle. If the researchers did not use the appropriate controls, we would not be able to determine the mediating effects of oxytocin on the stress response. The researchers found that 1 hour immobilization decreased the amount of time female voles recovering alone explored the open arms in an elevated plus maze and increased corticosterone levels in comparison to female voles recovering with their partners and the controls (Figure 1). Intra-paraventricular nucleus oxytocin injections reduced behavioral and corticosterone responses to immobilization, whereas injections of an oxytocin receptor antagonist blocked the effects of the social buffering. The male partner acted as a social buffer which increased oxytocin release in the paraventricular nucleus (PVN) of the hypothalamus in the female. Using an enzyme-linked immunosorbent assay, the researchers found that immobilized female prairie voles that recovered with a male partner had a significantly lower level of oxytocin in the PVN compared with other groups (Figure 3C). By use of microdialysis, the researchers identified increased levels of extracellular oxytocin concentrations (Figure 4B). These data demonstrate that PVN oxytocin release is increased with social interaction.

I chose this paper to propose a reason for the short work weeks many Parisians possess. The French seem to understand the necessity of healthy human interaction when it comes to the everyday stresses of life. Money can make someone happy only for so long, but in the end, it’s the meaningful connections with others that are maintained over these lunch breaks and restful weekends that can aid in lowering stress levels and increasing happiness. Both factors makes for a healthier individual. Hmm, maybe NYC should shut down on Sundays… Ha! Now that’s never going to happen. Just the thought of Times Square without people seems rather ridiculous, better yet scary O_O!

Until next time! Au revoir!

-Danielle

References

Ishak W, Kahloon M, and Fakhry H. (2011) Oxytocin Role in Enhancing Well-being: A Literature Review. Journal of Affective Disorders 130(1-2): 1-9.

Kikusui T., Winslow J. T. , and Mori Y (2006) Social Buffering: Relief from Stress and Anxiety. Philosophical Transactions of the Royal Society Biological Sciences 361(1476): 2215-2228.

Smith A., and Wang Z. (2014) Hypothalamic Oxytocin Mediates Social Buffering of the Stress Response. Biological Psychiatry 76(4): 281-288.

2 Comments

Posted in Neuroscience

A Creature of “Habit”

Posted on June 22, 2015 by Morgan Leigh McNair | 2 comments

Nearly every morning for the past four weeks, I go to Le Pain Quotidien on Rue de Charonne at 9:05, sit at the long wooden table, order “deux oeufs BIO à la coque et un café crème avec lait de soja” (two organic soft-boiled eggs and a soy latte), and enjoy a nice breakfast before my first class begins at 10. After Dr. Shreckengost’s morning class, I take a leisurely walk from the Accent Center to Le Bar à Soupes, also on Rue de Charonne, wait outside the restaurant until the owner opens the door at 12:00pm, and order one of the six soups of the day “à emporter” (take away).

Le Pain Quotidien and La Bar à Soupes in relation to the Accent Center

Both the waitress at the Le Pain Quotidien and the owner of Le Bar à Soupes identify me as a regular customer. I no longer need to order when I go to breakfast because the waitress knows I order the same thing every morning. The soup bar owner even gave me a Soup Stamp Card to fill up and receive a free soup after 10 purchases! Many friends on my study abroad trip have quickly surmised from my daily routines that I am a “creature of habit,” so I began to wonder how we form habits.

My filled-out Soup Card!

Do I keep going back because of the comforting food and friendly faces or is there another underlying, physiological reason? What differentiates a habit from a choice?

First, let’s start with the definition of habit. From a scientific perspective, habits are “a form of goal-directed [automatic] behavior” (Aarts and Dijksterhuis, 2000). Goals can activate habitual actions. Take an example of biking to school every day: once someone develops this habit, the activation of the goal, going to class, may automatically elicit a habitual response, biking.

Now that we understand what habits are, let’s examine how habits may actually form in our brains!

In a study conducted by Wang et al. (2011), researchers investigated the mechanisms underlying learning and forming habits. Prior research revealed the importance of the neurotransmitter known as dopamine (DA) in habit learning. In both human and rodent models, an impaired ability to form habits correlated to degeneration of dopaminergic neurons. Wang et al. (2011) examined the importance of DA even further by looking at the impact of specific receptors on DA neurons. The researchers bred mice that lacked N-methyl-D-aspartate receptors (NMDARs) on their DA neurons (NR1 mice). NMDARs are glutamate (a type of neurotransmitter) receptors found in nerve cells that play a crucial role in synaptic plasticity—the ability of neuronal synapses to change shape or function in response to activity – and memory function. Wang et al. then hypothesized that the NR1 mice, lacking NMDARs on their DA neurons, will have impaired habit learning as compared to normal, wild type (WT), control mice.

First, researchers tested if WT mice differed from NR1 mice in various abilities other than habit learning, such as fine motor movements, balance, general endurance, anxiety levels, and object recognition. The WT and NR1 mice did not differ in their abilities, proving NR1 mice to be suitable models for testing differences in habit learning. To test the impact of the NMDAR deletion on DA neurons cellular processes, the researchers recorded both WT and NR1 mice DA neuron activity in response to the dopamine receptor agonist apomorphine through electrodes inserted into the ventral tegmental area, an area of the brain that serves as the origin of dopaminergic cell bodies. The researchers discovered reduced activity in the NR1 mice, indicating the NR1 mice DA neurons did not exhibit as much activity in the presence of dopamine or dopamine agonists as compared to WT controls. Additionally, the NR1, as compared to WT, DA neurons showed decreased responses during paradigms testing reward-predicting cues over three days, showing that the NR1 mice exhibited greatly lowered bursting responses, known as DA neuron blunting, and that NMDARs play a crucial role in dopaminergic cell activation.

Figure 8 – Wang et al.
The researchers designed these Water-Filled Zigzag Maze-Based Habit Tasks to more obtain more direct measurements of habit learning by eliminating the competition factor between “spatial” and “habit” memory systems the NR1 deletion may have skewed. You can see a significant difference habitual learning ability between NR1 mice (blue) and WT mice (green).

To investigate habit learning deficits in NR1 mice, the researchers tested both NR1 and WT mice in a lever-pressing operant-conditioning task. This task, pressing a lever to obtain food, can transform goal directed responses into habitual responses through extensive training. Over time, mice typically become desensitized to outcome devaluation, the decrease in reward value. Wang et al. (2011) discovered that the NR1 mice showed a significant difference in lever presses from Non-Devalued to Devalued outcomes, suggesting that the NR1 mice failed to develop the lever pressing habit, and their actions remained goal directed. The researchers continued to test habit learning through various maze-like paradigms and discovered that the NR1 mice showed habitual learning, but not spatial memory, impairments as compared to WT controls.

Wang et al. (2011) studied the importance of DA neuron NMDARs in habit learning and formation both on a behavioral and a cellular level, providing various methodological analyses for their findings. Their control experiments testing the differences in behavior for NR1 and WT mice provided clear evidence that the researchers could use the NR1 mice to only test behavioral differences in habit learning. Additionally, the researchers discovered an interesting phenomenon exhibited in some DA neurons – decreased and then rapidly increased responses to negative experiences – suggesting the importance of NMDARs extend beyond habit formation of reward stimuli and may apply to habitual learning through the reward of escaping negative stimuli (Wang et al., 2011).

The findings of this study not only provide the scientific community with better understanding of the crucial role NMDARs play in habit formation but also lay the groundwork for future researchers to better understand the underlying mechanisms of habit disorders, such as Obsessive-Compulsive Spectrum Disorders. Who knows, maybe even executives at Starbucks rely, in part, on the science behind how and why people form habits to boost their sales and marketing efforts.

Getting lunch at Le Bar à Soupes – yum!!!

For me, my taste buds thanks my DA neurons NMDARs for their role in my behavior to seek yummy foods at the same places every day. Based on the information in Wang et al.’s study and the Aarts and Dijksterhuis (2000) definition, I am not sure if my daily trips to Le Pain Quotidien and Le Bar à Soupes have fully transitioned to a “habit” as, without the delicious food and friendly faces, I would likely seek other rewards. While habits are the result of reflexive and automatic behavior (Dolan and Dayan, 2013), I still make the reflective decision to seek the reward my reliable breakfasts and lunches provide me. I find comfort in routine, especially amid a busy schedule in an unfamiliar country. While many people use the colloquial phrase “creature of habit,” I think of myself as more of a creature of conscious goal-directed behavior… who likes consistency in my rewards 🙂

References:

Aarts H, Dijksterhuis A (2000) Habits as knowledge structures: automaticity in goal-directed behavior. Journal of Personality and Social Psychology 78(1): 53-63

Wang LP, Li F, Wang D, Xie K, Wang D, Shen X, Tsien JZ (2011) NMDA Receptors in Dopaminergic Neurons Are Crucial for Habit Learning. Neuron 72(6): 1055-1066.

Dolan RJ and Dayan P (2013) Goals and Habits in the Brain. Neuron 80(2): 312-25.

2 Comments

Posted in Uncategorized

Twenty-one and trying to keep it sober

Posted on June 22, 2015 by Nicole Asante | 5 comments

To an American, turning twenty-one means more than adding a hyphen to your age. On June 8^th, I got a call from my parents back in Rhode Island not only to wish me a happy birthday but also to pass along several warnings about what everyone associates with a twenty-first birthday: alcohol. “We trust you,” they said, “but make good decisions!”

My birthday week, however, played out nothing like my parent’s expected. I received three fantastic birthday cakes and dozens of birthday wishes, visited the beautiful town of Blois, France and the Versailles castle, and witnessed an unbelievable circus performance at Le Folies Bergere. Alcohol didn’t interest me, and for a moment I thought my parent’s advice about alcohol didn’t apply to me this trip. After our group took an excursion to Le Musee Gourmand du Chocolat, a chocolate museum complete with a chocolate workshop and demonstration, I realized that I should have applied my parent’s advice applied to my chocolate eating habits, not my first glass of wine. If I eat more than a few Hershey’s Kisses worth of chocolate I experience symptoms like coughing, temporary tightening of the throat, migraines, dizziness, and light-headedness. Over the years, I learned to live with this food sensitivity, and yet, finding myself surrounded by chocolate during the excursion did nothing to curb my cravings. As I usually do when offered chocolate, I ate far over my limit and dealt with my pounding head at the end of the visit.

I may have a chocolate problem–I might go as far as calling myself a chocoholic–but I’m not alone. Chocolate is one of the most craved foods in the United States (Heatherington and Macdiarmid, 1993). Although studies with dark chocolate suggests it can lower blood pressure (Ried et al., 2010), over-consumption of it can lead to health deficits like weight gain, or in my case, headaches and sore throats.

A: Blois, France B: Versailles, France C/D: The Chocolate Museum and circus within Paris

A: Blois, France
B: Versailles, France
C/D: The Chocolate Museum and the Kermezzoo circus within Paris

A study by Kemps et al. in 2012 offers a way to curb chocolate cravings through our sense of smell. In their experiment, they asked 67 female undergraduates between the ages of 18-35 to look at 30 images of 10 different kinds of chocolate food such as cakes, bars, and ice cream. Each image was shown for 5 seconds with a delay after the image. During the delay, participants continued to imagine the image they saw in an attempt to produce a cravings for it (Kemps et al., 2005). During the delay, the participant also smelled a bottle with the scent of water (the control), jasmine (a non-food smell), or green apple (a food smell), then rated their desire for chocolate. The data collected showed that when participants smelled jasmine, their desire for chocolate was at its lowest.

The teal area shows the cingulate cortex, activated by chocolate consumption during the experiment by Small et al. in 2001.

This study was the first of its kind to link non-food odors as a useful means of suppressing chocolate cravings, but what happened in the brains of these participants? Another study by Small et al. in 2001 analyzed the brain’s motivation to eat chocolate and found that the anterior cingulate cortex in the brain starts to becomes active when you take that first bite of chocolate and stays active even when you’ve eaten enough chocolate that it becomes averse. A different study by Small et al. in 1997 showed that stimulating both our taste and smell sensations activates limbic brain areas, which include the cingulate cortex mentioned above.

Some of many brain areas associated with chocolate eating, smelling, and motivation.

With these two studies in mind, how does all of this fit into the chocolate craving antidote discovered by Kemps et al.? If together smell and taste can activate the cingulate cortex and the anterior portion of the cingulate cortex is involved with our motivation to eat chocolate, then smelling a non-food smell like jasmine may be blocking something along that processing pathway between chocolate consumption and our motivation to each chocolate in the cingulate cortex.

Of course, this is just my own speculation. Kemps et al. did not go into further detail about why jasmine effect on the brain our desire to eat chocolate, if jasmine is the only odor with this effect on chocolate cravings, or if jasmine an suppress cravings for other foods. The study also focused on only one age group and one sex, therefore its results may not seem significant this field until other researchers conduct follow up research. Regardless, this still an intriguing study in how it offers a potential therapeutic for women who have problematic chocolate cravings or other eating disorders. Not only that, but maybe it could help people like me who simply don’t want to give up eating something that tastes so wonderful.

-Nicole Asante

Resources:

Kemps E, Tiggemann M, Bettany S (2012). Non-food odorants reduce chocolate cravings, Appetite 58(3):1087-1090.

Ried K, Sullivan T, Fakler P, Frank O, Stocks N (2010). Does chocolate reduce blood pressure? A meta-analysis, BMC Medicine 8(39).

D Small, Zatorre R, Dagher A, Evans A, Jones-Gotman M (2001). Changes in brain activity related to eating chocolate: From pleasure to aversion, Brain 124:1720-1733.

Small D, Jones-Gotman M, Zatorre R, Petrides M, Evans A (1997). Flavor processing, NeuroReport 8 (18):3913-3917.

http://bethycotter.wdfiles.com/local–files/cingulate-cortex/Screen%20Shot%202012-10-26%20at%202.31.57%20AM.png

5 Comments

Posted in Uncategorized

Tagged chocolate, neuroscience, Paris, Taste

Why put so much effort into learning a second language?

Posted on June 22, 2015 by Amy Ming-Lo Yeh | 6 comments

I have loved the study of French language since the day I started classes in 9^th grade. Even though Neuroscience is my primary major, my French second major has always been a passion and an outlet from core sciences. While this is my 3^rd time in Paris, I’ve (finally) noticed that fluency is coming more naturally, even when I’m flipping between conversations and homework in French to texts and Skype sessions in English. As a double major in French and Neuroscience, (naturally) I was interested in finding out how language development and the brain’s response are interconnected.

I have stayed with 3 homestays and lived in the Cité Universitaire over the past 5 years. [image souce: Google maps]

Over the past 5 years, I have stayed with 3 homestays and lived in the Cité Universitaire. [image souce: Google maps]

Paris is an ideal place to begin an inquiry into language and speech. The earliest roots can be attributed to the work pioneered here by Paul Broca, the French physician and anatomist, who studied the speech production centers of the brain – now termed Broca’s area.

I visited the brain Broca studied at Musée Dupuytren [image source: Google images]

Advances in technology not available to Broca in the 1800s allow us to use neuroimaging methods to reveal specific functional brain patterns in learning a second language. After doing some research on the effect of bilingualism on the brain, I think that what I’ve been experiencing in my studies abroad is likely an actual change in brain structure. A property known as plasticity is the ability of the brain to physically and functionally change in response to factors such as environmental stimuli or cognitive demand (Stein et al., 2010). This process occurs in everyone who learns or speaks a second language, which turns out to be over half the global population (Bialystok and Barac, 2013). Learning a language in addition to your native tongue induces these changes in the brain (Stein et al., 2010). While this process occurs regardless of age, the speed of plasticity directly correlates to the long-term proficiency of an individual (Stein et al., 2010). So, relative to the time I started learning French in 9^th grade, my immersion experience these last six months has allowed my brain to greatly pick up speed in making physical and functional changes compared to my 15-year-old self.

Not only is the study of French language a passion, being bilingual (or as close as I’ll ever get) advances cognitive control meaning that bilinguals develop better decision making and conflict mediation skills than monolinguals, according to the bilingual cognitive advantage hypothesis (Bialystok and Barac, 2013). This development results from a bilingual’s ability to better monitor life-long experience, cultural sensitivity, and mentally separate and switch between two languages (Stein et al., 2010).

A study in 2011 tested the impact of bilingualism on conflict monitoring and found that bilinguals not only resolve cognitive conflicts more efficiently (meaning with less neural input), but that their brain also better sorts and makes sense of conflicting input (Abutelabi et al, 2011). Using a group of 17 highly proficient German-Italian bilinguals and 14 Italian monolinguals, researchers studied the anterior cingulate cortex (ACC), the brain center involved with language control and monitoring conflicting information, through blood flow measurements in a functional magnetic resonance imaging (fMRI) scanner. Participants were then asked to perform language and non-language switching tasks. For the language-switching task, monolinguals were presented with a set of 32 different pictures and asked to produce a noun or a verb associated with the picture based on a color-coded system (red for nouns and green for verbs). Bilinguals were then shown these same pictures, but asked to describe the picture in either German or Italian, per another color-coded system (green for German and blue for Italian). Researchers found that ACC activity was significantly increased in bilinguals. For the non-language switching task, the participants were presented with a cross in the middle of the screen to fixate their line of sight during the entire trial. Five arrows then appeared in randomized order and direction and the participants were asked to identify the direction of the center arrow only.

A schematic of the visual task presented (Albutelabi et al., 2011).

Here, the bilinguals required less ACC activity while still outperforming monolinguals in accuracy. These results show that bilinguals are more efficitvely and efficiently able to distinguish the direction of the center arrow surrounded by the swtiching stimuli.

I loved that this study incorporated both a language switching task and a non-verbal task, which shows that the two tasks were carried out by the brain in the same region and thereby lends credit to the idea that development of the ACC in the study of a second language has positive effects in other parts of our daily lives. However, I wish that Albutelabi et al. had used participants of varying degrees of proficiency to see if the bilingual advantage spans across any second language learner.

Independent of my improved ability to find the best pastry in Paris due to increased language proficiency, I hope that I will have gained a life-long advantage to greater health and mental acuity. Not only have Paris and my French studies given me a greater awareness and appreciation of the world, increased neuroplasticity will allow me to use these now more refined areas, giving me confidence to switch between subjects and focus in on information relevant to the task at hand. This will come in particularly useful in my pre-dental studies along with other future endeavors, as lifelong bilingual experience may serve as a major deterrent to the onset of age-related cognitive decline (Grogan et al., 2012).

This semester, I shadowed a French general dentist in the 11th arrondissement.

As I end my time in this beautiful city, I will keep my experiences (and brand new brain) pour toujours.

~ Amy Yeh

References

Abutalebi J, Della Rosa PA, Green DW, Hernandez M, Scifo P, Keim R, Cappa SF, Costa A (2011) Bilingualism Tunes the Anterior Cingulate Cortex for Conflict Monitoring. Cerebral Cortex 22:2076–2086.

Bialystok, E., & Barac, R. (2013). The psycholinguistics of bilingualism. New York, NY: John Wiley & Sons, Inc.

Grogan A, Jones OP, Ali N, Crinion J, Orabona S, Mechias ML, Ramsden S, Green DW, Price CJ (2012). Structural correlates for lexical efficiency and number of languages in non-native speakers of English. Neuropsychologia 50(7): 1347-1352.

Stein M, Federspiel A, Koenig T, Wirth M, Strik W, Wiest R, Brandeis D, Dierks T (2010) Structural plasticity in the language system related to increased second language proficiency. Cortex 48:458-465.

6 Comments

Posted in Neuroscience

Tagged ACC, bilingual, fMRI, neuroplasticity, second language, task switching

Café au Lait to get Through the Day

Posted on June 22, 2015 by Ethan Siegel | 1 comment

My amazing “café au lait” from Coutume Café in the 7ème arrondissement

Who doesn’t love a nice, hot cup of coffee after a morning shower? Not only does it taste AMAZING, but it also wakes you up and gets you ready for the day to come. Every morning, for the last 4 or so years, I drink a cup of coffee while getting dressed or eating breakfast. So, upon coming to Paris, I undoubtedly continued my ritual.

The walk from Cité Universitaire (where I live) to Coutume Café (my favorite coffee shop).

I essentially used my love of coffee as an excuse to visit as many cafés and small restaurants as possible. However, I soon discovered the enormous difference between French coffee and the American coffee that I am used to. The French are huge advocates for espresso, that is, a coffee-like drink served in tiny porcelain cups. However, unlike American coffee, espresso is extremely potent and filled with a TON of caffeine. Over the past few weeks, I too have become a lover of espresso and the large amount of caffeine and “energy” that comes with it. However, I was not quite sure exactly how caffeine affects the brain resulting in what we perceive as a boost in energy and decrease in drowsiness. So, throughout my days in Paris, I looked for an answer.

Typical French coffee (left) vs. typical American coffee (right)

While searching for an answer, I stumbled upon an article by Lazarus et al. (2011) concerning the effects of caffeine on wakefulness. Previous research found that caffeine counteracts fatigue by binding to adenosine A2A receptors. Adenosine, an inhibitory neuromodulator, has been linked to regulation of the homeostatic sleep drive. So, by binding to the receptor in the brain that normally binds to adenosine, caffeine indirectly prevents adenosine from functioning properly, altering one’s sleep pattern (Huang et al., 2011). Lazarus et al. used this information to construct their experimentations.

In their study, Lazarus et al. bred a strain of rats that had a knockout of the A2A receptor in their nucleus accumbens, that is, these rats did not have this receptor within this specific brain region. They then performed EEG (electrical monitoring) tests on these rats and compared their electrical brain activity with that of control rats (rats that did not have the A2A knockout). The researchers administered equivalent concentrations of caffeine to both groups of rats and monitored their brain’s electrical activity during sleep cycles. What they found was extremely interesting. The caffeine caused increased wakefulness in the control rats (those that did not have the A2A receptor knockout), while caffeine had no effect on wakefulness in the experimental rats (those with the A2A receptor knockout). This means caffeine not only blocks adenosine from binding to the A2A receptor (Huang et al., 2011), but it also prevents the activation of the “adenosine break,” resulting in increased wakefulness.

A figure from Lazarus et al. (2011) depicting the adenosine A2A receptors in the nucleus accumbens of rat models. The left shows a control (wild-type) rat nucleus accumbens, while the right shows an experimental (knockout) rat nucleus accumbens.

Furthermore, the data from this study suggests that caffeine induces arousal and wakefulness by activating pathways in the nucleus accumbens that have formerly been associated with locomotion and motivational behaviors. This is a novel finding because it implicates caffeine in more than just the blocking of adenosine, but also in the activation of further neuronal circuitry, promoting a sense of “energy”.

A figure from Lazarus et al. showing the effect of caffeine on wakefulness. There is no significant increase in wakefulness in the A2A receptor knockout mice as more caffeine is administered. However, there is a significant increase in the wakefulness of wild-type mice as more caffeine is administered.

What I find super interesting about this study is how the researchers localized the antagonist effects of caffeine to the nucleus accumbems. In previous neuroscience classes, I learned of the association between the nucleus accumbens and cognitive processes such as motivation, pleasure and reward, thus implicating this brain region in numerous forms of addiction. With this in mind, I wish the experimenters had monitored the changes in behavior between the experimental and control rats when receiving differing levels of caffeine. This could be accomplished by using an intravenous self-administration task (IVSA). IVSA entails using chambers with small levers that, when pushed, cause specific drugs to be administered into the tail of that rat that pushed the lever (Figure 1). The researchers could perform IVSA for both control and experimental rats, and use either a saline or a caffeine solution as the respective drug. If this was done properly, I predict the control rats to show increased pushing of the lever when receiving caffeine compared to saline, corresponding to an greater feeling of pleasure and reward associated with the caffeine. Alternatively, I predict the experimental rats to show no significant difference in pushing of the lever between administrations of caffeine and saline because the caffeine does not affect their nucleus accumbens in the same way that it does for the control rats.

A very simplified version of the IVSA task in rat models.

Regardless, I find the study by Lazarus et al. to be extremely fascinating because, as a regular coffee drinker, it gives me insight to what is occurring in my brain!

Anyway, I’m about to go grab a coffee and walk around the city. Until next time!

~ Ethan Siegel

References:

Huang ZL, Urade Y, Hayaishi O (2011) The role of adenosine in the regulation of sleep. Curr Top Med Chem 11:1047–1057.

Lazarus M, Shen H-Y, Cherasse Y, Qu W-M, Huang Z-L, Bass C, Winsky-Sommerer R, Semba K, Fredholm B, Boison D, Hayaishi O, Urade Y, Chen J-F (2011) Arousal effect of caffeine depends on adenosine A2A receptors in the shell of the nucleus accumbens. The Journal of Neuroscience 31(27): 10067-10075

1 Comment

Posted in Uncategorized

Tagged Brain, caffeine, coffee, Energy, neuroscience, Paris, Sleep

The chocolate adventures of a chocolatier’s daughter in Paris

Posted on June 22, 2015 by Sasha Cukier | 4 comments

Chocolate. Chocolate. Chocolate. I can’t even begin to describe how much I love it. To give you guys a bit of context on my never-ending craving, my mom started a chocolate company while I was growing up. On a daily basis, my whole house smelt of freshly rolled truffles, baked brownies and chocolate cookies. Now, everywhere I go, I need to make sure that I have chocolate available at all times. In my Parisian dorm room, I have at least five chocolate bars in stock. The satisfactory feeling of biting into a creamy piece mid-essay is unbeatable.

Map of some of the best boulangeries in Paris

Walking around Paris, I love to stop at boulangeries and try whatever they have to offer, chocolate style. Some of my favorites so far include pain au chocolat, opera cake, and chocolate crepes. I recently spent the afternoon vising my brother and his wife in Belgium, and was in chocolate heaven. The Belgian chocolate brownie I had was life changing. My chocolate adventures continued this past Friday when I went to Le Musée Gourmand du Chocolat in Paris. It was quite the delicious experience; I indulged in cinnamon hot chocolate, praline, and other rare chocolates from all over the world. Best afternoon yet.

Me at Le Musée Gourmand du Chocolat

My current neuroscience mindset made me start to wonder how my chocolate cravings translate to brain activity. In a study by Frankort et al. the researchers studied the short-term effects of chocolate cravings on behavior, specifically how neuroimaging can predict chocolate consumption. The two different experimental groups consisted of participants who smelt chocolate and participants who didn’t, with 17 females in each group. They compared self-reported craving to brain activation showed by fMRI scans which measures the change in blood flow in different brain areas. Previous studies have found that prolonged chocolate exposure, like the chocolate scent group, leads to a decrease in craving. This effect was not observed in the Frankort et al. study; perhaps because the fMRI scan interrupted the 1-hour scent exposure sessions, which displays a weakness of the study since the interruptions don’t accurately model a real life situation.

Brain activation in areas correlated with chocolate intake. Green: whole group anterior PFC activation, Yellow: exposed group caudate and frontopolar cortex activation, Purple: control group dorsolateral PFC and mid-dorsolateral PFC reduced activation.

Primarily, Frankort et al. found that neural activation in the right caudate and the left lateral frontopolar cortex predicted chocolate intake in the exposure group. The left lateral frontopolar cortex and the right caudate are both associated with reward and memory (Pochon et al. 2002), which explains the chocolate consumption. Furthermore, the left dorsolateral and mid-dorsolateral prefrontal cortex (PFC) correlated negatively with consumption in the control group, meaning the activation predicted decreased intake. These findings make sense since this area is associated with cognitive control (I would guess that I don’t have a very active left and mid-dorsolateral PFC when it comes to chocolate consumption). In both groups, the right anterior PFC, activation was associated with chocolate intake. This region is associated with cognitive behavior, planning and decision making (Wikipedia).

These regions of activation represent a better measure of future chocolate intake than self-reported craving, meaning that my brain knows I’m going to crave chocolate better than I am consciously aware of! The most surprising fact from this study was that overall self-reported chocolate craving did not correlate with intake. Meaning, just because I think I crave chocolate doesn’t mean I necessarily crave it. To really know if I crave something I would have to check my brain scans! A significant weakness of this study was how craving was measured by asking participants one question. Future studies should include a more appropriate measure of craving with multiple questions, since just having one may not fully explain the results.

This newfound knowledge on self reported craving has definitely made me rethink my chocolate consumption. Is a craving really a craving without brain activation? Whatever the answer to this question, I’m going to eat all the chocolate I can in this last week! Maybe I should rename the program title to Neuroscience, Chocolate and Paris.

Me eating un pain au chocolat

Me eating a chocolate cake

-Sasha

References:

Frankort A, Roefs A, Siep N, Roebroeck A, Havermans R, Jansen A. (2015) Neural predictors of chocolate intake following chocolate exposure. Appetite. 87:98-107

Pochon JB, Levy R, Fossati P, Lehericy S, Poline JB, Pillon B, Le Bihan D, Dubois B (2002) The neural system that bridges reward and cognition in humans. An fMRI study. Proceedings of the National Academy of Sciences of the United States of America. 99: 5669–5674

Map: http://www.quora.com/What-are-the-best-boulangeries-and-patisseries-in-Paris-for-each-arrondissement

https://en.wikipedia.org/wiki/Prefrontal_cortex

4 Comments

Posted in Neuroscience

Tagged chocolate, MRI, neuroscience, Paris, PFC

Walking through Paris

Posted on June 22, 2015 by Celia Greenlaw | 2 comments

Amongst the many changes I have experienced while in Paris, I noticed that I am walking considerably more than I usually do. While most people are aware of the positive impact walking and exercise can have on the body, I am dedicating this post to exploring the effects of exercise on the brain.

Thanks to my handy Fitbit (yes, I know I am a little obsessed), I am able to track my daily activity, so I have a very good idea about how much exercise I am getting. Between going to class, touring museums, and exploring getting lost in the streets of Paris, I am walking an average of over 8 miles every day. Paris is a very “walk-able” city, and my friends and I regularly opt to walk to our destinations instead of using the metro. I know that this must be affecting my cognitive ability, because even while operating on 4-6 hours of sleep every night, I am able to focus and work surprisingly well.

Fitbit evidence that 1) I am walking crazy amounts in Paris, and 2) I can justify eating multiple pastries a day* *point 2 has not been scientifically proven

Fitbit evidence that 1) I am walking crazy amounts in Paris 2) I can justify eating multiple pastries a day*
*point 2 has not been scientifically proven

A recent study in college-aged females found that after only a single session of moderate exercise, participants showed increased brain activation during a working memory task (Li et al. 2014). Working memory is a limited brain resource that temporarily stores, processes and updates action-related thinking. It is utilized when you need to actively handle information, and your working memory capacity is an important measure of cognitive function. The researchers in this study used a modified N-back task to measure working memory. This task requires participants to attend to a sequence of stimuli, and determine if the current stimulus matches a stimulus that was “N” steps earlier in the sequence. The task gets more and more difficult as N increases, because it becomes harder to keep track of when a stimulus appeared.

A visual representation of the N-back task used in the study by Li et al. (2014)

To compare brain function, the subjects performed this task while in a functional magnetic resonance imaging (fMRI) machine, once following exercise, and once following a rest period. The fMRI measures blood oxygenation, which provides a visual image of brain activation. While there was no significant change in subject performance on the task, the data show more brain activation in the exercise condition, especially in the prefrontal cortex (PFC) and medial occipital cortex during the 2-back condition. The PFC is well recognized to be important for working memory, and the specific areas of the occipital lobe that changed are also involved in online processing. The lack of performance change limits the conclusions that can be drawn from this study, but it is reasonable for me to assume that my working memory capacity is positively influenced by the increased exercise I get in Paris. The researchers clearly showed that exercise influenced the brain areas important for working memory in subjects of my same age and sex, and this effect would likely be enhanced by an extended exercise routine like mine. A future study could explore the effect of chronic exercise, or use multiple behavioral measures to see if that leads to more pronounced changes in working memory performance.

Working memory is not the only brain function influenced by exercise. In fact, hundreds of studies explore how exercise can change the brain. One of the most common focus areas is how exercise increases brain-derived neurotropic factor (BDNF) in the hippocampus. BDNF is very important for brain plasticity, and the hippocampus is highly involved in learning and memory. One study found that exercise enhanced memory and cognition in rats, through the action of BDNF and the pathways it influences (Vaynman, et al. 2004). A different study focused on the non-neuronal cells in the brain, called glial cells (Brockett, et al. 2015). They found that running influenced synaptic plasticity in rats, producing widespread positive effects in both neurons and glial cells in areas associated with cognitive improvement. The last study looked at showed how exercise can help people’s mental health by reducing the stress hormone cortisol, through overall regulation of the hypothalamic-pituitary (HPA) axis (Zschucke et al. 2015).

I walked almost 10 miles before stumbling upon this set at Fete de la musique, and the journey was as fun as the event!

It is so interesting to hypothesize about the different ways that my brain may be changing in response to something as simple as walking. Evidence suggests that my working memory capacity, brain plasticity, and mental health are all influenced by exercise. Now that I only have one week left to enjoy Paris, I will make sure to walk everywhere to experience, learn and improve my brain as much as possible. With all of the positive effects Paris seems to have, I know I will be planning a return trip the second I get home!

References

Brockett AT, LaMarca EA, Gould E (2015). Physical Exercise Enhances Cognitive Flexibility as Well as Astrocytic and Synaptic Markers in the Medial Prefrontal Cortex. PLoS ONE. 10(5): e0124859.

Li L, Men W-W, Chang Y-K, Fan M-X, Ji L, & Wei GX, (2014). Acute Aerobic Exercise Increases Cortical Activity during Working Memory: A Functional MRI Study in Female College Students. PLoS ONE. 9(6): e99222.

Vaynman S, Ying Z, and Gomez-Pinilla F, (2004). Hippocampal BDNF mediates the efficacy of exercise on synaptic plasticity and cognition. European Journal of Neuroscience. 20: 2580–2590.

Zschyke E, Renneberg B, Dimeo F, Wüstenberg T, & Ströhle A (2015). The stress-buffering effect of acute exercise: Evidence for HPA axis negative feedback. Psychoneuroendocrinology. 51: 414-425.

2 Comments

Posted in Uncategorized

Tagged BDNF, cognition, exercise, fMRI, HPA-axis, neuroscience, Paris, working memory

The Nose Knows

Posted on June 22, 2015 by Kimi Chan | 3 comments

Hi Friends!

There are so many scents in Paris that I can talk about, ranging from lovely floral fragrances to freshly baked baguettes in patisseries. My olfactory (another word for smell) senses are overwhelmed with all the new odors that I’m exposed to! Last week, during a class excursion, we went to the Fragonard Fragrance Museum. We got to tour the museum and learn about the history of fragrance. Apparently back in ancient times, they used fragrance to preserve the dead so that the people could mourn the bodies during ceremonies. It’s bizarre to think how much the usage of fragrance has changed since the beginning of time! Now the perfume industry is all about making yourself appear attractive. When I was at Fragonard, my favorite perfume scents were floral mixed with fruity. It was an exciting experience to find the perfect perfume for myself (and my family) and it was extremely fun to try to distinguish all the different scents. I learned from one of my classes here that the human olfactory system can distinguish more than a trillion olfactory stimuli (Bushdid, 2014). One trillion?! That’s a ton of different smells!

I got these three perfumes at the Fragonard Museum for me and my family! Hopefully we all smell nice 🙂

Even though there are many pleasant scents here, I also found some that are cringe-worthy. For example, I noticed that many Europeans smoke cigarettes and the streets are constantly polluted with people smoking. Cute bistros will have tables outside where people smoke, which makes my dining experience quite unpleasant when I’m eating in a haze of smoke. I guess I am never really exposed to this much smoking in the states, so I spent the first couple of weeks here adjusting to the smell of cigarettes. After thinking about all these pleasant and unpleasant smells, I started to wonder…how does this relate to neuroscience? Surely my field of study can explain how my olfactory senses adjust to unpleasant smells!

Typical tables outside of a French bistro. This is my favorite one called Bistrot d’Edmond!

In a study done by Ferdenzi et al. in 2014, the researchers found that repeated exposure to odors induces “affective habituation” of perception and sniffing. “Affective habituation” was a phenomenon described by Cain and Johnson in 1978 that states repeated exposure to a scent shifts odor pleasantness ratings toward neutrality. In other words, this theory says that we will start to like a pleasant smell less and feel more neutral to it if we are exposed to it repeatedly. Cain and Johnson’s “affective habituation” phenomenon happens with unpleasant smells, too. Previous studies, however, only focused on self-reported ratings and did not investigate variations of physiological responses among individuals. Thus, Ferdenzi et al. aimed to analyze both self-reported ratings and changes in sniffing patterns to pleasant and unpleasant smells.

Ferdenzi et al. first recruited twenty-six young adults at a French university (what a coincidence this study was done in France!). The researchers split these people up into two groups – the “likers” and the “dislikers” when presented with an odor such as chocolate. They kept track of these groups and repeated this step with 8 different odors through a nasal mask. The “olfactometer” was connected to a nasal mask and measured how much each person breathed, which calculated the levels of sniffing. Lastly, study participants were instructed to rank how pleasant each smell was on a computer.

This picture shows the experimental device and how study participants would wear a nasal mask in order to smell the odor and rank its pleasantness.

Ferdenzi et al. found that pleasantness significantly decreased with time in “likers” while unpleasantness tended to decrease with time in “dislikers.” Increase in sniffing also correlated to a shift in greater pleasantness ratings, meaning that people would sniff more when they were repeatedly presented with an unpleasant smell. In general, their findings support the “affective habituation” hypothesis both at the self-reported level and at the olfactomotor level. This is interesting because I find this to be congruent with my life experiences. I notice that I find an unpleasant smell less aversive when I’m repeatedly exposed to it. However, I wonder if 26 young adults is a representative sample of the general population. I wish they had more test subjects and an equal amount of males and females in this study so that the researchers can have a more comprehensive analysis. Previous research has shown that females have better odor identification abilities than males (Doty et al., 1985). I wonder what the results would have been if they had an equal number of males and females.

I now understand why I am becoming more immune to the strong smell of cigarettes here in Paris. Affective habituation and neuroscience can definitely help explain this weird phenomenon! Maybe one day I’ll get accustomed to the pungent smell of body odor on the metro (ha ha!). Let’s just hope that people will wear deodorants on hot days so that I don’t have to deal with smelling and feeling body sweat on the train (eek!). I hope you enjoyed this blog post about smell and neuroscience. Sending love from Paris! 🙂

-Kimi

References

Bushdid C, Magnasco MO, Vosshall LB, Keller A (2014) Humans Can Discriminate More than 1 Trillion Olfactory Stimuli. Science 343: 1370-1372.

Cain WS, Johnson F Jr (1978) Lability of odor pleasantness: influence of mere exposure. Perception 7(4):459-65.

Doty R, Applebaum S, Zusho H, Settle R (1985) Sex differences in odor identification ability: A cross-cultural analysis. Neuropsychologia 23(5)667-672.

Ferdenzi C, Poncelet J, Rouby C, and Bensafi M (2014) Repeated exposure to odors induces affective habituation of perception and sniffing. Front Behav Neurosci 8:119.

3 Comments

Posted in Neuroscience

Puppies in Paris*

Posted on June 22, 2015 by Megan Louise Airey | 2 comments

*Title credit goes to Rachel Cliburn for her initial “Pooches of Paris” idea

Dear fellow readers,

I cannot believe this is my last week in Paris. The time has flown by. I can’t believe how much I’ve learned, the amazing people that I’ve met, and what I’ve been able to explore in Paris as well. As I spent some time the past few days reflecting on my time abroad these past five weeks, I couldn’t help but think about how my experience and life at home has shaped my experience here, especially since I got to spend a week of my trip with my mom.

My mom and I at Sacre Coeur in Montmartre, located at the 18th arrondissement in Paris

But while I wandered the streets of Paris, whether it be near the Accent center where we have class, on the Metro, or near Cité Universitaire where we live, I couldn’t help myself noticing all the different animals that freely roam about Paris, especially dogs. Most people who know me and know me well know how attached I am to different animals; however, none compare to how much I love dogs. I’ve seen them here and there around Paris: from a pleasantly plump pug to a shaggy, content mutt, I’ve taken note and even snapped a few pictures!

A black pug seen across the street from Accent (although not a great picture)

Spotted: An adorable mutt seen on the Metro (pun intended). My mom called this dog my brother’s “doggleganger”, since they both have two different colored eyes. 🙂

I had the pleasure of growing up with two Newfoundland dogs. If you aren’t familiar with the breed, Newfoundlands are typically very big, black dogs that originate from the coast of Canada. My first dog, Rufus, was a darling: quite a sweetheart and lived with me until I was about 8 years old. After he died of a brain tumor, my family got another dog named Angus. Same breed, but quite a different animal entirely. Angus was rambunctious and always quite a joker: he used to eat our socks (which we’d later find mixed in with his poop in the backyard a day or so later)!

But we all loved Angus. Up until he passed away in 2013, he was one of the most important parts of my life.

Angus and me reunited during fall break of my first year of college (2012)

After seeing various puppies around Paris, I thought back to Angus and just how important he was to me. These thoughts made me wonder: do our canine counterparts feel similarly attached to us as we do to them?

After some researching, I stumbled upon a study that looked into attachment behavior in dogs. This study applied Ainsworth (1969)’s original Strange Situation Procedure to attachment behavior in dogs! For those of you who aren’t familiar with Ainsworth’s Strange Situation Procedure, this paradigm consists of separations and reunions between parent and child and is used to assess degrees of attachment. The paradigm can be broken up into three stages:

1. Child enters a room with their parent/guardian (usually the child’s mother) filled with toys and a stranger whom the child has never met before. The child is allowed to explore/play with the toys in the presence of both the stranger and his or her parent.

2. The mother leaves the room, leaving the child alone with the stranger (and the toys).

3. Third, the mother re-enters the room and re-joins the child with the stranger.

The child’s behavior is observed during each of these stages to assess the level of attachment the child has towards his or her parent. If the child has a “secure” attachment to their parent, they will likely be upset when the mother leaves, but quickly soothed upon her return. An “insecure avoidant” child will not be phased by the mother’s initial presence, absence, or return, and will likely ignore the parent throughout all stages. An “insecure anxious” child will be so distraught by the parent leaving the room that they are often inconsolable, even upon the parent’s return. Lastly, a “disorganized” child exhibits strange behavior that does not fit into any of the above categories.

To better understand this procedure, here’s a video example:

So you can imagine my excitement when I found out that they did a similar study with dogs! In Topál et al. (1998), they modeled this strange situation procedure with a series of separations and reunions in 51 dog-owner pairs. And do you know what they found? Adult dogs show patterns of attachment toward their owners! The observed dog behaviors are also similar to the mother-infant interactions recorded during Ainsworth’s original study. Additionally, another study by Zilcha-Mano, Mikulincer, and Shaver (2011) found that individual differences in human attachment to pets results in pet-related cognitions, emotions, and behavior. This study also illustrated these differences lead to different emotional reactions to the death of the pet. No wonder my attachment to Angus resulted in so much grief when he passed!

After reading Topál et al.‘s research findings, I’d be curious to know at what point during the dog’s life this attachment emerges. In humans, attachment develops fairly early. This study was only done in adult dogs, and the researchers also admitted to having considerable variability in dog behavior. Additionally, I wonder if abused dogs would show “insecure avoidant” behavior, as abused children often do.

For the moment though, it does appear as if my attachment to Angus probably wasn’t only one-sided. I wonder if he misses me as much as I miss him!

Me and Angus in 2005

Here’s hoping that all the Parisian puppies out there have good and kind owners, and that they can develop an emotional attachment as special as mine and Angus’s was.

Au revoir pour le moment lecteurs!

Meg

References:

Ainsworth, M. D. S., Wittig, B. A. (1969). Attachment and exploratory behavior of one-year-olds in a strange situation. Determinants of Infant Behavior, 4, 113–136.

Topál J, Miklósi Á, Csányi V, Dóka A (1998). Attachment Behavior in Dogs (Canis familiaris): A New Application of Ainsworth’s (1996) Strange Situation Test. Journal of Comparative Psychology. 112: 219-229.

Zilcha-Mano S, Mikulincer M, Shaver PR (2011). An attachment perspective on human-pet relationships: Conceptualization and assessment of pet attachment orientations. Journal of Research in Personality. 45 (4): 345-357.

2 Comments

Posted in Neuroscience

Tagged dog attachment to humans, strange situation procedure

Sugar, Parisian Sights, and Group Runs are Nice

Posted on June 8, 2015 by Beatrice Secheli | 4 comments

Bonjour family and friends,

When I first arrived in Paris two weeks ago, I was excited to find so many active Parisians running and biking everywhere! Walking around the Cité Universitaire residential campus, I am often startled by a breathless “Pardon!” (Pardon me!) as a runner passes by on my left. Also, more than 20,000 bikes are available for rent in Paris through Vélib’ for €1.70 per day (visit http://en.velib.paris.fr/How-it-works/Bikes). My Paris bucket list definitely includes trading my metro pass for a bike for at least one day in the upcoming three weeks.

Vélib’ public bicycle sharing system

One of my professors, Dr. Jacob, and our TA, Rachel, lead group runs in parks around Paris. I ran my first half marathon this past March in Atlanta and wanted to continue running and exercising while in Paris. Running is a great opportunity for sightseeing and exploring beautiful, natural spaces such as parks, gardens, and riverbanks.

Rachel and I spreading our wings toward the birdhouse carvings in the tree!

Running also helps work up a healthy appetite…Lucky for me, there’s a boulangerie (bakery) on the corner of each street!

During the hour-long lunch break between my two neuroscience courses, I usually orient myself towards a boulangerie for lunch. Nearly every boulangerie’s Formule Dejeneur (or Lunch Formula) includes a sandwich, drink, and dessert that’s almost too pretty to eat. With so many boulangeries and crêpe stands as far as the eye can see, Paris must be every sugar addict’s heaven on earth. However, such easy access to desserts makes me wonder about the current diabetes rate in France. Also, I wonder in what way physical exercise, such as running and biking, can affect a diabetes patient’s brain. After some online research, I found a few neuroscience explanations to satisfy my curiosities (for now).

Sample lunch formula

Tarte au Citron (Lemon Tart) – Is your mouth watering yet?

First of all, diabetes is a disease in which high blood sugar levels exist over a long period of time. I personally know a few individuals who are pre-diabetic and have to carefully monitor the sugars they consume. Drawing from a research study published today (6/8/2015) in The Lancet, a British medical journal, diabetes occurrence increased 45% from 1990 to 2013 (Global Burden of Disease Study 2013 Collaborators, 2015). In France, 7.2% of adults (20-79 years old) suffer from diabetes. This percentage represented about 3,241,300 diabetes cases last year in 2014 (visit https://www.idf.org/membership/eur/france).

Diabetes, specifically diabetes mellitus, directly relates to neuroscience because this disease decreases brain function and leads to neurodegenerative diseases (Yi, 2015). In a research study hot off the press (5/22/2015), Nunes de Sena et al. investigated the effect of treadmill training on the brain function of diabetic rats. They divided sixty rats into four groups, with exactly fifteen rats in each group.

Group one included non-trained, healthy rats.
Group two included trained, healthy rats.
Group three included non-trained, diabetic rats.
Group four included trained, diabetic rats.

Based on this experimental break down, half of the rats received a chemical injection (streptozotocin) that led to diabetes over the course of thirty days and symptoms of hyperglycemia and body weight loss throughout the experiment. After thirty days, the exercise (“trained”) groups underwent five weeks of running training on a treadmill apparatus.

Could you imagine seeing this runner training at the gym?

On the day after the last training session, all of the rats participated in a short-term memory test, known as the Novel Object-Recognition Test (NOR). Rats were placed at the center of an open field apparatus (a.k.a. box) and given three minutes to explore their new environment. (This acclimatization period reminds me of the first few days after our arrival in Paris. We also landed in a new environment that we needed to adjust to before beginning coursework.) After the initial three-minute exploration time interval, testing included two five-minute trials. In the first trial (T1), the researchers placed two different objects inside the testing box. In the second trial (T2) one hour later, a new object replaced one of the objects from the first trial. The objects were as different as they could be! They differed in shape, surface, color, contrast, and texture. The researchers recorded the amount of time the rats spent exploring the new object and divided by the amount of time the rats spent exploring both objects, to check for any object preference. In terms of results, both of the exercise groups exhibited a stronger preference for the novel object. Thus, the researchers concluded that treadmill running improved short-term memory performance in both healthy and diabetic rats. I am not entirely convinced, however, based on results from one memory task. In order to establish a stronger connection between running and short-term memory, I think multiple, diverse memory tasks should be carried out. Overall, this paper is significant due to a major strength in the design of the research study: for the first time, researchers used diabetic rats to show that exercise improves performance in a non-spatial memory task. I am highly interested in reading future studies regarding the effects of exercise on other components of brain function in diabetic rats! Hopefully, such studies will contribute to more naturopathic treatments for pre-diabetic and diabetic patients.

With so many picturesque gardens, parks, and the Seine River, Paris provides countless opportunities for running. Even if you have normal blood sugar levels, what are you waiting for? Explore as you run!

À bientôt,

Beatrice

References

Bill F, Foundation MG (2015) Articles Global, regional, and national incidence, prevalence, and years lived with disability for 301 acute and chronic diseases and injuries in 188 countries, 1990 – 2013 : a systematic analysis for the Global Burden of Disease Study 2013. 6736:1990–2013.

De Senna PN, Xavier LL, Bagatini PB, Saur L, Galland F, Zanotto C, Bernardi C, Nardin P, Gonçalves CA, Achaval M (2015) Physical training improves non-spatial memory, locomotor skills and the blood brain barrier in diabetic rats. Brain Res: 1–8 Available at: http://www.ncbi.nlm.nih.gov/pubmed/26032744 [Accessed June 7, 2015].

Yi SS (2015) Effects of exercise on brain functions in diabetic animal models. World J Diabetes 6:583–597 Available at: http://www.ncbi.nlm.nih.gov/pubmed/25987956 [Accessed May 21, 2015].

All images were obtained through a Google image search, besides the image of Rachel and I in the park and the image of the Tarte au Citron.

4 Comments

Posted in Neuroscience

Tagged diabetes, exercise, Memory, running

Monthly Archives: June 2015

Less Work, More Play!

A Creature of “Habit”

Twenty-one and trying to keep it sober

Why put so much effort into learning a second language?

Café au Lait to get Through the Day

The chocolate adventures of a chocolatier’s daughter in Paris

Walking through Paris

The Nose Knows

Puppies in Paris*

Sugar, Parisian Sights, and Group Runs are Nice

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