The study of the structure and function of the nervous system and its components.

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4answers
674 views

Can the human brain be reduced to a binary system?

Does the brain really function like a computer as in, ultimately every response is related to a binary sequence based on whether particular neurons fire or not?
6
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2answers
138 views

Are there nerves in the umbilical cord?

I have always imagined that cutting the umbilical cord after birth might be painful. But I have always been confused about who would feel the pain and why. It occurred to me that the mother or the ...
6
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1answer
229 views

How does a neuron change as you learn?

I am currently taking a course called "Introduction to Machine Learning with ENCOG 3", and I have a question about how well the Artificial Intelligence (AI) algorithm for a "neural network" ...
46
votes
5answers
2k views

Human perception of time depending on age

From what I can tell and what thus far all people with whom I discussed this subject confirmed is that time appears to "accelerate" as we age. Digging a little, most explanations I found basically ...
12
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1answer
2k views

How does this illusion work?

I found this image on Google+ If you shake your head you can see a portrait of a person. Can anyone explain how the image is constructed in the brain?
2
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0answers
69 views

How does an increased amplitude affect nerve conduction velocity?

My professor said that increasing the amplitude (the amount of depolarization e.g. depolarizing from -80 mV instead of -50 mV) leads to a greater conduction velocity.
27
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4answers
21k views

How does cerebrospinal fluid circulate in the central nervous system?

Cerebrospinal fluid (CSF) is produced in the choroid plexus of the lateral ventricles and in the 4th ventricle of the brain. CSF then circulates through the ventricles of the brain and the ...
3
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1answer
196 views

What keeps the resting potential of neurons constant at -70 mV?

I know the sodium-potassium pump pumps out 3 Na+ ions and pumps in 2 K+ ions per reaction so the negative charge in the axon increases. However, once the voltage (difference of charge inside and ...
2
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1answer
39 views

Are there emotions that motivate pattern completion? If so, where in the brain are they located?

I have been studying musical "tension." Musical tension essentially refers to the "expectations" one builds up in a melody that are then "released" when a stimulus matching the expectation occurs. For ...
0
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1answer
13k views

How reversible is decerebrate posturing caused by brain stem damage?

This is a follow-up question to How likely would Abraham Lincoln be to survive his wounds today? You don't have to see a CT scan or autopsy to know if the brainstem is injured (directly or ...
4
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2answers
3k views

Do neurons secrete multiple neurotransmitters, or just one type?

I know that neurons communicate between each other by filling the junction between dendrites with neurotransmitters. What interests me is if a single neuron only works with one type of ...
7
votes
1answer
391 views

What causes Paresthesia (Pins and Needles) at a cellular level?

I've looked it up in plenty of places like the Wikipedia page and such, and it is clear that the most common cause of Paresthesia is either a fair amount of pressure on a specific patch of skin ...
1
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2answers
159 views

What were the symptoms of Phineas Gage after suffering his brain injury?

Phineas Gage was a construction worker who suffered a head injury due to an explosion at a construction site. A metal rod was pushed up his cheek and through his head. I have heard he demonstrated ...
1
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2answers
84 views

How do neurons receive the ions needed for creating electrical pulses?

I really wonder how ions are transported into the brain and the neurons for creating electrical potentials - how do ions get from our digestive system to the neurons? Or are the ions just freely ...
0
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0answers
13 views

Why is dopamine considered both an excitatory and Inhibitory neurotransmitter? [duplicate]

To me it seems the one allows flow and the other prevents flow. How does dopamine do both?
3
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2answers
347 views

Can dietary monosodium glutamate intake induce restlestness?

The question is all in the title. More context: I like phở soup. I have noticed that I get restless after eating the phở soup at some restaurants. The effects are similar to the ones resulting from ...
2
votes
1answer
327 views

What is the biochemical reason for mental fatigue?

Is it known exactly why the brain needs sleep? What's dropping low / going high when we experience mental fatigue? I can see why low glucose could result in mental fatigue, are other reasons known?
4
votes
1answer
124 views

How small does a nanobot have to be to “swim through the brain” and access any neuron it wants to?

I read on this question What is in the space between neurons in a brain? that there is actually not much empty space in a brain. But my question is slightly different. Is there a visual demonstration ...
5
votes
1answer
110 views

Case study and speculations on the brain of Edward Mordake

I am very interested in the case of the man named Edward Mordake who lived in the 19th century. In particular, he had two faces. If you have not heard of this man, please, search this up as there are ...
9
votes
2answers
1k views

Why are potassium channels slower than sodium channels?

I am relatively new in the subject of biology. I have a strong mathematical background and in order to get into the field of computational neuroscience, I am trying to get some biological background. ...
4
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2answers
523 views

Why can humans feel electricity?

What evolutionary process has provided humans with the ability of feeling electric current? Besides lightning and electric eel, what natural hazards include electricity that poses a threat to humans? ...
6
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1answer
297 views

Is the six-layer cortex model of the mammalian cortex still the most accepted model?

I've been reading a bit about the different layers of the cerebral cortex and its clear that certainly not every region of the cortex has the same number of layers. Thus, the idea that every region ...
3
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1answer
58 views

Neuroscience behind the crash

After experiencing things like stress, intense exercise, or using drugs such as caffeine and amphetamine, subjects often assume a depressive and lethargic state afterwards, known as a "crash." What is ...
7
votes
2answers
180 views

Why does the human brain not overfit when training at some task?

One of the problems that occur during (artificial) neural network training is called overfitting. The error on the training set is driven to a very small value, but when new data is presented to ...
8
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1answer
199 views

What is the mechanism behind tinnitus?

I seem to have come across two contrasting explanations for tinnitus induced by loud noises- i.e. damage to the hair cells in the cochlea. On the one hand, I have read that damage to the hair cells ...
6
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2answers
146 views

What is the latency between paired neuronal responses in the brain?

Is there any data on how long it takes for signals to propagate from one neuron to its neighbors in complex networks, such as the brain (particularly the neo-cortex)? If not, is there any reasonable ...
3
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1answer
67 views

If nerve consists of many axons, where are then their soma located?

This question has haunted me for two years. Wikipedia mentions : A nerve is an enclosed, cable-like bundle of axons (the long, slender projections of neurons) in the peripheral nervous system. ...
3
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1answer
56 views

Does tremor frequency generally increase as Parkinson's disease progresses?

I've been trying to research this question, but most if not all the on-line journals require costly subscription, and the studies that are posted look at tremor frequency with regards to other ...
5
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1answer
381 views

Relationship between nerves and axons

I just wanted to get a realistic viewpoint of our nervous system. I understand arteries and veins, but I wanted to know how similar our nervous system is to that? I understand we have neurons ...
24
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1answer
8k views

What do you see when your eyes are closed?

If you are in pitch black and you close your eyes, you sometimes can see strange shapes of various colors. A lot of the time these shapes and colors change as you observe them. This phenomenon still ...
5
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1answer
92 views

Are there any known health benefits / risks from milliampere current (0.1-2 mA) on forehead?

This is about devices like that sold by foc.us that allows user to apply a small current on a specific part of the forehead. For the sake of this question I use the foc.us "gamer" model as example. ...
2
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1answer
246 views

Have webs woven by LSD-intoxicated spiders ever been studied for their efficiency in fly catching?

I ask, because I have a different interpretation of the experiments performed on web-weaving spiders. The famous Robert Pirsig maintains that LSD is somehow helpful to web-weaving spiders, because it ...
3
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2answers
85 views

Is numbness the absence of one or all touch sensations?

I am studying the effects of tetrodotoxin and its symptoms when consumed. Numbness is one of the first sensations reported. But I googled numbness and I couldn't find information about whether this ...
9
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1answer
938 views

Why do antidepressants have a delayed onset of action?

Why do antidepressants take so long to reach efficacy? I've read of theories about it perhaps being due to the strength of negative feedback via serotonergic and adrenergic autoreceptors during the ...
2
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2answers
77 views

What would happen if brain neurons did not reduce their sensitivity to neurotransmitters after prolonged exposure?

From my understanding, neurons decrease their sensitivity to neurotransmitters by reducing the amount of receptors on the cell membrane in response to sustained neurotransmitter activity. One ...
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2answers
3k views

What is the difference between a graded potential and an action potential?

I was under the impression the only signals neurons send using changes in membrane potential are action potentials. But my biology professor showed us diagrams of graded potentials and action ...
8
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1answer
179 views

Can we change our dopamine baseline levels?

Can we change our dopamine baseline levels? High dopamine levels improve alertness, problem solving, but may also cause anxiety and aggression. I've read that smiling and laughing, eating certain ...
0
votes
1answer
141 views

Can plants feel pain? [closed]

I was wondering whether plants could feel pain, for example, does grass feel pain when you mow the lawn? Or do the plants and trees that grow vegetables and fruits feel pain when you harvest them? ...
4
votes
1answer
367 views

What determines whether an action potential is inhibitory or excitatory?

What determines whether an action potential is inhibitory or excitatory? Is it determined by the receptors, the neurotransmitters, or some other mechanism?
4
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1answer
990 views

Is there a relationship between Melatonin, Norepinephrine and depression in humans?

I'm reading a booklet on melatonin published in 1996, titled "Melatonin and the Biological Clock". This particular paragraph caught my attention and I would like to better understand what it means: ...
4
votes
2answers
18k views

What are the functions and differences between axons and dendrites?

My textbook doesn't do a very good job of pointing out what the differences between the two are. It basically mentions axons only in the same breath as the synapse (that synapses are the endings/tips ...
5
votes
1answer
74 views

Is transplantation of neurons between species possible?

Can brain tissue from one species be implanted into the brain of another species? Because the brain is tolerant to the introduction of antigens (it is said to be immuno-privileged), I was wondering ...
4
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2answers
288 views

Does learning increase the number of neurons in the brain?

I am attempting to understand neurogenesis related to learning. Does learning increase the number of neurons in the human brain? What would be some good scientific publications to read?
2
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1answer
53 views

Can we change the direction of a neurological signal? [closed]

My question is can we change the direction of a neurological signal? When a neurological signal is generated it goes to the brain. Along the way it passes synapses. Can we make it change it's pathway ...
4
votes
2answers
96 views

Why do negative ions flow into a cell in an inhibitory synapse, even though a neuron has a negative resting potential?

In my spare time I have been reading an introductory Psychology textbook and this question came to my mind after reading about action potentials. I have no previous knowledge in chemistry so if I do ...
7
votes
2answers
99 views

What features cause mechano sensory adaptation?

In relation to mechanoreceptors (e.g. pacinian corpuscles), what stops a constant stimulus from producing action potentials? I understand that adaption is used to filter out stimuli that aren't ...
2
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1answer
48 views

Hodgin-Huxley model for a single neuron - continuation

As continuation to This question I have posted. Another set of questions is given for the same model : This time it is also given that for $t<0$ the membrane potential is $u_0$, and at $t=0$ it ...
3
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1answer
69 views

Hodgin-Huxley model for a single neuron

I am viewing (through edX ) an introduction course to computational neuroscience. In the second lecture, the Hodgin-Huxley model is considered. I am going over some of the questions and have ...
5
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2answers
2k views

How is membrane capacitance related to the increased speed of saltatory conduction?

Here is the original question which inspired my question. As explained by the answers there, the reason saltatory conduction in myelinated neurons is faster than non-myelinated conduction is because ...
3
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1answer
68 views

What determines the pathway of a neurological signal?

My question is about the neurological signals. In our body when a signal, for example a hearing signal from hair cells, is built, it goes through a lot of neurons and it passes a lot of synapses. I am ...