Brainbeauty: Did you know chickens ‘one-up’ humans in ability to see color?
The retina contains two types of cells, rods and cones. Rods handle low light vision where as cones handle color vision and detail. A series of complex chemical reactions occurs when light contacts these two types of cells. The number and ratio of rods to cones varies among species, dependent on whether an animal is primarily diurnal or nocturnal.
Birds have five types of cones including four single cones and a double cone thought to mediate achromatic motion perception. Birds have a cone photoreceptor for violet/ultraviolet light in addition to the red, blue and green single cone cells that humans share. Much however is still unknown about the spatial organization of avian cones and the adaptive significance.
The vibrancy of avian color vision is currently thought to be a result of not experiencing an evolutionary nocturnal period. In contrast, mammals spent millennia as nocturnal organisms and developed a high density of rod photoreceptors. Since chickens possess minimal rods, mammals still have the ‘one-up’ in the dark.
Brainstorm: Neuroscience Essentials for Learning Design
One of the most fertile areas of investigation into brain processes and properties is in the area of learning. Most of what we now know became current after most of our professional educators were trained. Indeed, you could argue that the whole of our education and training systems have been built around false notions and outdated paradigms how the brain functions.
…one of their significant claims is that learning “seems the most broadly and consistently successful cognitive enhancer of all.” What this means, is that education can build an individual’s cognitive reserve and resilience and that will help that person adapt to stressful and traumatic events as well as normal ageing. This reserve and resilience can be built up at any point during life.
…from this information is possible to adduce seven design principles for corporate learning based around well researched and proven data emerging from neuroscience:
1. Engage the entire learning cycle. Make time for reflection, creation and active testing as well as absorbing new information.
2. Make connections with the learners’ prior knowledge and experience.
3. Create opportunities for social engagement and interaction part of the learning process.
4. Engage both feeling and thinking. Learning needs in motion as well as intellect.
5. Actively attend to attention. It is important to gain, hold and focus the learners’ attention for effective learning to take place. We simply do not pay attention to boring things.
6. Engage the maximum number of senses possible, especially visual, when designing learning.
7. Exercise boosts brainpower as increases oxygen flow to the brain. Keep people active at least part of their learning day and encourage people to remain active throughout their lives.
John Medina in his book “Brain Rules” is impatient with how slowly the lessons of neuroscience percolated into learning.
“If you wanted to create an educational environment that was directly opposed to what the brain was good at doing, probably you would design something like a classroom. If you wanted to create a business environment that was directly opposed what the brain was good at doing, you would probably design something like the cubicle…”
(Source: Nigel Paine, www.NigelPaine.com)
Brainbeauty: Calcium reveals connections between neurons
Neuroscientists used calcium imaging to label these pyramidal cells in the brain
"Performing any kind of brain function requires many neurons in different parts of the brain to communicate with each other. They achieve this communication by sending electrical signals, triggering an influx of calcium ions into active cells. Using dyes that bind to calcium, researchers have imaged neural activity in neurons. However, the brain contains thousands of cell types, each with distinct functions, and the dye is taken up nonselectively by all cells, making it impossible to pinpoint calcium in specific cell types with this approach.
To overcome this, the MIT-led team created a calcium-imaging system that can be targeted to specific cell types, using a type of green fluorescent protein (GFP). Junichi Nakai of Saitama University in Japan first developed a GFP that is activated when it binds to calcium, and. Loren Looger of the Howard Hughes Medical Institute, modified the protein so its signal is strong enough to use in living animals.
The MIT researchers then genetically engineered mice to express this protein in a type of neuron known as pyramidal cells, by pairing the gene with a regulatory DNA sequence that is only active in those cells. Using two-photon microscopy to image the cells at high speed and high resolution, the researchers can identify pyramidal cells that are active when the brain is performing a specific task or responding to a certain stimulus.”
(Article: Anne Trafton, Image: Quen Chen)
Acrylic painting of Primary cells isolated from embryonic rat striatum and allowed to differentiate into neurons.
Referenced from microscopic photographies of Keck Lab, University of Wisconsin
The primary cell is the cell that is cultured from the primary subject, in this case a rat striatum (part of the brain that “facilitates and balances motivation with both higher-level and lower-level functions, such as inhibiting one’s behavior in a complex social interaction and fine-motor functions of inhibiting small voluntary movement”) in order to allow cell differentiation to take place (The normal process by which a less specialized cell develops or matures to possess a more distinct form and function. - in this case a neuron).
Brainbeauty: Generating and Imaging Multicolor Brainbow Mice
Fluorescent microscopy works by labeling cells with specific markers that cause them to glow certain colors when bathed in a special wash of chemical agents (fluorophores). These “markers” are usually genetic markers, and by tinkering with the genome of a host animal, the markers – and thus the colors produced by cells under the microscope – can be altered. Driven by a desire to map the vast web of neural connections in the mouse brain, Jeff Lichtman and his team at Harvard developed a fluorescent staining technique affording them a sizable palette with which to paint neurons.
The genetic system they used is called the Cre/lox system. Cre is an enzyme responsible for deleting sections of DNA that are adjacent to lox alleles. By splicing in a handful genetic markers that are responsible for different fluorescent colors (green, yellow, red, etc) in various places near the lox sites, a game of genetic roulette was played – depending on the position of different fluorescent color-producing genes in relation to the lox enzymes, a myriad of colors would ultimately be produced in the target neurons (i.e. red green green yellow, red red red green, red yellow yellow yellow, etc).
Lichtman cleverly dubs the technique “Brainbow.” The gallery above shows a sampling of the lush, elegant views of neural networks provided by the Brainbow technique.
(Source: Sam McDougle, The Beautiful Brain; Images: Jean Livet, Tamily A. Weissman, Hyuno Kang, Ryan W. Draft, Ju Lu, Robyn A. Bennis, Joshua R. Sanes & Jeff W. Lichtman.)
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Brainstorm: The Neuroscience of Imagination
Understanding how imagination works could be the key to daydreaming yourself into a sharper, more creative person…
"…when your imagination is at work, networks in the brain interact with one another. If you lit up those network regions in a brain scan, they might look something like a spotted cowhide. Three large-scale brain networks in particular can help understand brain activity involved in creative thinking, according to Kaufman:
The Executive Action Network: If you need laser-focused attention on something—be it a complex presentation or a problem that requires your working memory, you’re recruiting the executive attention network in your brain.
The Default Network: When you’re remembering, thinking about the future or imagining alternative scenarios, you’re activating the default network; what Kaufman calls the “imagination network.” This is also at work during social interactions when, say, you’re trying to imagine what someone else is thinking.
The Salience Network: This network monitors both external events and your internal stream of consciousness, moving quickly between the two depending on which is most relevant in the moment. It gathers all of the information coming at you and prioritizes it, sending signals to the brain about what it ought to process first.
…According to Berns: “The surest way to provoke the imagination … is to seek out environments you have no experience with. … Novel experiences are so effective at unleashing the imagination because they force the perceptual system out of categorization, the tendency of the brain to take shortcuts.”
(Source: Jane Porter, FastCompany.com)
Brainstorm: The Neuroscience of Effective Leadership
What do you get when you cross your grandmother’s advice with the latest research in neuroscience?
Don’t be quick to judge: Our brains play a simple trick on us all the time: we like to surround ourselves with people who think like we do. An effective leader will keep the book open rather than judge by its cover. That strategy comes through in subtle ways such as asking off-beat questions during job interviews to allowing themselves to receive ideas from anyone on the staff…
Take winning and losing in stride: …According to research… you actually get better outcomes for decisions you face repeatedly when you approach them as a portfolio rather than individually… Some of the most successful social entrepreneurs view their failures as an essential part of their journey towards achieving their goals…
Take a breather: Stress is the underlying cause of 60% of illness and disease. A simple pause to reflect and recharge in the middle of a hectic day can boost brain power so you’re more likely to retain new ideas… A five-minute meditation can be all the encouragement your prefrontal cortex needs to shift into its smart state.
Wall it off: …Research shows that stepping quite literally, out of the box of an office, does wonders to clear the mind and spark creativity. But don’t take our word for it.
Flip a coin: Sometimes, our smarts get in the way of decision making… A wise leader pays attention to their gut reaction after the [coin] toss. By attending to the physical sensations at the result of the toss, the body is fast-tracking decision-making to the brain; that’s just neuroscience telling you to trust your intuition.
It’s nice to be important, but important to be nice: …Managers who get high marks for engaging their teams toss competition out and focus instead on giving and getting honest feedback. They provide opportunities for growth and encourage inclusive cultures that let ideas trump seniority.
(Source: By Lydia Dishman, FastCompany.com)
Brainbeauty: Medium spiny neurons
Medium spiny neurons (MSNs) are indeed “medium sized” with a cell body between 15 and 18 μm and dendritic fields that range from 200 to 300 μm in diameter. These neurons are marked by expansive dendrite trees with an abundant scattering of short spines. MSNs are the primary output of the striatum, a subcortical part of the forebrain that is the chief input region of the basal ganglia system. MSNs make up about 96% of the striatum and receive input from cortex, thalamus, and substantia nigra (1).
MSNs are GABAergic and therefore have an inhibitory influence on the neurons they project to, and are mostly modulated by dopamine and glutamate. Numerous tonically active cholinergic interneurons are closely positioned to the medium spiny neurons’ cell body in order to closely regulate their volatility. As a result, medium spiny neurons are normally quiet and tend not to exhibit spontaneous activity unless adequately activated (2).
Within the basal ganglia, complex neuronal loops are formed by MSNs that are important for the control of action, cognition, and emotion. In particular, these neurons have a critical role in motor control, habit formation, and motivated behavior. Further research of the medium spiny neuron is paramount due to their role in major neuropsychiatric disorders stretching from Parkinson’s disease and Huntington’s disease to schizophrenia and addiction (3).
Neuronews: Brain connections may explain why girls mature faster
Newcastle University scientists have discovered that as the brain re-organizes connections throughout our life, the process begins earlier in girls which may explain why they mature faster during the teenage years.
As we grow older, our brains undergo a major reorganization reducing the connections in the brain. Studying people up to the age of 40, scientists led by Dr Marcus Kaiser and Ms Sol Lim at Newcastle University found that while overall connections in the brain get streamlined, long-distance connections that are crucial for integrating information are preserved.
The researchers suspect this newly-discovered selective process might explain why brain function does not deteriorate – and indeed improves –during this pruning of the network. Interestingly, they also found that these changes occurred earlier in females than in males.
… The researchers at Newcastle, Glasgow and Seoul Universities evaluated the scans of 121 healthy participants between the ages of 4 and 40 years as this is where the major connectivity changes can be seen during this period of maturation and improvement in the brain… Using a non-invasive technique called diffusion tensor imaging – a special measurement protocol for Magnetic Resonance Imaging (MRI) scanners – they demonstrated that fibres are overall getting pruned that period. However, they found that not all projections (long-range connections) between brain regions are affected to the same extent; changes were influenced differently depending on the types of connections.
Projections that are preserved were short-cuts that quickly link different processing modules, e.g. for vision and sound, and allow fast information transfer and synchronous processing. Changes in these connections have been found in many developmental brain disorders including autism, epilepsy and schizophrenia.
The researchers have demonstrated for the first time that the loss of white matter fibres between brain regions is a highly selective process – a phenomenon they call preferential detachment. They show that connections between distant brain regions, between brain hemispheres, and between processing modules lose fewer nerve fibres during brain maturation than expected. The researchers say this may explain how we retain a stable brain network during brain maturation.
Commenting on the fact that these changes occurred earlier in females than males, Ms Sol Lim explains: “The loss of connectivity during brain development can actually help to improve brain function by reorganizing the network more efficiently. Say instead of talking to many people at random, asking a couple of people who have lived in the area for a long time is the most efficient way to know your way. In a similar way, reducing some projections in the brain helps to focus on essential information.”
(News & Image Source: Newcastle University)
A new study by Wellesley College neuroscientists is the first to directly compare brain responses to faces and objects with responses to colors. The paper, by Bevil Conway, Wellesley Associate Professor of Neuroscience, and Rosa Lafer-Sousa, a 2009 Wellesley graduate currently studying in the Brain and Cognitive Sciences program at MIT, reveals new information about how the brain’s inferior temporal cortex processes information.
Located at the base of the brain, the inferior temporal cortex (IT) is a large expanse of tissue that has been shown to be critical for object perception. This region of the brain is commonly divided into posterior, central, and anterior parts, but it remains unclear as to whether these partitions constitute distinct areas. An existing, popular theory is that the parts represent a hierarchical organization of information processing, a notion that has previously been supported by functional magnetic resonance imaging (fMRI) in monkeys.
For their study, Conway and Lafer-Sousa used non-invasive fMRI to measure responses across the brains of rhesus monkeys to a range of different stimuli and obtained responses to images of objects, faces, places and colored stripes. “The technique enabled us to determine the spatial distribution of responses across the brain, and has been useful in figuring out how the visual brain is organized,” Conway said.
… “Shape and color are both properties of objects and are processed by the parts of the brain known to be important for detecting and discriminating objects. However, the way this part of brain is organized has not been clear, for example, is color computed by different parts of this region than those that compute shape?” The answer to this question, Conway said, has deep implications for understanding the general computational principles used by the brain and how the brain evolved.
"Our work showed that, to a large extent, color and faces are handled by separate, parallel streams, and that these pieces of information are processed by connected, serial stages," Conway said. "One can imagine the processing as an assembly line, where some aspect of faces – and some aspect of color – is computed first. The output is then sent to another region downstream that makes a subsequent computation."
… “The most striking aspect of the study is what it reveals about the precision of the organization of the brain. We often think that because the brain consists of billions of neurons, that at some level it must be quite variable how the neurons are organized,” Conway said. “The study shows that there is a remarkable precision in organization of the neural circuits for high-level vision, which will make tractable many questions bridging cognitive science and systems neuroscience.”
… The researchers note that it remains unclear whether the organizational principles found in humans apply to monkeys, an important issue that bears on cortical evolution. However, their results suggest that the IT comprises parallel, multi-stage processing networks subject to one organizing principle.”
(Source: Medical Xpress, Image Credit: Bevil R. Conway, Wellesley College)
Gamma-aminobutyric acid (GABA) deficits have been implicated in schizophrenia and depression. In schizophrenia, deficits have been particularly well-described for a subtype of GABA neuron, the parvalbumin fast-spiking interneurons. The activity of these neurons is critical for proper cognitive and emotional functioning.
…Dr. Kim Do and collaborators, from the Center for Psychiatric Neurosciences of Lausanne University in Switzerland, have worked many years on the hypothesis that one of the causes of schizophrenia is related to vulnerability genes/factors leading to oxidative stress. These oxidative stresses can be due to infections, inflammations, traumas or psychosocial stress occurring during typical brain development, meaning that at-risk subjects are particularly exposed during childhood and adolescence, but not once they reach adulthood.
Their study was performed with mice deficient in glutathione, a molecule essential for cellular protection against oxidations, leaving their neurons more exposed to the deleterious effects of oxidative stress. Under those conditions, they found that the parvalbumin neurons were impaired in the brains of mice that were stressed when they were young. These impairments persisted through their life. Interestingly, the same stresses applied to adults had no effect on their parvalbumin neurons.
Most strikingly, mice treated with the antioxidant N-acetylcysteine, from before birth and onwards, were fully protected against these negative consequences on parvalbumin neurons….
(Source: Medical Xpress)
”Neuroscience over the next 50 years is going to introduce things that are mind-blowing.” - David Eagleman
Brainstorm: David Eagleman: 'We won't die – our consciousness will live forever on the internet'
Seeing God as a microbe is just one way the neuroscientist’s debut novel gets to grips with the afterlife.
In one of the stories in David Eagleman’s first work of fiction, Sum: Forty Tales from the Afterlives (Canongate), God consoles himself for the mess that is humankind by reading Mary Shelley’s Frankenstein. In another, people pay vast sums to ensure the glamorous afterlife they desire, only to find themselves marooned in the most cliched version of heaven, where they sit on white clouds, clad in ill-fitting white robes, strumming harps.
By day, Eagleman is a neuroscientist at Baylor College of Medicine in Houston, Texas, where he specialises in the study of time perception and synesthesia. He also directs the college’s Initiative on Neuroscience and Law….
Q: Somewhere in your belief system do you hope that our consciousness continues after we die physically?
A: I’m not certain. By the way, I don’t have a belief system, I only have a possibility system! But I do hope that consciousness will survive our bodies.
Q: Would you really want to live forever ?
A: For better or worse we probably have no choice. Option one is we might just die and shut off like going to sleep. Possibility number two is there might be something much bigger than us, in which case we don’t have a choice about it anyway – we’ll just find ourselves there.
Q: What do you do when you’re not writing fiction?
A: During the day, what I try to figure out is how the brain works and specifically this issue of how the brain constructs reality. How do you put together hundreds of billions of cells and get it to have a private subjective experience? Consciousness. In other words, if I gave you a hundred billion Tinkertoys and asked you to put them together in a complicated fashion, the question is at what point would you add one more Tinkertoy and suddenly it is having a private subjective experience. It can experience the colour red and the feeling of pain or the taste of feta cheese. Not only do we not have a theory of that but we don’t even know what a theory of that would look like. That’s the situation we’re in in modern neuroscience. What we are doing is seeking any sort of inroad and I recognise that with synesthesia, where people have a mixture of the senses. Your neighbour’s reality can be very different than your reality. The same stimuli in the world can be inducing very different experiences internally and it’s probably based on a single change in a gene. What I am doing is pulling the gene forward and imaging and doing behavioural tests to understand what that difference is and how reality can be constructed so differently….
(Source: Sean O’Hagan, The Guardian; Image: The New York Times)