“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

Scientists from Duke University and Brazil claim wires connecting one rodent to another can allow communication spanning continents via the internet. Professor Miguel Nicolelis of Duke University in Durham, North Carolina, led a team of researchers who demonstrated that it is possible to transmit instructions from one animal to another by brain-to-brain communication, a process akin to telepathy.

Brain-to-brain communication could be the start of  organic-based computing based on networks of interconnected brains. Pairs of laboratory rats were able to communicate with each other using microscopic electrodes implanted into their brains. This occurred as part of an experiment where the two rats had to work together in order to receive a reward (see video at source).

The researchers had this to say: “as far as we can tell, these findings demonstrate for the first time that a direct channel for behavioral information exchange can be established between two animal’s brains without the use of the animal’s regular forms of communication.” One rat in each pair, assigned to be the encoder, detected the signals of where to find a food reward and had to communicate these instructions to a second decoder rat. Once the second rat followed the first rat’s instructions, both rats would receive a reward. These communications were able to be sent over the internet, with rats at one lab in Brazil communicating with rats at the other lab in North Carolina.

Professor Nicolelis inserted micro-electrode implants into the rats’ brains to record the neuron activity associated with decision-making. Putting these signals through a computer encoder transmitted them to the second rat via wires connected to another set of micro-electrode implants. The second rat learned how to decode the signals quickly for its own use.  Each rat was trained to find water in its cage based on the type of signals they were given. However, only the encoder rat was actually exposed to the signals, which it had to pass on  correctly to the decoder rat. The decoder rats managed to find the reward in about 70% of trials.

What is most interesting, however, was the scientists found that when two rats were paired up they quickly established a rapport based on  some sort of sensory feedback. If the second rat failed at its task, the first rat would modify what it was transmitting to help the second rat. Both rats worked together since they were sufficiently motivated by the reward.

Future work could encode entire thoughts, hopefully connecting more brains to each other, boosted by the effect of sensory feedback rapport.  Professor Christopher James of the University of Warwick, who conducts similar research, said that the technique is still very crude since it relies only on monitoring one part of the rat’s brain for its nerve activity. “Leap into the future by, say, 50 years: if you could stimulate many multiple sites, and if we knew what patterns to use and when, then we may well be able to conjure up complex ‘thoughts’,”  Professor James said. “Abstract thoughts are harder to read and represent; but not impossible technologically.  We can already do that … we just need to understand the brain better.” Professor Nicolelis hopes brain-to-brain communication will expand the capabilities of  intelligence one day, saying “we cannot even predict what kinds of emergent properties would appear when animals begin interacting as part of a brain-net. In theory, you could imagine that a combination of brains could provide solutions that individual brains cannot achieve by themselves.”

Mind-reading rodents: Scientists show ‘telepathic’ rats can communicate using brain-to-brain connections – The Independent

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

One of the things people have not been able to understand, both morally and biologically, is what drives criminal behavior. When people hear about shootings on the news, such as the one in Colorado at the movie premier of The Dark Night Rises, a question that commonly runs through people’s minds, is “Why on earth would someone do that?”  People seem to ask this question with the assumption that the person is at fault for what they have done. However, can we certainly blame the individual for what they did? David Eagleman, author of Incognito: The Secret Lives of the Brain and neuroscientist at Baylor College of Medicine, attempts to unveil the mysteries that surround this question.

In the United States, people are innocent until proven guilty.  Often, it seems as though a person’s fate is predicated on the motives and intentions behind the criminal act.  At first glance, it is easy to blame someone like The Dark Night Rises shooter for his actions. People would say, “Of course he knew what he was doing.”  A criminal is generally aware of the differences between right and wrong; however, it is possible that he may be influenced by a mental health issue, with an inability to control his impulses.  As Eagleman discusses:

“Biological processes describe most or, some would argue, all of what is going on in our brains.  Given the steering power of our genetics, childhood experiences, environmental toxins, hormones, neurotransmitters, and neural circuitry, enough of our decisions are beyond our explicit control that we are arguably not the ones in charge.”

This statement delves into the question of whether or not culpability is the correct question to be asking in our justice system.  Neuroscientists have studied the many different ways in which small changes in the brain can affect our behavior.  Drugs, for example, act on receptors in the brain, triggering or inhibiting certain chemicals that often cause behavioral or emotional changes. In another case, damage to or chemical changes in a specific cortical area, such as the orbitofrontal cortex, makes it difficult to realistically interpret a social situation, which can cause rash decisions.  These are basic examples of how changes to our brain are significant enough to change how we act.

How can we now apply this neuroscience to the evaluation of criminal behavior? How do we know that all criminals are at fault for their behavior? How do we know that the shooter does not have damage to the brain, and how do we know that the damage did not impact his or her decisions?  Asking these questions is crucial for reforming how criminal cases are managed in terms of punishment and treatment. It can be argued that culpability is not the correct question to be asking in courts because it is not necessarily just to blame someone for a crime over which they had no control. As Eagleman states, “The more we discover about the circuitry of the brain, the more the answers tip away from accusations of indulgence, lack of motivation, and poor discipline — and move toward the details of the biology”.  Neuroscience is an emerging field with research applicable to all of human life. It is the mere beginning of discovering how decisions are made, what drives human behavior, and how much freedom humans have in controlling their own behavior.

Sources:

Incognito by David Eagleman

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

In this post, I attempt to present two major metaphysical accounts of space by Kant and Leibniz, then present some recent findings from cognitive neuroscience about the neural basis of spatial cognition in an attempt to understand more about the nature of space and the possible connection of philosophical theories to empirical observations.

Immanuel Kant’s account of space in his Prolegomena serves as a cornerstone for his thought and comes about in a discussion of the transcendental principles of mathematics that precedes remarks on the possibility of natural science and metaphysics. Kant begins his inquiry concerning the possibility of ‘pure’ mathematics with an appeal to the nature of mathematical knowledge, asserting that it rests upon no empirical basis, and thus is a purely synthetic product of pure reason (§6). He also argues that mathematical knowledge (pure mathematics) has the unique feature of first exhibiting its concepts in a priori intuition which in turn makes judgments in mathematics ‘intuitive’ (§7.281). For Kant, intuition is prior to our sensibility and the activity of reason since the former does not grasp ‘things in themselves,’ but rather only the things that can be perceived by the senses. Thus, what we can perceive is based on the form of our a priori intuition (§9). As such, we are only able to intuit and perceive things in the world within the framework naturally provided by the capabilities and character (literally the under–standing) of our understanding. Kant then takes our intuitions of space (and time) as concepts integral to pure mathematics and as necessary components of our intuition (§10.91).

Kant develops that geometry is based on this pure intuition of space (and arithmetic on that of time) and advances that even after removing all sensations and empirical intuitions, the intuitions of space and time remain, proving them as the a priori intuitions that precede any form of empirical experience or sensation (ibid.103). Thus, our experience of space and the means by which we do geometry is a component of our intuition for Kant and does not require the existence of direct objects of experience. Rather, our awareness of things as they appear in space is woven into our intuition and is a basic characteristic of our experience. Kant goes on to describe space as the “form of outer intuition of our sensibility” in that it is the thing in which we perceive things, i.e. that it is a transcendental condition for sensation (§13.317). By this, we arrive at our understanding of the arrangements of objects in the world not by an empirical encounter, but by the form of our intuition. Therefore, Kant’s account makes geometry an intuitive practice that utilizes a basic component of our pure a priori intuition as opposed to our rational activity. In support, Kant offers that we determine a geometrical concept, e.g. congruency, not through concepts formed by reason, but through relations that are apparent as a result of our pure intuition (ibid.325).

Kant’s theory stands in stark contrast to that of Leibniz, whose account of space is intelligible through arguments in his Discourse on Metaphysics and Monadology. In the former Leibniz foreshadows the concept of the monad in arguing, “each singular substance expresses the universe in its own way,” which develops that the constituent, most fundamental components of reality itself are unique and infinite in number and contain all things present, past and possible (DM.9). In the latter work, Leibniz reiterates that each monad must be different from each other because no two monads can be identical, further establishing the notion of an infinite number of infinite substances that make up the universe (M8-9). Accordingly, objects in the world are made up of monads, which are self contained and distinct from one another. Based on Leibniz’s theory, we arrive at a higher order reality in which everything is separate, distinct and self-contained and therefore, space comes about as a consequence of the existence of objects. That is, when we perceive Leibnizian space, we perceive a thing produced as a result of the existence of two other separate objects.

Leibniz’s account of space also has implications for geometry. By his theory, our perceptions of congruent things for example, become a comparison of two objects made in perception and understood actively by reason. Evidence for this can be found in Leibniz’s arguments concerning physics and causality. Leibniz believes that God constructed the world (with monads) and everything in it in the best possible way (M1,3). As such, the universe carries a predetermined and pre-established order of cause and effect (M6,7) and Leibniz argues that we come to understand nature by finding causes from effects by the use of reason (DM19). Therefore, geometry becomes a rational activity when viewed from a Leibnizian perspective because it is an investigation of that which exists. For Leibniz, we must necessarily invoke our understanding of the nature of objects in the world to do geometry, and this conflicts with the intuitive nature that Kant ascribes to geometry. For Kant, our knowledge (or ‘cognition’) of space is a result of the form of our intuition that comes before sensibility, which makes our understanding of geometry intuitive. For Leibniz, space exists only because discrete objects exist in the world and our understanding of geometry comes from rational manipulations of those objects. Nevertheless, both Kant and Leibniz provide accounts for space that necessarily involve an a priori component rather than perception alone.

Cognitive neuroscientists are now suggesting that spatial cognition is a complex interaction of multiple brain circuits in parallel that make use of both allocentric and egocentric processing of the external world. A pivotally important concept in understanding spatial cognition has been the investigation of representation in the brain. “Representation” is a term that has been used in philosophy for centuries, and science is now using the term to refer to the neural picture of the external world as observed by our brain monitoring and imaging technology. The investigation of representation in the brain essentially involves solving the puzzle of how the world itself is represented physically in the brain. With respect to spatial cognition, the discovery of grid cells in 2005 suggests that a euclidean space is encoded in the brain itself by neurons, and that activation and deactivation of grid cells plays a major role in representing the spatiality of the external world to the perceiver. The discovery of grid cells also suggested a mechanism for the perception of one’s own location that is continually updated by input from the external world, suggesting that, similar to visual perception, the representation of space in the brain itself is an active phenomenon that varies just as much as the visual field.

Most, if not all, of the work on spatial perception and grid cells is performed on rats and conclusions made are inductively applied to humans, which makes us doubt how accurately these mechanisms can apply to the human brain. I say this because while many other studies of physiological phenomena in rats or mice (e.g. those on the cardiovascular and immune systems) may be stronger due to the increased homology to humans present in those systems. In other words, I think that the human and the mouse/rat brain differ quite significantly, perhaps more so than other organs and that this reduces the strength of our inductive conclusions. However, interesting studies are now being performed on humans which place a subject in a virtual maze through a computer program and measure brain activity through noninvasive methods such as functional MRI (fMRI). Many recent studies are pointing to the hippocampus as a major player in way finding and general navigation through virtual mazes, which suggests that our spatial perception is an evolutionarily refined phenomenon, but also one that is fundamental to our basic neural make up. Interestingly, the neural phenomena change when scientists investigate spatial cognition relative to landmarks (i.e. objects) as compared to studies in simple maze navigation. In these object-centric experiments, subjects navigated mazes and were cued with objects present in the virtual environment that they had to collect and place in a distinct virtual location, either at a specific landmark or in a general bounded area. Brain scans in these studies showed both hippocampal and striatal activation during the performed tasks, with hippocampal activity associated with the boundary task and striatal activity associated with the landmark task. Further, separate studies in rats performing similar spatial boundary tasks reveal that the activation of hippocampal “place cells” fire in boundary-space tasks, which scientists think are creating a matched representation of distances and angles relative to the boundaries in the visual field. Results from striatal activation are still unclear and are being more closely investigated. It has also been suggested that the hippocampal and striatal circuits act in parallel rather than in series or in combination. This makes sense given that spatial cognition may involve both boundary and landmark elements, as when we have to hammer a nail into a specific location or plug something into a power outlet.

Relating the philosophy and neuroscience presented in this post, it seems that both Kantian and Leibnizian conceptions of space are compatible with neuroscientific findings about spatial cognition. Kant’s theory applies to the current understanding of hippocampal, boundary influenced tasks in that both suggest a holistic conception of space – that is, space can be understood as object independent. On the other hand, Leibnizian conceptions of space and the landmark results suggest a more object-dependent framework for spatial cognition. As spatial cognition and perception are our most direct means to accessing and interacting with the external world, both scientists and philosophers of the future ought to work together on this enormously complex problem in an effort to postulate how spatial phenomena as presented to us by the mind relate to neural phenomena in the brain. Perhaps then we will move closer to filling the explanatory gap between the mind and brain.

Prolegomena – Kant
Discourse on Metaphysics – Leibniz
The Monadology – Leibniz
Spatial Cognition and the Brain – Neil Burgess

We’ve all seen it happen, marveled at the constancy, and even blamed the friends around us for our own personal breathing. Does this sound strange? I am talking of course about contagious yawning; this is the phenomenon that seeing someone yawn will cause you to immediately do the same. But why, and for that matter, why even yawn in the first place?

More and more researchers seem to agree that we yawn (actually all vertebrates yawn) as a means of brain thermoregulation. This seems somewhat fantastical at first, but let’s look at the evidence. We have associated yawning for years with being tired. Many of us wake up each morning, yawn and stretch as we get out of bed; we are still tired, right? Or better yet, you’re sitting in the back of your 90 minute lecture, and although you’ve been trying to be more attentive this semester, you can’t help but sit, idly yawning and wishing you were back in your bed for a nap. This theory of thermoregulation actually fits perfectly with us yawning when we are tired.

Thermoregulation has long been attributed to sleep. Sleep is believed to allow our body to properly regulate its temperature, so it should come as no surprise that we yawn—or cool our brains—when we are tired. Without sleep, our bodies have difficulties regulating their temperatures; meaning as we get more tired, our brains could be getting hotter. This simple mechanism of yawning would then allow our bodies to compensate for thermoregulatory failure caused by a lack of sleep.

Further evidence would even allow us to predict the frequency of contagious yawning based upon the ambient temperature. Researchers have found that individuals were more likely to yawn in cooler temperatures (below body temperature) than warmer (above body) temperatures. The longer they were exposed to this ambient temperature, the more they followed this tendency of yawning at the lower temperatures. If you don’t believe this, test it yourself. The next time you are outside in the summer (or in a hot room for a prolonged period of time) think about how many times you yawn and then do the same in colder temperatures. The frequency should be significantly lower in the warm, summer weather, especially the longer you are exposed to it, than in the cold winter.

So if we agree that yawning is the brain’s way of cooling down, why then do we need to yawn contagiously? Is our brain just allowing us to remind others to stay cool? This is doubtful, and researchers cannot actually completely answer this question yet. However, some evidence suggests that contagious yawning serves a function of self-processing and is a part of a neural network that is also involved in empathy.

So the next time you yawn (and I’m sure you did a few times while reading this) simply remember that your brain just needs a quick flux of air to cool off, so it can continue to perform the millions of incredible tasks you make it do every minute of every day.

Really? The Claim: Yawning Cools the Brain – NY Times

Contagious Yawning and Seasonal Climate Variation – Frontiers in Evolutionary Neuroscience

Yawning and Stretching Predict Brain Temperature Changes in Rats: Support for the Thermoregulatory Hypothesis – Frontiers in Evolutionary Neuroscience

Thermoregulation and Sleep – Annals of the New York Academy of Sciences

http://onlinelibrary.wiley.com/doi/10.1002/cphy.cp040259/full

Sleep, Thermoregulation, and Circadian Rhythms – Comprehensive Physiology

Zombies are terrifying creatures. The most panic-inducing aspect of their completely factual existence among us is that they have a taste for human blood and they will do anything  to get to it. Recently, the Zombie Research Society (ZRS) has been attempting to scan (with some difficulty due to the fact that zombies aren’t huge fans of staying still in MRIs) and create a map of the zombie brain. A leading researcher in ZRS, Dr. Bradley Voytek, lectured about these terrors at Nerd Night SF. In his presentation he gives a medical term to describe the zombie condition: “consciousness deficit hypoactivity disorder (CDHD)- the loss of rational voluntary and conscious behavior replaced by delusional/impulsive aggression, stimulus-driven attention, and the inability to coordinate motor or linguistic behaviors.” So with those messy scans and some preliminary facts we know about the living dead, researchers such as Dr. Voytek have been able to come up with multiple images of what a real zombie brain must look like.

These facts are taken from real-life documentaries of zombie pandemics, such as Night of the Living Dead, Shaun of the Dead, and 28 Days Later. So let’s review the characteristics of zombies the ZRS has established by examining these accounts.

1. According to Major West in 28 Days Later, zombies “are futureless” and therefore no complicated cognitive behaviors would occur. That means no emotion, no love, and therefore no frontal lobe, which is probably why zombies are willing and able to devour humans without remorse.
2. Memory deficiencies occur in zombies, signifying a loss of the hippocampus. We often see short-term and even long-term loss (explaining why they will attack family and old friends). Yet researchers hypothesize there may be some long-term memory intact by examining the story of Shaun of the Dead, primarily the final scene where we see Shaun and his newly turned zombie pal playing video games like old times.
3. Illustrated by their stiff gait, zombies clearly have motor deficits (cerebellar ataxia). This means that the cerebellum has atrophied and they have significantly less area to their cerebellum than the normal human.
4. Zombies also exhibit extreme aggression and a lack of impulse control. These two symptoms can be explained by a lesion to the orbital frontal cortex, which regulates the amygdala, which then connects to the periaqueductal gray, the hypothalamus, and the thalamus. These parts of the brain control rage, fear, agression etc. A lesion on the orbital frontal cortex will cease all regulation of the amygdala and therefore we will observe a drastic increase in aggression and impulse control.
5. And finally we see a language deficit. Very rarely are zombies able to mutter more than a moan of “BRAINNNNSSSS!!!” (which is still relatively complex for their neuroanatomy). Due to this behavior we are able to discern that zombies lack Wernicke’s area (to comprehend speech) and Broca’s area (to relay thoughts through speech).

I’m guessing that you’re thinking Alright this is all fine and dandy, but when I’m attacked by a zombie how do I escape alive? Well you’re probably going to want to run faster and climb higher than the person next to you. Considering their memory deficit, you can hide for long enough and they’ll just forget about you and move on to the next prospective dinner. And remember: trying to talk or reason with a zombie is completely useless.

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

In June 2010, Mauricio Vargas and colleagues from Stanford University School of Medicine reported research in Proceedings of the National Academy of Sciences showing that endogenous antibodies play an important role in repairing peripheral nervous system (PNS) damage. Antibodies are a principal part of the adaptive immune response to infection, but this research suggested that antibodies are also able to clear degenerating myelin which inhibits axon regeneration, akin to a homeostasis function. This repair was only present after PNS injury, whereas myelin debris remained in the central nervous system (CNS) white matter for years. The well known blood-brain barrier concurs with this separation in responses, as it is understood to be impermeable to large proteins such as antibodies.

Various new studies, however, have shown that behavior, mood, and memory can all be influenced by aspects of the immune system, suggesting that antibodies can somehow infiltrate the brain.

Sammy Maloney was a happy and outgoing 12-year-old boy. In 2002, however, his mother started to notice curious deviations in his personality. In six months, he underwent complete mental deterioration and was diagnosed with obsessive compulsive disorder and Tourette’s syndrome. Shortly afterwards, he was found to be harboring a streptococcal infection, although he exhibited no physical symptoms of one. Interestingly, when he started taking the prescribed antibiotics, his behavior markedly improved.

Madeline Cunningham at the University of Oklahoma has spent several years investigating various behavioral disorders associated with streptococcal infections. Cunningham has shown that antibodies against one group of streptococcal bacteria are able to bind to a site in the brain that controls movement, and consequently trigger the release of dopamine. This could explain the emotional disturbances associated with these types of disorders (1).

Studies also suggest that an activated immune system has other perceivable effects on the nervous system. For example, Jonathan Kipnis of the University of Virginia and his colleagues have shown that learning triggers a stress response in the brain, which causes CD4 cells, a type of T lymphocytes, to gather at the meninges and release interleukin-4. IL-4 switches off the stress response and causes a release of brain-derived neurotrophic factor, which facilitates memory formation. Interestingly, cancer patients treated with chemotherapy drugs often experience various cognitive defects and some memory loss.  This is commonly called “chemobrain”, and these studies raise the possibility that it is a consequence of immunosuppression. Finally, an immune response against Mycobacterium vaccae has been shown to improve mood by causing neurons in the prefrontal cortex to release excess seratonin.

So it could be that the blood-brain barrier is kind of leaky after all. Understanding the connections between the immune system and the brain could lead to all sorts of ingenious treatments for various disorders. Perhaps those scientists at Stanford will utilize antibodies to develop a treatment for central nervous system repair. Perhaps we’ll one day be faced with immuno-emotive treatments for depression. Who knows? Anything is possible when a long-standing “truth” turns out not to be absolute – I’m optimistic since scientific advancement is often built on the refinement of prior knowledge.

Happiness is Catching – New Scientist

Endogenous Antibodies Promote Rapid Myelin Clearance and Effective Axon Regeneration after Nerve Injury – Proceedings of the National Academy of Sciences

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Footnote:

(1) Antibodies raised against the Streptococcal M protein and human myocardial tissue, and Guillain-Barre syndrome in response to Campylobacter infection, are well studied examples of cross-reactivity between anti-pathogen antibodies with host tissues.