Author Archives: Beatrice Secheli

A Day Just for Music

Posted on June 22, 2015 | 4 comments

Dear family and friends,

Imagine a day in Paris dedicated to music – voilà, Fête de la Musique!

My friends and I decided to first explore the music scene in the Saint Michel-Notre Dame area, one of our favorite parts of Paris (see map below). As soon as we emerged from the underground metro station near the Saint Michel Fountain, we heard a lively cacophony of sounds from every direction. Immediately, my appreciation for jazz music pulled me towards a jazzy trio on Rue Serpente. After they concluded their piece, I felt compelled to keep moving and enjoying as much music as possible. Further along, at the intersection of Rue Serpente with Rue Hautefeuille, we bumped into a crowd of spectators swaying to a soft rock band and our faces instantly brightened with auditory pleasure. Earlier in the day, I felt stressed by schoolwork and my upcoming departure from Paris, but I was beginning to notably relax upon joining the musical festivities.

Fete de la Musique Map

While I was absorbed in the drum rhythms of another music group – I even watched a dance-off between a young girl and a grown man! – I considered the ways in which music was positively impacting my mental state (see image below). But the neuroscientist in me also wondered, what happens at the neurobiological level?

danceoff                                                                        Dance-off

After some internet research, I chose a study by Sheikhi and Saboory examining the impact of musical stimuli on the rat brain, because the study was uniquely conducted during the fetal period. Isn’t that incredible? Previous studies have identified the connection between environmental factors and prenatal development, demonstrating how sensory and motor stimuli entering the central nervous system can lead to neuroplasticity changes in neurons (Mathies et al., 2013). Neuroplasticity refers to changes in neural pathways and synapses. Specifically, stimuli can cause an increase in synaptic connections in the brain (Pirulli et al., 2013). In the fetal brain, other studies have examined the fetal response to music (Gerhardt et al., 2000). In this particular study, Sheikhi and Saboory examined neuroplasticity and neuronal cell density in the parietal cortex (see image below) of the fetal rat brain that was exposed to music as part of a prenatal model.

As part of the methodology, the researchers utilized twelve female Wistar rats (see image below) and followed ethical guidelines established by the Medical Ethics Committee of Iran. (Ethics boards encourage researchers to use the lowest number of rats and cause the least amount of pain possible!) At twelve weeks, the researchers mated the female rats and then divided pregnant rats into a control group and a musical group. Thus, each group included six pregnant rats. Twice per day, from day 2-20 of gestation, researchers exposed the musical group to classical music. However, they did not expose the control group to music. Before labor could occur on the 21st day of gestation, the researchers anesthetized the pregnant rats and collected blood samples from them. Sheikhi and Saboory removed the fetuses and randomly chose one fetus from each mother for brain dissection. Then, the researchers horizontally sliced the parietal cortex and examined the slices via an electron microscope. Returning to the blood samples collected from the pregnant rats, Sheikhi and Saboory measured corticosterone (COS) levels in each blood sample. Corticosterone refers to a hormone secreted by the adrenal cortex in rodents (see image below). COS protects against stress, in a similar way to cortisol in humans.

Wistar rat                                                                        Wistar rat

parietal_lobe                        The parietal cortex is located in the yellow region of this brain.

rat body

                             The adrenal cortex is the outer part of the adrenal gland.

Sheikhi and Saboory found that control rats exhibited simpler and smoother cells, while the music-treated group exhibited a more complex cell membrane and cytoplasmic organelles, which are the specialized structures inside of cells. Alternatively, the intercellular space, or the space between cells, displayed a greater density of structures in music-treated rats than in control rats. To determine the effect of prenatal music on the density of parietal cortical cells, researchers counted the number of nuclei in one electron microscope field, since each cell should theoretically have one nucleus. As expected, researchers found a greater cell density in the parietal cortex of music-treated rats than in control rats. Additionally, prenatal music helped to reduce COS blood levels in pregnant rats. Aha! I bet that a decrease in my cortisol levels is one of the reasons why I felt so relaxed during Fête de la Musique.

I believe the prenatal music model is a unique strength in study design and the findings can be related to an intra-uterine musical effect. However, I would like to offer a few of my own criticisms and suggestions for future experiments. According to the methodology, researchers only collected blood samples on the 21st day of gestation, and then claimed to see a reduction in COS blood levels. However, in order to draw comparisons, the researchers should have collected at least one other blood sample on the 1st day of gestation. Preferably, Sheikhi and Saboory should also have drawn blood from the pregnant rats at various, controlled time points throughout the experiment for stronger comparisons. In this research study, researchers exposed pregnant rats to only classical music, but I wonder if results would change with exposure to different types of music, such as jazz or soft rock. In a future experiment, Sheikhi and Saboory could also test the effect of music on rat infants immediately following birth. Additionally, the researchers only examined the fetal parietal cortex, but should examine other cortical areas as well.

– Beatrice

References

Gerhardt KJ, Abrams RM (2000) The Fetus Fetal Exposures to Sound and Vibroacoustic Stimulation. Journal of Perinatology 20:S20-S29 Available at: http://www.ncbi.nlm.nih.gov/pubmed/11190697 [Accessed June 22, 2015].

Matthies U, Balog J, Lehmann K (2013) Temporally coherent visual stimuli boost ocular dominance plasticity. J Neurosci 33:11774–11778 Available at: http://www.ncbi.nlm.nih.gov/pubmed/23864666 [Accessed June 22, 2015].

Pirulli C, Fertonani A, Miniussi C (2013) The role of timing in the induction of neuromodulation in perceptual learning by transcranial electric stimulation. Brain Stimul 6:683–689 Available at: http://www.ncbi.nlm.nih.gov/pubmed/23369505 [Accessed June 22, 2015].

Sheikhi S, Ph D, Saboory E, Ph D (2015) Neuroplasticity Changes of Rat Brain by Musical Stimuli during Fetal Period. 16:448–455 [Accessed June 22, 2015].

*I photographed the rock band and drum group, and found the other images through Google Maps and Images.

4 Comments

Posted in Uncategorized

Tagged , , ,

Sugar, Parisian Sights, and Group Runs are Nice

Posted on June 8, 2015 | 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.

Velib

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.

park run

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).

Formule Dejeuner

Sample lunch formula

 

Tarte au Citron

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.

rat on treadmill

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 , , ,