Counting Crows: Evidence for Hard-Wired, Inborn Ability to Detect Numerical Sets

“The Great Book of Nature is written in mathematical language” –Galileo Galilei (1)

carrion crow (corvus corone) headshot portrait against a blue background

Carrion Crow (Corvus corone)

If mathematics is the language of the universe, might we find the ability to do math hard-wired in species?

Research in primates has demonstrated that even without training, humans and monkeys possess numerosity, the ability to assess the number of items in a set (2,3).

A paper in Current Biology from Wagener and colleagues provides evidence that crows are born with a subset of neurons that are “hard wired” to perceive the number of items in a set (4). This work provides yet more evidence supporting a hypothesis of an innate “number sense” that is provided by a specific group of “preprogrammed” neurons.

In this study, Wagener’s group measured the responses of single neurons in two “numerically naïve” crows to color dot arrays. They measured neurons in the endbrain region known as the niopallium caudolaterale (NCL), which is thought to be the avian analog of the primate prefrontal cortex. They found that 12% of the neurons in NCL specifically responded to numbers and that specific neurons responded to specific numbers of items with greater or lesser activity.

This is the first such study to investigate the idea of an innate “sense of number” in untrained vertebrates that are not primates, and as such it suggests that a hard-wired, innate “sense of number” is not a special feature of the complex cerebral cortex of the primate brain but is an adaptive property that evolved independently in the differently structured and evolved end brains of birds.

Many questions remain. Are there similarities in the actual neurons involved? What does learning do on a physiological level to these neurons: Increase their number, increase connections to them?  What other vertebrates have similar innate mechanisms for assessing numbers of items? What about other members of the animal kingdom that need to have a sense of number for social or foraging behavior? How is it accomplished?

And finally, one last burning question, if birds are dinosaurs, does that mean that dinosaurs perished because they didn’t do their math homework? Asking for an eleven-year-old I know.

  1. Tyson, Peter. (2001) Describing Nature with math. NOVA 
  2. Izard, V. et al. (2009) Newborn infants perceive abstract numbers PNAS USA 106, 10382–85.
  3. Viswanahtan, P. and Neider, A. (2013) Neuronal correlates of a visual “sense of number” in primate parietal and prefrontal cortices. PNAS USA 110, 1118–95.
  4. Wagnener, L. et al. (2018) Neurons in the endbrain of numerically naïve crows spontaneously encode visual numerosity Cur. Biol. 28, 1–5.

A Surprising New Role for Body Fat?

This cloaked fat cell just might be a superhero.

Forty-some years ago fat was just fat. And it was regarded with disdain, to say the least.

An entire industry existed to help get rid of fat, using what was then the latest mass media technology, television. If you wanted to get rid of fat you could exercise with Jack LaLanne as he worked out on television. We exercised in elementary school PE class to a vinyl recording of “Chicken Fat”. You could strap into a device that employed shaking to get rid of the fat from your “hips”, or eat a piece of chocolate fudge with a hot beverage before meals to curb your appetite.

Fat was not our friend. We knew long before the current diabetes epidemic that being overweight was not good for our health.

Fast forward to the 21st century, where we’ve learned that some forms of fat are actually good for you–important in metabolism, growth and immunity. The variety of types of mammalian fat include brown adipose tissue, beige adipose tissue and white adipose tissue, and it’s possible to convert one to the other under certain conditions. For details on these types of adipose tissue, read this article —after you finish this blog. Continue reading

Characterizing Multi-Subunit Protein Complexes Using Cell-Free Expression

artist's concept of a cell membraneMulti-subunit protein complexes control membrane fusion events in eukaryotic cells (1). CORVET and HOPS are two such multi-subunit complexes, both containing the Sec1/Munc18 protein subunit VPS33A (2). Metazoans additionally possess VPS33B, which has considerable sequence similarity to VPS33A but does not integrate into CORVET or HOPS complexes and instead stably interacts with VIPAR. Recent research suggests that VPS33B and VIPAR comprise two subunits of a novel multi-subunit complex analogous in configuration to CORVET and HOPS (3).

In a recent publication (4), Hunter and colleagues, further characterized the VPS33B and VIPAR complex. Using co-immunoprecipitation and proximity-based ligation assay, they identified two novel VPS33B-interacting proteins, VPS53 and CCDC22.

In vitro binding experiments, VPS33B and GST-VIPAR were co-expressed in Escherichia coli and purified by GSH affinity. The VPS33B/GSTVIPAR complex was used as bait in pulldown experiments, with myc-CCDC22 and myc-VPS53 expressed by cell-free in vitro transcription/translation in wheat germ lysate. Myc-CCDC22 was very efficiently pulled down by VPS33B/GST-VIPAR, whereas myc-VPS53 was not .The interaction between VPS53 and the VPS33B-VIPAR complex was either indirect, requires other proteins contribute to the interaction, or requires a post-translational modification not conferred in the plant cell-free expression system (wheat germ). Pull-down experiments with individual subunits or expressing as complexes, was inefficient and did not result in binding to VPS33B/GST-VIPAR.

To further understand how VPS33B-VIPAR may interact with CCDC22, Hunter and colleagues attempted to refine the region of CCDC22 that interacts with VPS33B/GST-VIPAR by generating a series of truncated forms of CCDC22. However, none of five CCDC22 truncations were able to bind to VPS33B/GST-VIPAR. The hypothesis was that truncated forms of CCDC22 are unstable and unable to fold correctly in this assay system.

Additional experiments noted that the protein complex in HEK293T cells which contained VPS33B and VIPAR was considerably smaller than CORVET/HOPS, suggesting that, unlike VPS33A, VPS33B does not assemble into a large stable multi-subunit protein complex.


  1. D’Agostino, M. et. al. (2017) A tethering complex drives the terminal stage of SNARE-dependent membrane fusion. Nature 551, 634–638.
  2. Balderhaar, H. J. K. and Ungermann, C. (2013) CORVET and HOPS tethering complexes – coordinators of endosome and lysosome fusion. J. Cell Sci. 126, 1307–16.
  3. Spang, A. (2016) Membrane Tethering Complexes in the Endosomal System. Front. Cell Dev. Biol. 4, 35.
  4. Hunter, M.  et. al.  (2017) Proteomic and biochemical comparison of the cellular interaction partners of human VPS33A and VPS33B. [Internet bioRxiv  Accessed 3/12/2018]

Science News: Demoting Termites, Monitoring Blood Pressure with Your Smartphone and Finding Amelia Earhart’s Bones

A few science news items caught my eye this week.

Macro image of a termite (Isoptera) found under a rock. Image by Sanjay Acharay via Wikimedia Commons.

Wood-Shattering Revelation: Termites have been recategorized based on genetic and other evidence. Turns out, they are just social cockroaches and thus, have become part of the cockroach order Blattodea rather than remaining in a separate order. This decision was not made lightly, but based on years of debate amongst American entomologists. The insects will still retain termite in their name, but they gain a reputation for surviving apocalyptic events. Read about the update to the insect name master list by the Entomological Society of America.

Sphygmomanometer with cuff, used to measure blood pressure via Wikimedia Commons.

Blood Pressure Measurements at the Tip of Your Finger: A blood pressure cuff is bulky, annoying but accurate for monitoring the effort needed for pushing blood around your body. While this device is a fairly simple one, in the developing world it is not that common. However, mobile phones are available to many more globally so why not find a way to put the two together? Turns out that smartphones are equipped with hardware that can be used to measure blood pressure. By adding a device that attaches to the back of a smartphone and with the press of a finger, you can monitor your blood pressure. While not currently as accurate as a blood pressure cuff, the people that tried the mobile blood pressure device were able to quickly adapt to using it, making it easy to take several readings for continuous monitoring. A pocket-sized blood pressure monitor without the nasty squeeze of your arm sounds like a great medical advancement for treating high blood pressure. See a video of the device.

Photo of Amelia Earhart and Dr. Edward C. Elliott, president of Purdue University with the Lockheed Electra she later disappeared in. Purdue University paid for the plane as Earhart was then a consultant on aeronautics there. Photo taken 20 August 1936.

For a Forensic ID, All You Needed Was a Picture, Old Clothing and Some Numbers: The quest to find where Amelia Earhart may have landed in the Pacific Ocean has been investigated and speculated about since she and her navigator disappeared July 2, 1937. In fact, skeletal remains had been found on a remote island in the South Pacific in 1940 along with other artifacts–a woman’s shoe, an American sextant box, but the bones were identified as a man by a physician at the time. Unfortunately, these remains have subsequently been lost. Recently, an anthropologist decided to take the measurements made in 1940, and using a modern-day techniques including a program that estimates stature, sex and ancestry, and he found that the bone measurements were more consistent with Earhart than with 99% of the reference sample used. In addition, using a photograph of the American pilot that had scale generated bone lengths of her humerus and radius and measuring her clothing from a collection gave a number for her tibia. All these numbers strongly suggest the skeletal remains were Earhart’s. Read the press release.

A Better Way to Understand How and Why Cells Die

Real-time, up-to-the-minute access to information provides new opportunities for scientists to monitor cellular events in ever more meaningful ways. Real-time cytotoxicity and cell viability assay reagents now allow constant monitoring of cell health status without the need to lyse or remove aliquots from plates for measurement. With a real-time approach, data can be collected from cell cultures or microtissues at multiple time points after addition of a drug compound or other event, and the response to treatment continually observed.

The CellTox™ Green assay is a real-time assay that monitors cytotoxicity using a fluorescent DNA binding dye, which binds DNA released from cells upon loss of membrane integrity. The dye cannot enter intact, live cells and so fluorescence only occurs upon cell death, correlating with cytotoxicity. Here’s a quick overview showing how the assay works:

More Data Using Fewer Samples and Reagents
The ability to continually monitor cytotoxicity in this way makes it easy to conduct more than one type of analysis on a single sample. Assays can be combined to determine not only the timing of cytotoxicity, but to also understand related events happening in the same cell population. As long as the readouts can be distinguished from one another multiple assays can be performed in the same well, providing more informative data while using less cells, plates and reagents.

Combining assays in this way can reveal critical information regarding mechanism of cell death. For example, assay combinations can be used to determine whether cells are dying from apoptosis or necrosis, or to distinguish nonproliferation from cell death. Combining CellTox Green with an endpoint luminescent caspase assay or a real-time apoptosis assay allows you to determine whether observed cytotoxic effects are due to apoptosis. Cytotoxic and anti-proliferative effects can be distinguished by combining the cytotoxicity assay with a luminescent or fluorescent cell viability assay. Continue reading

The Free Scientific Resource: Evaluating the Accuracy of Wikipedia

Several weeks ago, I came across an article on about how Wikipedia is becoming a scientific resource, whether we like it or not. Scientists are reading Wikipedia, the article said, and it’s affecting how they write. The article cited a study by researchers from MIT and Pitt that found statistical evidence of language in peer-reviewed articles being influenced by Wikipedia articles relevant to the topic. They concluded that journal articles referenced in Wikipedia are subsequently cited more than other similar articles, and that on a semantic level, Wikipedia is influencing the language of scientific journal articles at an astounding rate.

I was intrigued by the idea that reading Wikipedia affects how we later write about a subject. When I start writing about a new topic, the first thing I do is head to Wikipedia to gather a basic understanding before I dive into journal articles. I’ll skim through the overview and most relevant subsections, then check out the references to see what I should continue reading. However, the findings of the study imply that even though I don’t directly use information or language from Wikipedia in my work, it’s still subtly influencing how I write. Continue reading

Announcing: 17th International Forum on Consciousness

Means and Metrics for Detecting and Measuring Consciousness

Speakers on stage during last year's conference.

Panel speakers from last year’s Forum on Consciousness.

A diverse panel of thought leaders in neuroscience and consciousness, from the chief scientist and president of the Allen Institute for Brain Science to the principal English translator for His Holiness the Dalai Lama, will explore Means and Metrics for Detecting and Measuring Consciousness at the 17th International Forum on Consciousness May 17–18, 2018, in Madison, Wisconsin.  Presenters will discuss emerging technologies for looking into the phenomenon of consciousness such as sleep, wakefulness, altered states, focused attention, and coma. The Forum will ask how the ability to better measure consciousness may create opportunities to improve human function, resolve disease states, and keep the brain/mind healthier throughout all stages of life.

WHAT: The International Forum on Consciousness is a yearly event dedicated to information-sharing and discussion regarding important—and often challenging—topics related to the exploration of consciousness. It is co-hosted by the BioPharmaceutical Technology Center Institute (BTC Institute) and Promega Corporation.

WHEN: May 17-18, 2018

WHERE: BioPharmaceutical Technology Center, Promega Corporation, 5445 East Cheryl Parkway, Fitchburg, WI 53711

REGISTRATION: The International Forum on Consciousness is open to the general public but limited to 300 participants. Registration is $265 and there are a limited number of scholarships available to assist with the cost. Forum registrants also have the opportunity to join a presenter for a small group discussion over dinner on Thursday evening, May 17 for an additional $90. For more information or to register, visit


Which DNA Do I Use? How to Choose Your Control and Other DNA Samples


DNA double helix molecules and chromosomes.

Today’s Promega Connections blog is written by guest blogger Joliene Lindholm, Promega Technical Services Scientist.

In Promega Technical Services, we are frequently asked questions about choosing among our Human Genomic DNA products. Promega offers DNA that can serve as sources of normal human gene sequences or positive controls where genotype is not critical, and controls for use in genotyping applications like STR analysis. For mouse researchers, we also offer Mouse Genomic DNA. Continue reading

A Cell Viability Assay for Today

Valued for ease of use and scalability, plate-based, bioluminescent cell viability assays are widely used to support research in biologics, oncology and drug discovery.

Cell viability assays are a bread-and-butter method for many researchers using cultured cells —everyday lab tools that are a part of many newsworthy papers, but rarely make news themselves.

Over time, cell viability assays have become easier to use and more “plug ‘n play”. Among modern assays, luminescent plate-reader based systems have been a favorite for several years because of their superior sensitivity, robustness, simple protocols and uncomplicated equipment requirements (all you need is a plate-reading luminometer). These qualities combine to allow easy scalability and adaptability from bench research to high throughput applications.

CellTiter-Glo® Luminescent Cell Viability Assay is an accepted go-to viability assay for many researchers. The assay measures ATP as an indicator of metabolically active cells. A quick search on Google Scholar returns 3,990 CellTiter-Glo results for 2017 and over 500 so far in January and February of 2018. A sampling of these recent publications gives a snapshot of some of the ways the CellTiter-Glo assay is used to support key areas of research today.

Does a treatment kill cells?

The obvious application of a cell viability assay is to understand whether cells are alive. In cancer research, the CellTiter-Glo assay is often used to confirm killing of tumor cells and to verify that normal cells survive. Therefore, these assays are a key part of the evaluation and screening of drug candidates and other therapies for cancer. Many papers reporting use of CellTiter-Glo are developing and evaluating the effectiveness of novel anti-cancer treatments. Continue reading

National Optimism Month—Make it a Year

People working togetherToday’s Promega Connections blog is written by guest blogger Tori Sheldon, North America Marketing and Events Coordinator.

It is crazy to think how quickly the months fly by. It feels like yesterday I was watching the ball drop as 2017 turned to 2018. Now it is almost March, when Wisconsin starts to emerge from the cold winter. March also happens to be National Optimism Month.

As I think about optimism, I am reminded of one of the core values that guide interpersonal relationships at Promega: “look for the good, with discernment”.  The spirit of this value is to remember that deep down everyone is trying to come from a positive place and that even though we may not always agree with each other it is an opportunity for further discussion and collaboration.

This value is a part of the Emotional & Social Intelligence (ESI) program at Promega. Continue reading