“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

If you were to ask any reasonable person (or reasonable physicist) how quantum mechanics works, 9 out of 10 times he/she would probably give you the same answer: magic. Yes, the field of quantum physics is known far and wide across academia as being both pretty difficult (lots of math) and pretty confusing (it just seems like it makes stuff up as it goes). However, despite all the tedium and wizardry that surrounds quantum mechanics, if you look hard enough at the many applications that the science has to offer to other fields, you may quickly come to find that it is also pretty dang awesome. Indeed, even the field of neuroscience has experienced some cross over with quantum physics in an attempt to explain many of the mysteries of the mind. But, what specific oddities about the brain are so opaque that they would need something as complex as physics’ black magic to explain them?

What are the quantum mysteries of the mind?

Let’s consider for a second some of the basic principles behind synaptic plasticity in neurons. As any molecular or cognitive neuroscientist will tell you that the plastic nature of connections in the brain is great, mainly because it lets your neurons tweak and strength certain essential inputs and outputs, and remove (or “prune”) the ones that are not so essential. If they were to go on, they would probably also tell you that neurons can select the neuron-to-neuron connections that they preserve and remove based on the strength of the signals that are being conducted through all those different connections.

Basic model of Hebbian learning/synaptic plasticity: Cells that signal together create strong connections and stabilize; cells that signal weakly do not stabilize and are eventually removed

In short (and to quote Donald Hebb), “neurons that fire together, wire together” and all other signals/connections fade away over time. This all seems pretty intuitive, of course neurons want to talk with other neurons from which they can actually get a decent signal! The exact mechanism by which this occurs, however, is not altogether intuitive. Indeed, since this form of wiring is so important in the brain for functions such as learning, memory and general cell-to-cell communication, many neuroscientists are left asking just what motivates it. More importantly though, if this event is essential to learning and memory formation in the brain, do you have any control over how your brain decides when to fire and what to wire to?

Quantum particles: impossibly small bundles of subatomic species and energy, or highly concentrated balls of pixie dust?

Quantum theorists have attempted to explain this “firing and wiring” effect, along with the influence that consciousness holds over what stays and what goes, by citing the quantum zeno effect, a bizarre phenomenon first observed by particle physicists who were attempting to observe the spontaneous decay of uranium. During their experiment, these physicists would continuously make observations of the radioactive uranium particles to observe the degradation. Amazingly, the researchers soon began to realize that whenever they made continuous observations of the uranium, it would cease to decay and instead appeared to “freeze” itself in a stable state! To ensure that they were all not crazy (or suffering some form of radiation poisoning), the initial research team shared these results with several colleagues who replicated them and observed the exact same thing! It is now actually a relatively accepted fact in the realm of quantum mechanics that rapid repeated measures of a quantal system will slow the fluctuation between quantal states of any species within that system. Quite literally, this phenomenon seems to validate the old saying that “a watched pot never boils”!

Do neurons, per say, utilize quantum locking as a defensive mechanism while stalking intergalactic prey, or perhaps just to remain in one specific state for long periods of time (had to give a shout out to the Doctor Who fans in this article)?

But how does all this “quantum locking” come back to neuroscience, and to cells firing and wiring together for that matter? According to a new theory floating around that combines both quantum mechanics and cognitive neuroscience, the determination of neural circuit formation depends entirely on the quantum zeno effect. The way the effect is achieved in the brain isn’t through being camera shy like uranium, but instead through simply being able to focus one’s attention. As the theory states, the mental act of focusing attention can stabilize the brain circuits that are associated with whatever one is focusing on. So, if you were to receive a prick on your finger and you were then to focus all your attention on it, the current state of your brain at the time would be maintained in order to allow you to interpret the signaling associated with that event (i.e. feeling pain). Thus, in terms of promoting Hebbian learning: the more you are able to direct your attention to specific stimuli, the more readily all the neurons involved in the current response to that stimuli will be able to fire and synapse to one another (thus promoting the strengthening and solidifying of specific neural circuits)! While this model is definitely not without its holes, the quantum zeno hypothesis does provide a very interesting way to consider how the brain may handle bouts of conscious learning (or self-directed plasticity) and is able to stabilize certain synaptic pathways. If anything, it hopefully provides us with a more magical interpretation of the brain and how it completes its many whimsical tasks!

Does Quantum Mechanics Play a Non-trivial Role in Life? – Biosystems

Quantum Physics in neuroscience and psychology: a neurophysical model of mind-brain interaction – The Philosophical Transactions of the Royal Society

The Quantum Zeno Paradox or Effect – Mass (Blog of Carl Brannen)

What’s attention got to do with it? Quantum physics of the brain in mediation – Brains on Purpose

Why Much of Recent Neuroscience Research is a Waste of Money – PsychCentral

Most would agree that the most important of our basic senses is sight. Without it, many basic forms of communication fall apart, the vibrance of the world around us dulls, and our understanding and ability to sense the complexity of the physical world diminishes. Without the ability to see, it would logically be impossible to portray our surroundings artistically in a coherent and visually realistic manner…

…wait…what?

Esref was born without the privilege of sight. As a result, he never developed the thalamo-cortical projections from the lateral geniculate nucleus (LGN) to the primary visual cortex necessary for sight perception. However, instead of letting his occipital lobe go to waste, Esref’s brain adapted by using that same cortical real estate for other senses, primarily touch.

With Esref’s enhanced sense of touch he claims he can, “see more with his fingers than sighted people can see with their eyes.” A bold statement: after all, Esref has no idea what seeing is like. Conversely, sighted people don’t know what the sense of touch is like when the visual cortex becomes involved, so can we really deny his claim? The circular nature of this subjective discussion renders both opinions null but it does raise the question: is a subjective experience a product of the sensory modality involved or is it a product of the cortical area involved? And what exactly is Esref subjectively perceiving when he is feeling his way through a landscape? Is it as vivid as the subjective experience that sighted people perceive? It seems this question is impossible to resolve but seeing the landscapes Esref paints makes one believe that he is indeed sensing the world just as vividly as the rest of us.

Esref provides a new perspective on perception which throws a kink into anyone’s previously held beliefs about subjective experience and raises many internal questions. Personally, this new perspective leaves me with one question in particular: we can all agree that the 2003 blockbuster Daredevil was horrible, but wasn’t the rooftop rain scene where the blind Ben Affleck uses the sound of the raindrops on Jennifer Garner’s face to create a mental construct of her one of the most forward thinking, cognitive science-inspired scenes in all of cinematography?

Foreshortening, convergence and drawings from a blind adult – Perception

"Dude, my action potentials are on fire right now."

• Are you aging and senile?
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• Are you simply dissatisfied with your cognitive strength?

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As we age, our brains age with us, slowly deteriorating over time. For the fast-paced lives we now lead however, having mediocre cognitive abilities just doesn’t cut it. Famed neuroscientist, brain-plasticity connoisseur, and new businessman Michael Merzenich has engineered a series of “brain fitness” activities that are claimed to help individuals keep their minds in tip-top shape.

Merzenich’s Posit Science program is based on neuroplasticity, the ability of the brain to reorganize itself. While cortical reorganization is a remarkable asset of the brain to adapt to change, it may also be detrimental when the brain is not utilized to its full potential. Dr. Merzenich asserts that in order to maintain neurological skill throughout adulthood, individuals must continue to train the various cognitive-sensory facets of the mind.

The clinically supported Posit Science program offers a multi-modal, total brain training package composed of both an auditory skill and a visual skill program. This training includes a series of six computer-based programs specifically designed to improve the brain’s auditory-visual processing and perceptive abilities.

Currently, Posit Science is looking to broaden the applicability of its products by venturing into the world of social networking. The company has recently developed and launched a networking site called “Brain Odyssey,” through which individuals can work together to solve mysteries and virtually explore cities throughout the world, all while collaborating on cognitive training tasks.

But Wait…!

In addition to offering a mental fitness program, the company website also features several brain games as well as a few “brain tests” as an informal way of testing one’s cognitive prowess, free of charge.

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A “better brains” collective launches to improve cognition of the masses – Scientific American