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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What are known methods of non-surgically disabling neural tracts/pathways (esp. Corpus Callosum)?

I think I've read something about usage of TTX and optogenetics, but I cannot find the papers for either anymore. Any reference would be much appreciated, especially those concerning mice and the ...
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220 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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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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108 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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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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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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45 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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Is there a lower temperature limit, below which we cannot sense a difference in temperature?

At work I have to handle samples stored at -20 and -70 degrees Celsius, and they don't feel that different to me.
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73 views

What is the role of the tissue surrounding neurons in decision making and taking control of impulses?

How does the fatty tissue surrounding neurons supports and enhances the speed of electrical impulses? How does it stabilize connections that take control of impulses and decision-making? The cells ...
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43 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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125 views

How are reflexes suppressed?

What neurophysiological process keeps reflex arcs in check? For example, the withdrawal reflex causes the hand to jerk back when the fingers touch something painfully hot incidentally. However, that ...
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107 views

Depolarization and hyperpolarization in stereocilia of the inner ear

It’s a well mentioned fact that when the stereocilia of the cochlear hair cells bend in one direction, the hair cell depolarizes, and when the stereocilia bend in the other direction, the cell ...
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212 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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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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21 views

Typical neuronal firing rates across the human cerebral cortex

I would like to find a scientific article (or articles), which would summarize typical neuronal firing rates in different parts of the human cerebral cortex. Any good references on this?
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27 views

Does the number of nodes determines the rate at which a neural signal is transmitted?

I know that the the bigger the neuron's diameter is, the faster the neuron signal is transmitted. This makes sense according to the proportionality of resistance to the inverse of area and thus, in ...
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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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173 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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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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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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52 views

Is there a way to know how many sodium channels are active (conducting) at a given time in the brain?

I was doing some reading about anti-epileptic sodium channel blockers, then wondered how many sodium channels are actually conducting (actively passing ions) at any given time, that is, in an ...
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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" ...
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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.
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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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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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161 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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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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348 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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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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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? ...
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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. ...
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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 ...
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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 ...
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158 views

Can axons act as receptors?

In all histology books, it is stated that all sensory nerve endings (receptors) consist of dendrites that translate physical stimuli from the environment into neural signals. However, several sensory ...
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92 views

Biological implementation of convolutional neural networks

In computer science, 'convolutional neural networks' are used, that are meant to be inspired by biological network structures like found in the human brain visual cortex. In the computer ...
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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? ...
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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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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 ...
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368 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?
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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 ...
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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 ...
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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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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 ...
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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 ...
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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
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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 ...
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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 ...
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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 ...
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808 views

Lumosity.com? Is it based on science?

I always see these Lumosity adds on TV, and I personally feel they are just trying to "sell me something". I did some layman's research(wikipedia) and read that "Studies of Lumosity's effectiveness ...