Tagged: neurons
Don’t Panic! – Mice Aren’t Actually the Smartest
“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.
"Stroking" Neurons
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.
The Present State of Brain-Machine Interfaces
We live in an era where the rapid advances in technology are constantly changing how we perceive and interact with the world around us. The question on everyone's mind is always "what's next?" The answer: brain-machine interfaces. For the average consumer, brain-computer interfaces are becoming increasingly available on the mass market and their current uses offer a wide range of fascinating opportunities.
A company that's been in the news a lot lately is NeuroVigil. Their product known as the iBrain has been used to help world-renowned astrophysicist Steven Hawking communicate with a computer simply by thinking. Hawking, who suffers from Lou Gehrig's disease, developed his own solution to allow him to speak by twitching his cheek to select words from a computer. In its current state, the iBrain is still slower than Hawking's solution, but NeuroVigil's founder MD Philip Low hopes that it will eventually be possible to read thoughts aloud. NeuroVigil also made the news by signing a contract with Roche, a major Swiss pharmaceutical company, to use the iBrain in clinical studies for evaluating drugs for neurological diseases.
Philip Low with the iBrain
High Definition Fiber Tracking
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. More
Decisions, Decisions
What kind of day would you rather have?
A decision is a fact of life. Both the good and the bad, the wrong and the right, one seemingly unjust turn waiting to happen amid the uncertain crossroads of life. Lets be honest, making a decision will always provide the answer, that is the ideal outcome, nothing goes wrong, everything is perfect, happily ever after. On the contrary, there is the undesirable result, which you would rather keep trapped in a cage and have thrown into a river in order to prevent 'it' from ruining your party. Now with making a decision comes the possibility for his arch-nemesis "regret" to appear in the equation. Lets look at it this way, if your friend 'decision' calls and asks if you want to see this movie which you assume is going to be terrible, you'd probably say "No," thereby rejecting 'decision.' A week later 'regret' sends you a letter saying 'decision' went to the movie that day, saw your partner, they both hit it off, 'decision' slept with them, and now your partner never wants to see you again. See why you should have gone to the movie! That my friends is exactly, to a tee, the comic strip you will see when you look up decision in the dictionary. More
Can the Mind Control the Brain?
Research has been conducted that proves that our thoughts can control the rate of firing of neurons in our brain. This research reveals the crucial advancement of brain-operated machines in the field. John P. Donoghue at Brown University has conducted research that uses neural interface systems (NISs) to aid paraplegics. NISs allows people to control artificial limbs; individuals simply need to think about commanding their artificial limbs and signals are sent down from their brain to control the movement of these limbs! This great feat is not the only applicable result of current research done by brain-machine interfaces. Dr. Frank Guenther of Boston University uses implanted electrodes in a part of the brain that controls speech to tentatively give a voice back to those who have been struck mute by brain injuries. The signals produced from these electrodes are sent wirelessly to a machine that is able to synthesize and interpret these signals into speech. This is specifically useful for patients suffering from locked in syndrome, wherein an individual with a perfectly normal brain is unable to communicate due to specific brain damage, and thus allowing these individuals to communicate with the world! These discoveries are not only incredibly useful, but they also reveal the astonishing feats that the field of computational neuroscience is accomplishing in the world today.
On-line, voluntary control of human temporal lobe neurons
Somewhere Over the Brainbow
Because of the brain's amazing and incomprehensible complexity, there are billions of neurons that connect and network all the major areas of the brain with the small intricate parts as well. So how can we distinguish one of these neurons from the billions of others?
Well, within the past five years more advanced techniques have been discovered and used on various organisms. The most prevalent, and probably the most revolutionary, has been staining. This process was pioneered in the late nineteenth century by Camillo Golgi and allowed for the staining of whole, random cells.
Since then, much progress has been made and today the viewing of even more complex and minute parts that make up the brain is possible. One extraordinary technique was developed by a team of Harvard researchers a few years ago, and it is truly beautiful.
Known as the Brainbow technique, these investigators were able to use genetics to visualize complete neuronal circuits in unprecedented detail. Up to four differently colored fluorescent proteins were used, generating a palette of 100 distinct hues that labeled individual neurons.
Here are the fluorescent proteins in their full glory illuminating the many neurons that make up the brain of a mouse. More
