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

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Limits of brain neuronal spatial mapping

It is being claimed that brain maps the world space in (roughly) 1-to-1 correspondance of a place to a neuron (link1, link2). My question is: as the mapping happens in 1-to-1 manner, then is it ...
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1answer
230 views

How do neurons inverse an action potential?

See the following figure (source): The pathway on the right (SN $\rightarrow$ interneuron $\rightarrow$ F Neuron $ \rightarrow $ flexor muscle), is explained as follows: The action potential in ...
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1answer
155 views

Differences between synaptic connections

Consider the following synaptic connections (from here): axodendritic - A term pertaining to an excitatory or inhibitory synaptic connection between the presynaptic axon of a transmitting neuron ...
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2answers
1k views

How does an inhibitory synapse communicate to the cell body of a neuron?

I picture a neuron as having multiple trees of dendrites attached to the cell body with a single axon leaving the cell body. I believe the cell body near the axon root makes the decision to fire or ...
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36 views

Distribution of synaptic connections

What is the roughly the distribution of the various synaptic connections in the brain. Consider the following types: axoaxonic synapse between the axon of one neuron and the axon of another ...
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37 views

My eyes were accidentally exposed to high infrared radiation and they hurt, why? [closed]

My eyes were exposed to high amounts of infrared radiation. They hurt - why?
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1answer
52 views

Why to use transgenic mice in ALS models?

In ALS mice model with mutant SOD1 - there are use of transgenic mice, with insert of human mutant SOD1. Why is that? Why not to mutate directly mice SOD1 ? In transgenic mice, after few generations ...
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2answers
553 views

Does frequency of eye blinking reveal anything about human biology/nervous system?

I'm looking at an output of a single dry sensor EEG headband with the sensor positioned above left eye. As a side effect of it's placement, the device picks up eye blinks, and some eye motion as ...
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1answer
562 views

Why is the neuronal plasma membrane more permeable to potassium ions than sodium ions?

From what I understand, the greater permeability of the neuronal plasma membrane to K+ ions (which diffuse out) than Na+ ions (which diffuse in) helps to maintain the -60 mV resting membrane ...
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1answer
48 views

How the brain is affected by Alzheimer's disease

What exactly happens to the neurones in the brain? why can't they be repaired/restored? Why is it that there are so called 'good days'? What happens to the brain on such days?
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2answers
52 views

Nerve fiber responses to intense stimuli

Can one instantaneous, high-intensity stimulus performed on a nerve fiber generate a series of action potentials? Or are nerve fibers limited to one response action potential, no matter how intense ...
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2answers
392 views

Is warmth/temperature sensed linearly or on a different scale?

I understand that the atmospheric temperature is sensed relative to external body temperature. However, is the sensation of warmth registered linearly, or is it on a logarithmic scale, similar to ...
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2k views

Do we use 100% of our cerebral capacity?

I saw a movie yesterday called Lucy. In this movie, a girl called Lucy absorbs a large amount of CPH4, and her brain capacity slowly increases. So that brings me to my question which is : Do we ...
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1answer
80 views

Why does ALS start in middle age?

Amyotrophic lateral sclerosis (ALS) often starts at middle age, but I didn't find any suggestion why. Something seems to trigger the symptoms in middle age. If I am not mistaken, the sporadic ALS is ...
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26 views

Are there different types of communication and computation neurons?

I know from my basic education in neurology that the brain has various sorts of neurons. These are usually bunched into 3 different categories. I read in a recently published book including papers on ...
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1answer
109 views

Can a lack of sleep degrade balance?

For years, I've noticed that the day after a night of poor sleep (4 hours or less), my balance noticeably degrades. For instance, while walking 20 feet to the coffee maker, I might stumble into the ...
6
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4answers
296 views

Can children restore brain cells?

By "children" I mean young people at the age of 10 or lower. I know that the adult brain cannot restore brain cells, but what about children? I mean, the brain must develop from a few cells to a 90 ...
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1answer
210 views

Does antidromic conduction occur in the brain under normal conditions?

So I am reading a book on neuroscience and they mentioned in passing that the action potential is capable of travelling in either direction along the axon (orthodromic vs antidromic), The wikipedia ...
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1answer
390 views

Saltatory conduction of nerve impulses

I am aware about some basics of saltatory conduction of nerve impulses. I know that the nerve impulses (ion flow and the depolarization) are transferred from node to node in myelinated nerve fibers. ...
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2answers
2k views

How to make a fake auditory signal?

My question is about making fake auditory signals. The ear collects sounds from the environment, which are transformed into a neural signal by the hair cells in the inner ear. This signal is sent ...
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1answer
132 views

How well does it actually work to surgically reroute the optical nerve?

Two publications, Roe et al, 1992[1] and Metin & Frost, 1989[2], describe results pertaining to the ability of a region of cortex to process information from a different sensory mode than the one ...
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2answers
188 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 ...
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1answer
295 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" ...
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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 ...
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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?
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87 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.
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4answers
23k 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 ...
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1answer
42 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 ...
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1answer
14k 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 ...
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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 ...
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1answer
474 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 ...
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2answers
284 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 ...
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2answers
93 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 ...
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0answers
16 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?
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2answers
360 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 ...
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1answer
356 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?
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1answer
127 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 ...
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1answer
157 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 ...
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2answers
2k 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. ...
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2answers
563 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? ...
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1answer
469 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 ...
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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 ...
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1answer
216 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 ...
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2answers
214 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
84 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
57 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 ...
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1answer
9k 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 ...
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1answer
101 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
272 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 ...
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1answer
1k 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 ...