“Man had always assumed that he was more intelligent than dolphins because he had achieved so much — the wheel, New York, wars and so on — whilst all the dolphins had ever done was muck about in the water having a good time. But conversely, the dolphins had always believed that they were far more intelligent than man — for precisely the same reasons….In fact there was only one species on the planet more intelligent than dolphins, and they spent a lot of their time in behavioural research laboratories running round inside wheels and conducting frighteningly elegant and subtle experiments on man. The fact that once again man completely misinterpreted this relationship was entirely according to these creatures’ plans.” – Douglas Adams, The Hitchhiker’s Guide to the Galaxy

As tempting as it may be to believe the science fiction version of the intelligence rankings, real-life science has spoken and suggests (much to my displeasure) that humans may actually be the highest on the intelligence scale.

Glia are non-neuronal cells found in the brain mainly described as performing “housekeeping” functions, for example, providing structural support to neurons, and providing them with nutrients. Astrocytes are a specific type of glia, and as one might hypothesize, they are bigger in humans than in mice. Was this just a consequence of humans having more complex brains, or do these astrocytes have different functions in humans beyond the basic housekeeping functions? To test this, scientists grafted human astrocyte progenitor cells into developing mouse brains to create chimeric mice.

Human astrocyte (green) and mouse astrocyte (red)

The human astrocytes that matured successfully matured as human cells; characteristics such as their size were unaffected by being in a mouse environment. But they did not remain completely foreign – they successfully formed electrical connections with the mouse cells. Their differing cellular properties were thus propagated into the mouse neural networks. Of particular interest is the hippocampus, the brain region important for learning and memory. Chimeric hippocampal slices had a higher level of baseline excitatory activity, and long-term potentiation (LTP), or synapse strengthening, was much greater. At the molecular level, this can be explained because the human cells express higher levels of a protein that promotes an increased number of glutamate receptors at the synapse.

There were also clear differences in the behavior of chimeric mice. Experiments were performed to test learning and memory abilities to corroborate the cellular results observed in the hippocampus. A classic fear conditioning experiment involves pairing a tone with a foot shock; mice learn to associate the two and exhibit freezing behavior after hearing a tone. Chimeras learned the association after only one tone/shock pairing. The learning persisted for several days, during which time control animals did not learn the initial association. The experiment was repeated as context fear conditioning, meaning that the mice were placed in different chambers that had varying floors and odors. Chimeric mice were able to differentiate between chambers significantly better than their control counterparts. In other learning and memory tasks, these mice learned their way through mazes faster and were better at familiar object recognition in novel contexts.

The results of this study show that glial cells have much more function beyond their basic housekeeping properties. A single cell graft manipulation was enough to significantly improve mouse performance on learning and memory tasks. Complexity of these cells has evolved with the brain, and this provides important new insight on how exactly this complexity has come to be. Future experiments could involve grafting chimpanzee or macaque glia, any differences observed could be key in outlining how our processing abilities evolved from our monkey fathers (I additionally support research with dolphin glia grafts, keeping on the theme of the three most intelligent species). Unfortunately, without the higher processing abilities made possible by human cells, mice likely cannot achieve the tasks and level of status they exhibit in the science fiction. It seems as though man has indeed correctly interpreted his relationship with the mouse.

So long, and thanks for all the fish.

-Reena Clements

References:

Human Brain Cells Boost Mouse Memory – ScienceNOW

Forebrain Engraftment by Human Glial Progenitor Cells Enhances Synaptic Plasticity and Learning in Adult Mice – Cell Stem Cell

We have many different types of neurons within our peripheral somatosensory system. In addition to basic mechanoreceptors, we have neurons corresponding to pain sensations, and channels that are temperature sensitive. However, one phenomenon that was not explained at the neuronal level until recently, is the sensation of stroking. On the behavioral level, we know that stroking or grooming is pleasurable in such phenomenon as maternal care. But how is this transduced at the molecular level?

Researchers in David Anderson’s lab at Caltech recently discovered a class of neurons that selectively responds to “massage-like” stimulations. Experiments were performed in-vivo to directly measure the effect of certain stimulations. Calcium imaging, a type of imaging designed to study activity of neurons, was used in the spinal cord, where the cell bodies of neurons projecting to the periphery are located. After mice were pinched, poked, and light-touch stroked on their paws, the researchers found that a subset of neurons was selectively activated to only the light-touch stimulus.

Mouse being stroked (Discover Magazine and David Anderson Lab)

To help support the results behaviorally, mice were given a two-choice test between a chamber where they received a drug activating the light-touch neurons, or a chamber where they received a control saline solution. Mice preferred the chamber with the drug that activated the light-touch neurons, suggesting that the animals form a positive association with having these neurons activated.

While similar neurons are thought to exist in humans, more studies need to be done on the nature of the potential light-touch fibers. These studies, when paired with behavioral data, can also provide insight into the biological basis of stroking and grooming in behaviors such as maternal care or social bonding experiences. Perhaps the reasons for this innate behavior (who ever thought of hugs as a feel-good mechanism, anyway?) actually has a stronger molecular link than we initially thought.

And to tie in this study with internet culture, here’s a recap video:

Sources:

Genetic identification of C fibres that detect massage-like stroking of hairy skin in vivo – Nature

Behold – our recent ancestor, the gorilla, and ourselves, the human:

There are many characteristics that separate us from our monkey fathers. Most notably, factors that mark the evolution are the use of fire, use of tools, and a bigger brain. A recent study suggests that it is actually the onset of the use of fire that explains the ability to begin to grow a larger brain. According to a timeline of human history, the earliest Homo Sapiens appeared shortly after beginning to use fire to cook food:

What is it about cooking that allowed us to grow bigger brains? As the brain grows bigger, more energy is required to sustain the increased number of neurons. Gorillas could spend up to ten hours a day obtaining the food necessary to sustain both their brain and large body mass. Why is it that humans can spend significantly less than 10 hours per day to consume our required energy intake, but gorillas must be constantly eating? The tradeoff is in how we prepare our food. Gorillas live off of a raw food diet, whereas humans cook food. Cooking can be thought of as “pre-digesting.” Because we’ve already broken down much of the food by cooking, the calorie absorption process becomes more efficient than if the food had been raw, and requires that we put in a significant amount of energy to just digest. On just a raw-food diet of the gorilla, evolution could not have been possible, because the gorilla could never consume enough energy via raw food in a day to support a larger brain. The use of fire to prepare food paved the way for the evolution of organisms that could support significantly larger brains.

I’m no expert on nutrition, but as a general public service announcement after seeing this study, I would caution going on a raw food diet for a long period of time. Sure, as a vegetarian my canine teeth aren’t being put to use like they’re supposed to be. But I can still consume enough energy to be healthy by cooking my veggies. For those of you who want to try a raw food diet… well, I’m seeing some pretty solid evidence that the whole reason we’re here is because of cooking. And you can’t really argue with evolution.

For more information on the topic, see the transcript of a recent Live Chat hosted by Science.

Sources:

Raw Food Not Enough to Feed Big Brains – Science

Metabolic constraint imposes tradeoff between body size and number of brain neurons in human evolution – PNAS

Food for Thought – Science

Technology has largely improved the quality of life for patients needing implantable electronic devices, such as pacemakers or cochlear implants. Pacemakers allow for the heart to function properly and cochlear implants restore hearing to deaf patients. The downfall of these types of technologies is the way in which they are powered. Batteries are a common power source, and while they can be designed to have lifespans of several years, they do eventually need to be replaced. One could argue that this, to an extremely small degree, undermines the benefits of having the implantable device.

Researchers at MIT may have found a way to completely remove this inconvenience associated with having an implantable electronic device. What if we used the resources in our own body to power the electronic components we put into it after injury?

Glucose Fuel Cell Schematic

The researchers aimed to harness cerebrospinal fluid (CSF) to power a simple chip. They chose the CSF because it is mostly void of cells and proteins, free of the immune system, and has glucose levels comparable to other areas of the body (blood and tissues). This makes it an ideal niche to implant a device that uses the glucose present to generate power.

The fuel cell itself is composed of platinum roughened with aluminum to increase surface area available for oxidizing glucose. More specifically, glucose is oxidized at the anode of the fuel cell and oxygen is reduced to water at the cathode. The fuel cell is tested in artificial CSF and able to generate several hundred microwatts of power. It is also biologically compatible because it does not disrupt any natural processes of the CSF. The rate at which the cells use glucose and oxygen is much lower than their respective replenishment rates, so in theory, the fuel cell could produce electricity without causing chemical instability in its environment.

While stable in a biological environment, right now this fuel cell does not generate a lot of power. It’s not enough to power any sort of electronic implant currently available. It is also in the earliest stages of development as it has not been tested in real CSF or in vivo, animal models or humans. The researchers hope that as the technology is developed and improved, we will potentially be able to use the fuel cells to power devices such as prosthetic limbs in paralysis patients. For patients needing all types of electronic implant, the establishment of this technology could dramatically change the way they live their lives, dramatically improving quality of life for some, and change the field of biological electronics.

References:
Fuel Cells Run on Brain Power - Science

There are numerous brain imaging techniques that allow us to gain insight into what damage the brain may have incurred after a patient has a traumatic injury. The ever popular fMRI measures blood flow to infer neural activity. Diffusion tensor imaging (DTI) uses the magnetic properties of water to look at white matter in the brain, while positron emission tomography (PET) uses radiolabeling to look for a specific chemical in the brain. All of these are important for possible disease diagnosis, however, there is skepticism around how dependent we should be on this technology, as the results should never be taken as the absolute truth.

Comparison of X-Ray to HDFT

Now, a new type of brain imaging developed by researchers at the University of Pittsburgh allows researchers to look for connections that have been broken as a result of traumatic brain injury, much like an X-Ray allows doctors to look for broken bones. It is called High Definition Fiber Tracking (HDFT). Although the technology is not specific at the cellular level, it is accurate in observing specific connections that have been lost as a result of injury. These lost connections act as a reliable predictor for  cellular information, such as the percentage of axons that have been lost.

The accompanying publication in the Journal of Neurosurgery focuses on a case study of a man who sustained severe brain damage after crashing an all-terrain vehicle (public service announcement: this is why we wear helments!!!). Initial MRI scans showed hemorrhaging in the right basal ganglia, which was confirmed by a later DTI. The patient  had extreme difficulty moving the left side of his body, and it was assumed to be a result of damage to the basal ganglia. It was not until the patient had a HDFT test that doctors could pinpoint the true problem: fiber tracts innervating the motor cortex had been lost.

Above is a comparison of the techniques that the researchers saw. The first column consists of scans from a normal patient, while the second two columns are the brain injury patient 4 and 10 months post injury. The imaging techniques used are MRI, DTI, and HDFT. The HDFT gives a clearer picture of what specific connections in the brain have been lost.

The following image comparing DTI with HDFT also shows the inaccuracies of the older technologies.

In healthy subjects, the DTI shows connections and fiber tracks which do not correspond with what we know about brain anatomy, including false turns (deviations from the pathway), false continuations (midline crossing), and looping (travel in random directions). The HDFT scan is consistent with brain anatomy. Thus, the use of HDFT was essential in pinpointing exactly what connections had been lost as a result of the patient’s traumatic brain injury (see Figs 5 and 6 in accompanying paper, linked below).

HDFT has the potential to become the future of diagnoses in patients who have sustained traumatic brain injury, thus revolutionizing how we can treat these patients.

The following video shows a summary of the new technology in addition to the patient in the research paper’s case study:

New Brain Imaging Technique Reveals Damage Caused by TBI … -YouTube

Further videos and news releases are available on the HDFT lab website, linked below.

References:

Concept | HDFT – High Definition Fiber Tracking – HDFT

High-definition fiber tracking for assessment of neurological deficit in a case of traumatic brain injury: finding, visualizing, and interpreting small sites of damage. – Journal of Neurosurgery

New High Definition Fiber Tracking Reveals Damage Caused by Traumatic Brain Injury -University of Pittsburgh Medical Center

The parting words of Ken Jennings in last year’s Jeopardy match against Watson, a computer seemingly able to decipher and process language, are a milestone for robotic innovations. Advancements in neuroscience and robotics have focused on giving robots human-like intelligence and processing skills. This concept has been depicted numerous times in popular culture, many times in terms of robotic rebellion, for example in movies such as I, Robot or WALL-E.

Recent robotics research leaves us with a couple of questions. Are really focusing on the right aspects of advancing in robotic technologies? Instead of perfecting intelligence and processing, why not instead focus on perfecting human emotion?

Facial cues have proven extremely important for social interaction. In experiments where robots greeted humans and asked them to perform a task, the humans were more receptive when the robot glanced at the task to be performed, rather than robotically (pun intended) looking at the human subject while giving instructions. A similar experiment was set up in which human subjects were to learn about China. A map of China was present in the classroom. Those who had robot teachers who looked at the map while teaching actually learned more about the spatial relationships pertaining to the “lecture material” than those who had robot teachers who never looked at the map.

Another study examined the responsiveness of infants to robot facial cues.

Child following robot gaze

An 18-month old infant was allowed to watch a robot interact with a human (the researcher). He would point tobody parts, and the robot would repeat the action. When the researcher left the room, the infant followed the robot’s gaze. In contrast, those infants who never saw the robot interact with a human were unresponsive to their gazes. Visual communications are key for learning social interactions.

Such robots have also been used in Autism Spectrum Disorder (ASD) therapies. ASD patients have trouble with social interactions, so these social robots have been hypothesized to help in therapy. A bubble test, in which a companion to the patient blows bubbles, is used as it has been shown to provoke social interaction. ASD subjects were either allowed to interact with the robot to receive bubbles (such as by pushing a button) as well as a motor output from the robot (spinning) or could sit and watch while the robot did nothing. Those patients who were allowed to interact with the robot showed a significant increase in social behaviors such as speech and continued robot interaction. Thus, it has been concluded that the robots’ social behaviors are causing a response in ASD patients.

This work shows that robots are gaining prevalence in studying the social aspects of human intelligence. While it is still important to use robotics to study how human processing works, it will be of extreme value to also continue research in the field of emotions and social communication.

Developing Robots That Can Teach Humans – Science Nation

“Social” robots are psychological agents for infants:: A test of gaze following – Neural Networks

Toward Socially Assistive Robotics for Augmenting Interventions for Children with Autism Spectrum Disorder – Experimental Robotics

When humans fall ill, we can go to the doctor to receive a diagnosis and treatment. We have a form of communication, and our body has good indicators that can help the doctor diagnose the problem. But what happens when we are trying to diagnose organisms that have no way to tell us what is wrong, and no way of knowing how badly they are affected? For instance, in the case of many marine organisms, illness is being caused by humans. We have used our oceans such that they now contain areas with little to no oxygen, where life is barely sustainable. How does this, combined with ongoing pollution and human activities, stress marine life?

Researchers at the College of Charleston recently faced this problem, and have developed a method of “talking” to crustaceans such as shrimp and blue crabs through motor physiology. Karen and Louis Burnett have created an underwater treadmill to determine vital signs as a measure of stress. The study organisms are infected with bacteria, and water conditions on the treadmill can be regulated to encompass various oxygen levels, pH, and other water quality characteristics. Vital signs such as heart rate and blood pressure from the infected animals can then be compared to those of uninfected animals in the same water conditions (the same vital signs that are used in human stress tests). The studies are also looking at muscle physiology to examine the use of aerobic and anaerobic respiration to molecularly determine how stressed animals are affected. How are abilities necessary for their lives, such as walking and swimming, affected by bacterial infections and water oxygen levels? The Burnetts have found that uninfected animals perform better on the treadmill, and that infected animals have a hard time taking up oxygen due to immune responses. Additionally, the animals’ ability to fight infection is negatively affected by a low oxygen supply in the water. Continual study to answer questions such as these will help assess what we can change in our use of natural resources.

See an interview with the Burnetts here.

And just for fun…here’s shrimp on a treadmill!

Reference:
Energy metabolism and metabolic depression during exercise in Callinectes sapidus,
the Atlantic blue crab: effects of the bacterial pathogen Vibrio campbellii – The Journal of Experimental Biology

City dwellers are all too familiar with crowds. In Boston, students regularly navigate through them on their way to class, and more broadly, natives and visitors all have to navigate through sports crowds. These can be particularly dense and sometimes rowdy crowds (have you ever been near Fenway Park after a Red Sox-Yankees game?!).

With crowds occasionally come large-scale riots. A recent notable riot occurred in Vancouver after the Bruins won the Stanley Cup over the Canucks. One of the first signs of unrest was bottles being thrown at TV screens by spectators outside the stadium. It was followed with burning of Bruins apparel and flags. Eventually, a car and truck were overturned and set on fire, and windows of local businesses were smashed. Chaos followed, 100 people were arrested, and there were numerous injuries.

Researchers at Arizona State University are currently studying human behavior in crowds. They use computer modeling to study the outbreak and containment of city riots. One such example can be found here. This video shows the beginnings of a riot outbreak through an immersive model – the progression of the riot and overall crowd behavior is observed from a participant’s point of view. Though various viewpoints are shown in the video, there is initially a focal point of a key initiator, and users can choose their viewpoint when modeling in the program.

This type of modeling can also produce various types of “predictor” maps to give further information on the behavior of the crowd and the action authorities should take in order to prevent the crowd from spiraling out of control. The first of such is a play on a topographic map.

This map gives information about the position and “influence circles” of various members of the crowd – police (gray), rioters (red), nonrioters (blue), and vulnerable onlookers (Torrens).

The research takes this map one step further by adding a time component.

Timescale map of riot control

This map shows, over time, the movement of police, those who are arrested, those who continue to riot, and the bystanders. The gray plane represents the riot scene, while time is represented by lines and curves rising above the plane.

Research on riots provides valuable insight into the origin and sustainability of riots, as well as predictions as to how best focus police efforts to settle rowdy crowds. Coupled with research simply concerned with crowd behavior, we can better plan the arrangement of city areas expecting large crowds.

Video Timeline of Vancouver Riot Development – Canadian Television Network

Subtle Movements in Crowds Lead to Large Scale Phenomena – research.gov

Simulation of Mob Mentality – Geosimulation

Dolphins are pretty amazing creatures, to put it simply. In Douglas Adams’ The Hitchhiker’s Guide to the Galaxy, the dolphins knew of the Earth’s impending doom well before people did (“So long, and thanks for all the fish!”). In addition to their extraordinary cognitive abilities, they have highly developed and extremely interesting social skills (such as killing for pleasure).

Speaking of killing, let’s discuss sharks. Contrary to popular belief, sharks are only dangerous if you give them reason to be. During the course of my summer internship, I’ve seen many sharks, from toothless dogfish to five foot long juvenile tiger sharks. All have been docile; they tend not to try to attack unless you poke them hard enough (in an out of water case). But, say you happened to be standing in front of the aforementioned tiger shark’s mouth and poked it, and it flailed and bit your leg. You’d probably scream in pain, bleed, and need to see a doctor right away.

Now consider an in water encounter between a dolphin and a shark. The dolphin could just be swimming normally and pass a shark. The shark could misinterpret the dolphin swimming nearby as a threat, and attack, leaving a 3 centimeter deep, 30 centimeter long, 10 centimeter wide wound. Not only would the dolphin not feel pain from this, but it would continue feeding, swimming, and behaving normally! Even more amazingly, the wound would heal over time with little scarring or changes in overall contour!

Wound healing over time in a bottlenose dolphin

Wound healing over time in a bottlenose dolphin

A recent study by Zasloff investigated the remarkable healing process in bottlenose dolphins. Though little is known about the pain reflexes in dolphins, it has been shown that they will withdraw when pricked. In response to long lasting wounds caused by shark attacks, dolphins have been observed to exhibit normal swimming and feeding behaviors in as little as two days after the attack. They do not seem protective of their wounds in the slightest either. What is it about the dolphin’s pain circuits allows them to seemingly ignore serious wounds?

The biological and biochemical healing process is likely due to special adaptations resulting from a marine lifestyle. Dolphin wounds may be less likely to bleed due to a diving reflex adaptation. When diving, dolphins divert their blood supply to their inner vital organs, allowing them to spend longer periods of time underwater. This reflex might also come into effect after sustaining a traumatic wound. However, what makes the process truly remarkable is that it mimics the process of regeneration. Just like a starfish can regrow an arm, this process allows deep wounds to heal almost flawlessly in dolphins. Blubber invades the wound and repairs the tissue with the already existing blubber structure. In addition, blubber contains both natural organohalogens and short chain fatty acids known as isovaleric acids, both of which serve as antibacterial agents. Given the amount of bacteria in the marine environment, these must be extremely effective against preventing infection in the wound.

Not meaning to wish harm on dolphins, but studying their wound healing process could give tremendous insight into how humans can successfully manage injuries. We could potentially produce numerous new painkillers or antibiotics if we found the right chemicals in dolphins. Studying the regeneration-like healing may lead to new discoveries in stem cell research. Though we probably still will not be able to regrow limbs, the field has immense potential in treating localized but serious wound injuries.

Observations on the Remarkable (and Mysterious) Wound-Healing Process of the Bottlenose Dolphin : Letter to the Editor, Journal of Investigative Dermatology

For patients who have lost their sight to various eye diseases, artificial retina technology allows them to experience limited vision once more.

The external parts of the artificial retina device include glasses with a mounted camera and a small computer.

The device also includes an electrode implanted onto the patient’s retina. When the camera “sees” an image, the computer is able to translate these into a pattern of neural signals. This pattern is then transmitted to the implanted electrode, and directly stimulates the optic nerve. These signals are then able to be processed by the brain and interpreted as very rudimentary images.

The first artificial retina to be implanted in a patient, known as Argus I, included only sixteen electrodes that stimulated the optic nerve. However, the patient with this implant was still able to tell the differences between light and dark, and could make out basic shapes. The newer version of the technology, Argus II, now includes sixty electrodes. However, it is still limited in that patients can only tell the differences between light and dark areas, and can only see shapes, outlines, and blurs, and not detailed images. Regardless, this is a large improvement over no sight, and patients with the implant are satisfied with simply a partial regain of their vision, and are hopeful that the technology will continue to improve. As of late, a third model of the artificial retina is in development, and will include over 200 electrodes.

Though the project began almost ten years ago, the implant has recently been approved for patients in Europe. The company has not yet submitted approval to the FDA, but hopes to do so by the end of this year.

Second Sight – How is Argus II Designed to Produce Sight?

CBS News HealthPop – First Artificial Retina Approved in Europe

US Department of Energy Office of Science – About the Artificial Retina Project