Entries in brain (10)

Wednesday
Nov232016

The science behind the food coma

Tomorrow is Thanksgiving, a day of family, football, and feasting! Following a large meal, many people experience what is known colloquially as a “food coma”.

Recently, scientists from the Scripps Research Institute, Florida Atlantic University, and Bowling Green State University may have found a reason for the phenomenon of postprandial sleep.  William Ja and colleagues used Drosophila (fruit flies) as a model to investigate the effects of eating on sleep. They found that after a meal, flies increased sleep for a short period before returning to a normal state of alertness. Flies that ate more also slept more. Protein, salt, and the amount eaten increased sleep, but sugar had no effect.

Researchers also used genetic tools to turn on and off neurons in the fly brain and identified a number of brain circuits that play a role in controlling post-meal sleepiness. Some of these respond specifically to protein consumption, while others are sensitive to the fruit fly’s circadian rhythms.

While this study was in fruit flies, there are some parallels and connections to mammals. Researchers speculate that post-meal sleep is important, perhaps for boosting digestion or helping animals form memories about a food source.

I wish you and your family a Happy Thanksgiving! Hopefully the “food coma” won’t hit too hard. 

CJW

References:

Scripps Research Institute. “Scientists Find Surprising Answers to ‘Food Coma’ Conundrum.” NeuroscienceNews. NeuroscienceNews, 22 November 2016.
http://neurosciencenews.com/food-coma-neuroscience-5578/

“Postprandial sleep mechanics in Drosophila” by Keith R Murphy, Sonali A Deshpande, Maria E Yurgel, James P Quinn, Jennifer L Weissbach, Alex C Keene, Ken Dawson-Scully, Robert Huber, Seth M Tomchik, and William W Ja in eLife. Published online November 22 2016 doi:10.7554/eLife.19334

 

Tuesday
Jul192016

Brains Understanding Computers Understanding Brains

“Computers aren’t smart.”  That’s the first thing my professor said on the first day of in Intro to Computer Science. “They’re dumb, but they’re fast,” he added.  At first I couldn’t believe what my professor was saying.  Computers seem to be quite intelligent.  IBM’s Watson could compete with Jeopardy! champions.  Need to know the answer to a question?  Just type it into Google.  Over the last few years, as I’ve learned more about computer science, I’ve come to learn that what my professor said on that first day of class is absolutely true.
In order to work, computers require extremely specific and detailed instructions laid out in a code they can understand.  Leave out a semicolon at the end of a line?  Forget it.  The computer will stop working.  A computer is nothing without a human brain to help it along.
The real value to a computer, of course, is its speed.  Today, an average laptop can carry out over a billion instructions in just one second.  Need to add up a million numbers in a spreadsheet?  Today’s computers can do so instantly.  Today’s computers can analyze massive amounts of data in very short amounts of time.
This is welcome feature for researchers studying the brain.  A single brain scan today can generate several gigabytes of data.  Even 25 years ago, this was unthinkable [1].  With new projects like the US Government’s BRAIN Initiative, research centers across the country are generating more data on the human brain than ever before [2].  To analyze this data, researchers are working hard to develop new algorithms and computational techniques.  Many scientists have expressed how important it is to train new researchers in the science of “big data” if we are ever going to truly understand how the brain works [3], [4].
The “big data” methods being used to better understand the human brain are the same that determine which advertisements show up in your web browser; the same that help Google decide what you’re searching for; the same that stock brokers use on Wall Street; and the same that the NSA controversially uses to “protect” sensitive American communications.
With big data, computers are starting to look like they might actually be smarter than humans.  But this isn’t true.  Without a human brain to ask the right questions and interpret the results, big data algorithms are worthless.  Rather, humans and computers are beginning to form a symbiotic relationship.  We use computers to speed up our own mental processing.  And now in neuroscience, we use computers and the artificial intelligence we have given them, to better understand our own intelligence, and our own minds.
- TMM
[1] https://en.wikipedia.org/wiki/History_of_hard_disk_drives
[2] http://www.braininitiative.nih.gov/index.htm
[3] Sukel, K. “Big Data and the Brain: Peaking at the Future of Neuroscience.” BrainFacts.org, 8 Dec 2015. Web.
[4] Van Horn, JD. “Opinion: Big data biomedicine offers big higher education opportunities. Proc Natl Acad Sci USA, 7 June 2016:113(23):6322-4 doi: 10.1073/pnas/1607582113.

 

Tuesday
Dec152015

An open mind for improving human health

‘Astounding’ is how I would describe the results presented by Dr. Roland Griffiths (a 40+ year veteran researcher at Johns Hopkins University School of Medicine) at the closing sessions of the 54th annual meeting of the American College of Neuropsycho-pharmacology.  Dr. Griffith and his colleagues shared study results that after a single treatment with the study drug, the severely depressed mood of terminally-ill cancer patients had been dramatically improved (and I would wager this as an understatement). Their perspective on life had been powerfully changed for the better and was evidenced not only on the way the patients felt about themselves but also from the feedback of members of the patients’ individual communities – the patients seemed much happier and more at peace to family, loved-ones, co-workers and community.  Even more incredible was that these positive changes were not only profound in magnitude, but remained very strong, even 6 MONTHS after treatment.  The effects seemed a bit like magic; the test drug was psilocybin – ‘magic mushrooms’.

Dr. Griffiths' landmark paper in 2006 remains a watershed in modern psilocybin research (http://www.ncbi.nlm.nih.gov/pubmed/16826400) and caused a resurgence of interest in the compound as a pharmacological tool that could be safely investigated in humans after a decades-long lag in research. The 2006 report, through a careful scientific approach, provided some of the best-controlled evidence for the positive and lasting effects of psilocybin in healthy volunteers. Highlights can be seen in his 2009 TEDxMidAtlantic talk, currently posted on YouTube.

Where had psilocybin gone? After widespread, and arguably fallible research (poor study design) in the 1950s and 1960s on then-legal psilocybin, concern of substance abuse as a street drug led to classification as a Schedule I drug in the US (high abuse potential with no accepted medical use). Psilocybin is a naturally occurring psychoactive compound produced by more than 200 types of mushrooms. Considered an ‘entheogen,’ it has been used for centuries in religious ceremonies to “generate the divine within” however its illegal status relegated it as an underground psychoactive drug, known also as ‘mushrooms’ or ‘shrooms’. 

Where has the anxiety gone? Whereas subjects in Dr. Griffiths studies emerged from treatment with a deeply positive recalibration of life’s meaning, a lead question during last week’s ACNP session was in the apparent absence of experiences occasioned by the lay user which are highly variable and dominated by feelings of intense panic and fear.  Here a key feature of Dr. Griffiths’ studies - ‘supportive conditions’  - are highly important and being with several visits between test subjects and study staff prior to psilocybin administration to develop trust and rapport. During the 8-hour psilocybin treatment session, study staff were present as ‘guides’ to reassure subjects and navigate darker experiences with greater confidence and a philosophy of discovery. 

Modern neuroscience has a close eye on this ancient drug, and beyond subjective mood testing, research led by Dr. Robin Carhart-Harris (Imperial College London) is using functional magnetic resonance imaging to better understand how brain activation patterns are modulated by psilocybin (http://www.ncbi.nlm.nih.gov/pubmed/22308440). In addition to the growing evidence from studies by Dr. Griffiths and similar trials at New York University (see a great article in the New Yorker from Feb. 2015; http://www.newyorker.com/magazine/2015/02/09/trip-treatment), the in vivo imaging results provide compelling evidence that under controlled conditions, psilocybin is safe and highly effective in improving the well-being patients in need. This is a fascinating example of science to me and I am excited to see how psilocybin’s status as an illegal drug with ‘no accepted medical use’ will change when the benefit to patients seems so clear.

 

-FAS

Photo credit: RollingStone.com

Media links:

1.  Griffiths, et al, 2006 Psychopharmacology (Berlin) http://www.ncbi.nlm.nih.gov/pubmed/16826400.

2.  Griffiths, 2009 TED talk: https://www.youtube.com/watch?v=LKm_mnbN9JY.

3.  Carhart-Harris, et al, 2012 PNAS (http://www.ncbi.nlm.nih.gov/pubmed/22308440)

4. Feb. 2015 New Yorker article: (http://www.newyorker.com/magazine/2015/02/09/trip-treatment

Wednesday
Dec092015

Manipulating Memory: From Inception to Neuroscience 

In Christopher Nolan's 2010 movie, Inception, Leonardo DiCaprio plants an idea or a specific memory in another person’s subconscious through a dream. Is this possible? Might be. MIT neuroscientists Liu and Ramire et al. have shown that they were able to create false memories in mice via optogenetics. Optogenetics is a technique that utilizes light stimuli to control specific genetically modified cells in living tissue via light-gated ion channel.

In their study, the mice were firstly subjected to a safe environment, Box A. Memories of this new environment were recorded in certain cells, which were programmed to respond to pulses of light. By applying light pulses, the mice will recall the memory of Box A. Then the mice were placed in a completely different environment, Box B, where the mice were subjected to foot shocks, with simultaneous delivery of light pulses into their brains to reactivate the memory of Box A. This resulted in a negative association between the light-reactivated memory of Box A and the foot shocks that the mice obtained in Box B. When the researchers put the mice back into Box A, it was observed that the mice displayed heightened fear responses. A false fear memory was implanted into the mice brain via artificial means.

This work has shown that memories can be altered during the recall process. The researchers pointed out that recall could make memories more labile and external information might be incorporated into existing memories occasionally over time. As Ramirez explained in their TEDx Boston talk, “The mind, with its seemingly mysterious properties, is actually made of physical stuff that we can tinker with.” Their work illustrates the increasing ability of neuroscientists to control, manipulate, and engineer memory in the brain.

 

Ref:

(1) Liu, X., Ramirez, S., Pang, P. T., Puryear, C. B., Govindarajan, A., Deisseroth, K., Tonegawa, S. Nature, 2012, 484 (7394), 381-385.

(2) Ramirez, S., Liu, X., Lin, P. A., Suh, J., Pignatelli, M., Redondo, R. L., Tonegawa, S. Science, 2013, 341(6144), 387-391.

(3) https://www.youtube.com/watch?v=kDXJhxLzmBQ

Monday
Dec072015

Your brain on music-what does the research tell us?

Music, one element of the performing arts, has been part of our lives for centuries. It is now easier than ever to access our music no matter where we are. We listen whilst we cook, drive, clean and even when going for a run. My daily routine includes habitually navigating YouTube in search of music to play before starting work. I wonder if this contributes towards my productivity throughout the day; or maybe it has become something of a distraction, a means to escape the pressure to perform at work by becoming an audience for the musicians and singers I select.

The relationship between music and fundamental function has been heavily explored. N. Perham and J. Vizard preformed a small scale trial (25 participants) to understand the effect of music on remembering items in a specific order. Tests were carried out to explore the difference in results whilst music was prevalent and also when it was absent. Participants achieved the highest scores in the absence of music and lower scores when background music was played, whether it was liked or disliked by the participants.

An investigation by W. Brodsky and Z. Slor also demonstrated that music can be disruptive to young newly qualified drivers when taking to the wheel. The driving of 85 young-novice drivers was tested while playing preferred music, in-car music and no music. Driving while playing preferred music was reported to boost positive mood and enjoyment; however, increased driver miscalculation deficiency and traffic violations were also observed. On the other hand, listening to music that generated moderate levels of perceptual complexity improved the drivers’ performance leading to increased driver safety.
 
  Both experiments required individuals to be highly attentive and focused. The results indicate that preferred music has some negative effect on an individual’s performance; Nevertheless, this does not mean that music is bad for you. Another study carried out by A. Cabanac et. al. showed that students (560 participant aged 14 – 17) that chose a music course in their curriculum obtain higher grades on average compared to students that did not choose music as an optional course. This is the case in all subjects including Sport, Math, English and Science. The authors conclude that music can help relieve stress and as a result students taking musical courses perform better.
 
Personally, I think that the effect of music differs from person to person and depends on the task at hand. I would ideally avoid listening to music when high concentration is required; however, I believe music could help when performing repetitive tasks, as it can lead to positivity and enjoyment and, thus, increased productivity.
~AKHD
N. Perham and J. Vizard (2010) “Can preference for background music mediate the irrelevant sound effect?” Appl Cogn Psychol. 25:625-631.
W. Brodsky and Z. Slor (2013) “Background music as a risk factor for distraction among young-novice drivers” Accid Anal Prev. 59:382-93.
A. Cabanac et. al. (2013) “Music and academic performance” Behav Brain Res. 256:257-60.