Monday
Dec092013

Seeing is believing

Visualization of data is paramount to understanding and communicating science. This is particularly salient for experimental results that are presented as pictures, which in our lab can include anything from patterns of antibody staining in a dish of cells to heat maps of gene expression signatures to statistical parametric maps from in vivo human imaging. Many factors can change the visual appearance of such data sets. For example, adjustments to the contrast of an image or the thresholding of a color scale can make an effect jump out from the background signal without any changes to the underlying numerical data. There's good reason to display big datasets as pictures. The human brain is incredibly fast at processing complex visual information, and a well-made figure in a manuscript or group meeting presentation can convey a key point within seconds. The trade-off for that speed is yet another level of image processing, one that is inherent to the neurobiology of vision. Simply put, our perception of hue and saturation is highly context-dependent. This bias is nearly undetectable until revealed by optical illusions. Below are some great examples of relative perception from Japanese psychologist Akiyoshi Kitaoka (best known for his rotating snakes illusion). His website may be viewed here

The center square is the same color.

White's effect. The spades are the same shade of gray.

 Koffka ring. The bottom figure contains only 3 shades of gray.

The shade of red is the same in all boxes.

 

These visual illusions persist even after we are made aware of them! So next time you look at color gradients on a heat map, remember that perception is relative and no substitute for quantification.

-Emily

Tuesday
Dec032013

NY Times article: “Addiction Treatment With a Dark Side”

On Nov 17th 2013, an article was published in the New York Times by Deborah Sontag titled “Addiction Treatment With a Dark Side”. This in-depth article sheds light on the mu opioid agonist buprenorphine, most commonly sold under the name Suboxone. The article describes both the positive impact buprenorphine has had battling opioid addiction and also, the potential abuse; typical side effects of mu opioid receptor agonists. Suboxone is formulated combining buprenorphine (long acting, mu opioid receptor partial agonist) and naloxone (mu opioid receptor antagonist) to lower abuse potential. Unfortunately, recreational drug users have been abusing suboxone for years even though the “high” felt is minimal in comparison to other commonly abused mu opioid agonists. Suboxone generated $1.55 billion in U.S. sales last year (surpassing Viagra and Adderall). The inconvenience of methodone clinics and the limited choices for doctors trying to treat opioid addiction, suboxone prescriptions and sales have exploded over the last 10 years. Unfortunately some doctors have carelessly over prescribed suboxone in an effort to generate revenue for their clinics, which has increased abuse of the drug. This article breaks down the arguments from skeptics and believers of the blockbuster drug suboxone and other buprenorphine formulations, providing a sound debate on the controversial drug. This article was followed up a day later as a two part series. The second article was titled “At Clinics, Troubled Lives and Turbulent Care”. Part 1 is worth a read and if you are intrigued, part 2 sheds light on the clinics prescribing these pain medications. Enjoy!

-Mike Placzek

Monday
Nov182013

Santacruzamate A

Here in the Hooker Lab we have developed an HDAC inhibitor we call Martinostat that we are using as an imaging probe for PET. We were excited to see a new HDAC inhibitor in the literature termed santacruzamate.

So what is santacruzamate A? 

 The Panama-based International Cooperative Biodiversity Group (ICBG) has focused on natural product drug discovery from Panamanian plants and microorganisms with a particular emphasis on the discovery of antiparasitic and anticancer lead molecules. Work with marine cyanobacteria has been especially productive and a number of anticancer and antiparasitic agents have been isolated from these organisms. In a recent paper, the authors report on the isolation of a selective HDAC inhibitor with extraordinary potency against HDAC2, a class I HDAC enzyme. Due to the collection of the source organism from near Santa Cruz Island in Panama’s Coiba National Park, a UNESCO World Heritage Site, this carbamate derivative has been named santacruzamate A.

For more information, please chect out the paper here:

http://pubs.acs.org/doi/abs/10.1021/np400198r

http://www.flickr.com//photos/uconntoday/sets/72157632246777616/show/

Changning

Thursday
Nov142013

Pain tolerance and yoga

I recently found a research study focusing on pain tolerance and yoga that I found quite interesting. The study measured tolerance to cold and heat pain in control and yoga-practicing subjects and saw yoga practitioners were able to sustain pain twice as long as controls. Using MR imaging they also reported increased insular cortex volume in the yogis’ brains, which was positively correlated to the number of years the subject had practiced yoga.

The discussion addresses some thought-provoking concepts regarding possible mechanisms underlying the effects they observed and the perception of pain in general. They pointed out the possible confounds involving the placebo effect in pain research, as the expectation of pain lessening is actually quite effective in easing the pain. They also discussed with the subjects their mental strategies to deal with the pain and suggest that strategies used by yogis that “increase their parasympathetic activation and interoceptive awareness” may have strengthened (and enlarged!) the brain’s pain processing center. Some of these strategies such as focusing on the sensation and accepting the painful sensation may seem counter intuitive, as they were the exact opposite method of the control subjects, who mainly chose to ignore the pain or distract themselves.

Although I am still learning a lot about the pain modulating system in the brain, this study highlights the distinction that pain is a subjective experience. Are the yoga practitioners actually feeling less pain, or they are feeling it and accepting it? It would be fascinating to run a study like this using PET imaging or fMRI to see real-time brain dynamics in yoga practitioners with enlarged insula.  ~Misha

Check out the article here:

http://www.ncbi.nlm.nih.gov/pubmed/23696275

Tuesday
Oct292013

Seriously? ... people are trying this at home.

http://www.nytimes.com/2013/10/29/science/jump-starter-kits-for-the-mind.html?_r=0

In our lab, we are increasingly interested in techniques like transcranial magenetic stimulation (TMS) but I don't think we've ever considered just using a 9-V battery to stimulate the brain.  I have to advise against self-manipulation of your brain with electricity at home.  It is amazing to me what people will do.