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39

The brain is indeed stacked with blood vessels, as shown in a 3D model in Fig. 1. Fig. 1. 3D-printed model of blood vaculature. Source: Biobots. The blood supply on the surface of a live brain is readily seen during a craniotomy (Fig. 2.) Fig. 2. Surface of the brain. Source: The Sterile Eye. When freshly prepared, the interior of the brain appears ...


16

No, it can't be done for a lot of reasons. Here are just a few. 1) Memories are stored in electrical pathways, not the the cells themselves. You don't have 1000 memories in a chunk of brain that contains 1000 neurons. If you don't get the entire pathway, you won't get the memory. 2) Once a nerve is cut, it won't fuse with another cut nerve. All you'll have ...


11

Is there a significant difference in calorie burn? No. The brain, while only making up 2% of our body weight, accounts for ~20% of our energy use at rest. That's because the brain, being critical for survival, is a very high-maintenance organ. At rest, the membrane potentials of all neurons - firing or at "rest" - need to be controlled/maintained. Of ...


10

First of all, I would like to point out that making analogy between digital computers and the brain is often very misleading. That being said, my answer is, some scientists believe so, some don't. Several things to consider: Some neural systems are not spiking. C. elegans for example has a nervous system that is entirely analogue. Human nervous system ...


9

http://en.wikipedia.org/wiki/Electromagnetic_pulse mentions the following natural sources of EMP, which I have ordered by frequency / period, from the shortest to the longest: Electrostatic discharge from objects coming into contact (normally too small to be of any concern) Lightning (milliseconds) Solar flares (hours.) Such flares cause geomagnetic storms ...


9

Short answer The exact mechanism behind tinnitus (ringing in the ear) is unknown. Background Of the two theories you pose here, to the best of my knowledge the second one is the most widely accepted. It is a generally accepted phenomenon that whenever neural systems are being deprived of input, they start seeking new input, or even generate it ...


8

There's a very big difference between doing the calculations needed to simulate the human brain (or any animal brain FTM - we can do a fairly decent job on C. elegans.), and doing computations. While a basic leaky integrate & fire model is fairly simple, to ACCURATELY simulate a single neuron in real time takes a pretty fast computer. See e.g. these ...


7

The brain is not an electronic device. An EMP is basically a large amount of electrons flying by all at once. They are negatively charged, and as they pass by they distort your local EM-field (hence the name). This distortion induces current in the wires (a phenomenon known since Faraday) - since most wires aren't made with a large tolerance, the sudden ...


6

If firing rate is from 1 Hz to 200 Hz, 100 trillion to 20 quadrillion synaptic firings. Neuronal (say, measured from soma) firings will add up to 86 billion to 17.2 trillion action potentials per second. It important to remember, that synaptic firings "sum up" in soma or interfere between each other, so the are more of those. Read more: ...


5

While action potentials are usually binary, you should note that synaptic communication between neurons is generally not binary. Most synapses work by neurotransmittors, and this is a chemically mediated graded response that, for example, act on voltage-gated ion channels. So even though action potentials are often binary, communication between neurons are ...


5

Is there a visual demonstration I can see of approximately how "packed full of cells" the brain actually is? Yes. You can inject tracers in the CSF (Cerebrospinal fluid) or in the ventricles and monitor them. In this study, the authors have injected a fluorescent tracer in the CSF and used a direct imaging. We used in vivo two-photon imaging to ...


5

The "wiring" of the brain is more important than the actual size. If only size would matter that basically humans would be rather unintelligent beings ( many many animals have larger head and brain than us). Intelligence is more related to the complexity of the brain (number and size of different brain components) and the number of connections between ...


5

I did a quick search and found some research in this area. Sleep inertia is the technical term for feeling groggy for a while after waking up. In a review article by Patricia Tassi, Alain Muzet (Sleep inertia. Sleep Medicine Reviews. Volume 4, Issue 4, August 2000, Pages 341–353), they define sleep inertia as Sleep inertia is a transitional state of ...


5

Feelings of pleasure and reward are transient in nature. Similarly, the dopamine release in the reward centers (the limbic structures) is transient, namely in the order of seconds (Rebec et al., 1997). One way to chronically elevate dopamine levels is by administering certain drugs. A notable/notorious example is methamphetamine, which elevates mood and ...


4

This isn't a ridiculous idea; Transcranial Magnetic Stimulation is used in research and even has some use as treatment for depression (http://www.mayoclinic.org/tests-procedures/transcranial-magnetic-stimulation/basics/definition/prc-20020555) In TMS a strong, localized magnetic field can disrupt normal functioning of regions of the brain. For instance it ...


4

The brain activity is electric and chemical. The male adult human brain contains about 86 billion neurons (Azevedo et al). There is about 100 trillion connections between them. Solving a puzzle like that is not easy.. what sort of breakthroughs would be necessary to intercept these signals and interpret them as exact thoughts? What you are referring to ...


4

Human body is a glucose driven machine which intake carbohydrates and converts to glucose. Energy is yielded from the glucose and glucose is stored as glycogen. When the carbohydrate intake is somehow reduced then body will shift its mechanism and uses the fatty acids to produce energy. Liver synthesis ketones from fatty acids in our diet or from body fat. ...


4

Levo-Dopa is used as a first-line treatment of Parkinson's disease. Unlike dopamine, L-Dopa is able to cross the blood-brain barrier. There it is converted into dopamine. To prevent premature breakdown in the gastro-intestinal and circulatory system after oral intake, carbidopa can be co-administered. Also MAO-B inhibitors and COMT inhibitors can be applied ...


3

I think this website provides a pretty surprisingly thorough breakdown of avian brain anatomy, including historical contexts and debate around what exactly is homologous and what is not, and whether 'homologous' is a useful bit of information. In short: It was thought until recently that the bird brain was just the core of the mammal brain with some layers ...


3

Damage to the brainstem - the part of the brain responsible for controlling breathing and the heart - has different effects on the heart and the lungs. Every heartbeat is not directed by the brain. Instead, the brain has a "throttle" to the heart, by which it can regulate the heart rate up and down, but the actual heartbeat is initiated by special cells in ...


3

The answer to this question is complicated, but assume it's not for the moment. The easy answer is that our eyes can detect patterns we're familiar with and "produce" an answer in the form of a number. Unfamiliar patterns do not produce this 'number'. Take a die. We are immediately aware of the number of dots in the typical arrangement of one to six. We ...


3

In general I'd say "left and right brained behaviour" is total nonsense. I guess the origin of this kind of claim is a bad press release or something. Let's start with something simple. Say hearing. When you hear a sound to your left ear, it is projected strongly to the contra-lateral side (right hemisphere), and weakly to the ipsi-lateral (left hemisphere) ...


3

T-cell migration to the brain is very limited and occurs at a very low level in healthy conditions, however during diseases the number of T cells passing through the blood-brain barrier is elevate due to increased expression of traffic signals and adhesive molecules. I've found two good articles on how T-cells migrate through blood-brain barrier: J Neural ...


3

Your question is basically a matter of defining brain plasticity or more broader, neuroplasticity. According to a well-cited paper in Brain (Cramer et al., 2011) neuroplasticity is defined as: [...] the ability of the nervous system to respond to intrinsic or extrinsic stimuli by reorganizing its structure, function and connections. Hence, the term can ...


3

Mordake was a conjoined twin fused at the head (Fig. 1). Twins conjoined at the heads are rare, occurring only once in every 2.5 million live births. Moreover, in Mordake's case it was a parasitic twin head with an undeveloped body that was fused with his own head. This condition is referred to as craniopagus parasiticus, or épicome / epicomus. Craniopagus ...


3

I think that the type of fMRI you are referring to is blood-oxygenation-level-dependent fMRI or BOLD fMRI. The principle behind MRI in general is the detection of proton signals from water molecules. The proton signal is generated by magnetizing the protons in tissue, which causes their spin to change. A subsequent powerful radio wave disrupts this spin ...


3

The mind is an abstraction which arises from physical and chemical processes within the brain. For a crude analogy, think of the brain as an incredibly complex, self-modifying, multithreaded program. The mind would then be the abstraction arising from the behavior of the program as it runs. Consciousness would be the abstraction arising from the behavior ...


3

Answering the question what is needed for a human brain to evolve starting from a cephalopod brain is hard. However, I can expand on what is thought to have been the driving forces behind the evolution of the humanoid brain (Hawks, 2013): The species of the famous Lucy fossil, Australopithecus afarensis (~3-4 mln yrs ago), had skulls with internal volumes ...


3

Short answer External stimuli can drive autonomic responses. Background The autonomic nervous system is a visceral sensory and motor system. The viscera are the internal organs. Virtually all visceral reflexes are mediated by local circuits in the brain stem or spinal cord (Fig. 1). It is one of two major subdivisions of the nervous system; the other being ...


3

The phenomenon in question is probably related to people with uncorrected/undercorrected myopia. This "ancient" phenomenon is called stenopeic slit effect (a case of pinhole effect): when the person squints the visual acuity becomes better because of smaller blur circles: the "slit" between the eyelids is the key point improving blurring. One can check if ...



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