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

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If a dead snake reflexively attacks itself, why does it not always attack itself?

Recently there has been this video going around of a snake that had been decapitated. Its body swung around to the decapitated head and the head attacked the body on "reflex". Now we know that most ...
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68 views

on/off behavior of neural networks

What causes a group of disembodied neurons in a dish to fire after a silence? If there are no neurons providing a stimulus for more firing (as in a dish of disembodied rat neurons), then why don't ...
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64 views

Are there baby drinks closer to breast-milk?

Many women cannot or will not feed their children with breast-milk. It is my understanding breast-milk has many advantages over formula. Some psychological like oxytocin and some physiological like ...
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68 views

Somatosensory System

I have a test in my upcoming Neuroscience class, one of the items on the study guide is: Identify 2 means by which a maintained, constant stimulus produces only a transient excitation of the ...
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127 views

What evidence gives clues to the physiological basis for conversion disorder?

Conversion disorder has a set of DSM diagnosis criteria, which, among other things, includes ruling out all neurological disease. However, as the media has shown us (and one could argue a biased ...
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81 views

Can the negative afterimage appear only if there is light or is it possible in darkness?

Reading the following paragraph: After staring at the red and blue shamrock, you saw a green and yellow afterimage. Opponent-process theory proposes that as you stared at the red and blue ...
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87 views

What is the current consensus, if any, about why long term potentiation is not clearly correlated with learning?

I was watching a video where a professor said that according to some experiments, Long Term Potentiation (LTP) is correlated with better learning, while in yet other experiments, LTP is correlated ...
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53 views

What were the first neural systems like?

I'm curious about the origin of the neural network. I'm thinking perhaps once life evolved beyond the single cell organism, it needed a simple neural network to coordinate those cells, and cell ...
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209 views

Are these claims of “revolutionising” understanding of human vision and hearing valid?

I've started a hobby machine vision project (and posted some questions to this end on other SE sites) and on a side track, also been looking at relevant research in human vision (and partly, hearing). ...
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163 views

Are all action potentials the same shape and amplitude when graphed with respect to time?

The most common visualization of an action potential is a graph of the difference in membrane potential (y axis) at a particular time (x axis). According to my textbook Cognitive Psychology by E. ...
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175 views

Can the human eye distinguish colors in the periphery?

In the back of my mind I have the idea that human eyes can't notice the color of objects in the far periphery, and that any subjective perception of colors is done by the brain that tries to fill in ...
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909 views

Under what circumstances will a human neuron divide?

I read somewhere that a mature neuron loses its ability to divide, except for very specific situations. I was unable to find the description of those situations. What are they? (I'm sorry I'm not ...
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101 views

What are the total number of action potentials in the human brain?

Is there an approximate figure of the total number of action potentials in the human brain? It's my understanding that there are ~ 60 billion neurons in the brain with ~ 100 trillion connections ...
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212 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 ...
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67 views

What happens when someone is stung by a jellyfish?

What happens in the human body when someone is stung by a jellyfish; namely a box jelly. Judging by what I have heard about the stings I'm guessing that they involve a neurotoxin. But what is ...
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63 views

How to measure trajectory regularity?

I have two animal running trajectories. A regular one with repeated back and forth running between point A and B, like the one on top in the figure. The other one is very irregular, animal paused and ...
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88 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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56 views

Relationship between toxicity of drugs and negative effects on brain

Are psychoactive drugs with lower lethal doses more neurotoxic (more damaging to the brain)? For example, tetrahydrocannabinol (one of the active components of cannabis) has a much higher lethal dose ...
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428 views

Do effects of caffeine on human body change with habitual use?

I've been reading about homeostatic nature of a lot of neurobiological processes - the brain is trying to maintain a balance by desensitizing receptors, re-uptaking and breaking down ...
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88 views

Bugs' love for light

Do bugs love light bulbs because they resemble the stars or is it the sun? How do they sense the bulb? What is the purpose of this "brightophilia" that has evolved in insects?
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98 views

Why can action potentials not be initiated at dendrites?

Why are action potentials not initiated at dendrites, although dendrites are the first to receive input from the presynaptic cell? In fact, excitatory postsynaptic potentials (EPSPs) at the dendrites ...
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63 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. ...
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112 views

Mechanisms of extracellular stimulation of neurons

When stimulating a group of neurons with an electrode, let's say we put it in a region that contains axons, what is the mechanism by which the axons are stimulated? I've been told electrodes ...
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935 views

How long does a signal from the brain take to reach the limbs?

If the brain sends a signal to move what's the time it takes the signal to travel via neurons to motor neurons in hands, arms and legs? How fast do those signals travel?
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142 views

What is the biological principle of this “holotropic breathwork” technique?

Holotropic breathwork is a non-drug technique developed by Stanislav Grof used in psychotherapy. The therapy as a whole is usually called holotropic breathwork (at least by Grof himself) and will most ...
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70 views

Can neurotransmitter depletion cause short-term drug tolerance?

I'm curious to know if neurotransmitter degradation factors into drug tolerance and neural conduction and, if so, to what extent. As I recall from textbooks I read as an undergrad, one mechanism of ...
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180 views

What is the difference between different brain regions

The brain is separated into different regions, and different regions perform different tasks. Well, what are the differences between these regions on the cellular/systemic level. The brain is made up ...
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184 views

Zombie Ant Fungus?

Ophiocordyceps unilateralis is a parasitoidal fungus that alters the behavior of the infected. Source: Wiki page. How is the fungus able to alter the behavior of the infected to such specfic ...
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900 views

Why is Botulinum toxin the most potent poison known?

Botulinum toxin (trade name Botox) inhibits acetylcholine release in neurons and causes botulism, an acute paralytic disease which leads to nerve degeneration and takes a long time to recover. I've ...
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100 views

Are CN3, CN7, CN9 and CN10 the only Parasymphatetic Cranial Nerves?

It has been my thought for a long time that that is the case but I am unsure about it now, since the parasympathetic tract of colon sigmoideum does not seem to have connection with CN 10. It connects ...
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43 views

Is the autonomic nervous system only activated by internal stimuli?

My professor claims that the autonomic nervous system is only activated by stimuli from organs but I really feel like I've read that it can be activated by outside stimuli, although I'm not sure what ...
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55 views

Oxygenated hemoglobin in MRI

I have read the following sentence: Because this oxygenated hemoglobin is unaffected by magnetic fields, the response RF signal returned to the fMRI scanner is stronger when there is more ...
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81 views

How pain can stimulate the vagus nerve

I'm trying to find out why a prompt, severe, short pain is causing a stimulation of the vagus nerve. What could the physiological explanation be? Is that because the pain is triggering the ...
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63 views

What (open) software there are for simulating behaviour of human (cortical) neurons?

Is there any reliable open-source software for simulating the behaviour of human cortical neurons? I am looking for serious software, so let's assume I have access to a computer with more than 10,000 ...
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2k views

What are the advantages and disadvantages of being ambidextrous?

What are the advantages and disadvantages of being ambidextrous? We have two hands and we nearly can't use one and this seems like a weakness, and a stupid one when you first think about it. But ...
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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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124 views

What kinds of arousal can a human brain experience?

I've been reading about the new phenomenon called "arousal addiction". The context in which this term is used is Internet, Porn and/or video game addiction(cummulatively Internet Addiction Disorder - ...
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1answer
167 views

Is there a way for a 19th century scientist to prove that the octopus doesn't revive?

Say a sophiscated scientist in the 19th century noted that applying soy sauce on a dead octopus leads to movement of the legs, as a result of the voltage differences resulting from the salt in the soy ...
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141 views

Epilepsy explained by computational neuroscience

A few years ago, on my maths masters, I did a module in theoretical neuroscience. I was shown that the mathematical framework the course developed for neurons, with a small adjustment in the ...
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87 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?
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67 views

Mechanism behind negative conductance of ion channels

I am struggling to understand negative conductance shown on I-V curves on ion channels. Mechanistically, negative conductance means that inward (or outward) current increases when voltage across ...
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60 views

Do local field potentials (LFP) create waves on the surfaces of nerve cells?

Are waves created by the LFP on the surfaces of neurons cell bodies? Since the cells have a resting potential, do these waves create harmonic oscillation of the membranes at particular frequencies? ...
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91 views

The mechanism of mechanoreception?

I am interested in knowing the molecular mechanism behind mechanoreception/mechanotransduction (i.e. mechanism behind receptor potential generation on mechanical stimulation). I know that most ...
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285 views

Are there any types of cancer that cause neurons to divide?

After birth neurons generally do not divide. But is there any specific type of rare cancer or tumour where neurons divide? And if there is such a cancer, then how is it possible for a neuron to regain ...
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45 views

What are the molecular mechanisms that make the turtle brain more resistant to hypoxia?

I know that turtle brains, particularly those of individual species that hibernate and burrow are particularly resilient to hypoxia and any tissue damage secondary to a hypoxic event. What are the ...
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48 views

Is there a type of amnesia that seperately affects long-term memory?

Is there a medical condition that affects the long term memory, but leaving the short-term and working memories totally or fairly intact?
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939 views

Why Do Nerve Signals Get Crossed?

First off, I don't know if this is a normal healthy thing to occur. There have been many times where I have an itch on say my arm and I scratch it, only to feel the scratching elsewhere on my body. I ...
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217 views

Is it technically possible to make someone see something when their eyes are closed?

I'm writing a little article and need any information about how human vision works and latest technologies and discoveries around. Actually its not a professional article. Its for a group of my ...
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1answer
119 views

Why do we yawn?

I've read a new study which suggests that yawning may help you keep a cool head. Also, the findings might hold some hope for sufferers of insomnia, migraines, and even epilepsy. Is there any ...
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495 views

How does the eugeroic modafinil work?

How does the drug, modafinil (Provigil), exert its eugeroic (wakefulness-promoting) effects? I've read that it works by increasing dopamine and histamine concentrations in the CNS and by serving as a ...