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

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Dark veil when getting up too fast

I was asking myself this weird question. When you get up or stand up too fast, sometimes, you see something like a dark veil, and you aren't able to see anything distinctly for 2 or 3 seconds, then ...
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154 views

How does an axon “know” it's not connecting to its own neuron?

I recently read about an experiment where they removed the dendrites and axons from rat neurons and placed them on a grid. After a while they started reconnecting and were able to learn things. Since ...
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Can one dendrite pass through another?

While tracing dendrites on EyeWire I encountered the following situation. They belong to an Orientation Selective Ganglion Cell. It's the first dendrite I've noticed with such a clear 'hole' in it, ...
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96 views

Soma-soma paired neurons

I'm reading this paper for a presentation I have to do. Since I have no real biology background I encountered a few questions and one I couldn't find an answer using my google-fu. It's about how ...
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185 views

Why is the Patellar reflex not triggered when the tendon is extended slowly?

I have been previously told that the Patellar reflex (knee-jerk-reaction) exists to prevent the hyper-extension of the patellar tendon. Yet if the impact to the tendon is delivered slowly - i.e. by ...
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951 views

Is it possible for any animals today to have more than one brain?

Is it possible for any organisms in the animal kingdom to have more than one brain?
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Which brain regions are D1 dopamine receptors expressed, and which brain regions are D2 dopamine receptors expressed?

This is a follow-up question to If D1 receptors stimulate adenylate cyclase (through GPCRs) and D2 receptors inhibit it, then why do mutations in both have similar effects?. As a further question - ...
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173 views

Are cerebellar basket and stellate neurons actually different cell types?

The title more or less says it all, but to contextualise a bit: Cerebellar molecular layer interneurons have been classified, probably since Cajal, into the basket cells, which synapse onto the soma ...
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120 views

Pharmacologically, can tricyclic antidepressants have a side-effect profile similar to neuroleptics?

Torticollis (wryneck, cervical dystonia) is a neurologic movement disorder causing involuntary muscle spasms in the neck. Often, neuroleptics can cause such a side effect. I'm wondering if this ...
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63 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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786 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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139 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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567 views

Is there a biological basis to physical attraction?

Is there something encoded within us that makes us attracted to, e.g., someone taller or shorter with blonde or brunette hair with green or blue eyes? Or, is this phenomenon completely based on ...
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46 views

Neuronal Architecture of the Brain

To what extent do brains (e.g. of humans) contain recurrent connections? I am studying artificial neuronal networks and frequently encountered the statement, that recurrent neural networks are ...
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2k views

Why do neurons die so fast without oxygen and nutrients?

Some human tissue can survive without oxygen a couple of minutes, even hours. Why are the neurons are so "weak" and depends so much on oxygen and other nutrients and cannot live without them for ...
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363 views

Is it purely the nervous system causing vaginal lubrication (arousal)?

My girlfriend was watching some documentary on TLC about a paralyzed woman getting pregnant. I believe that woman still has some feeling, as she spoke about feeling the effects of a bladder ...
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455 views

Cat purring: What are some possible underlying mechanisms behind purring and bone remodeling and formation?

http://www.scientificamerican.com/article.cfm?id=why-do-cats-purr The article above says that cats purr mostly when they're wounded or under duress. They hypothesis that cats purring leads to ...
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838 views

Density of neurons/cells in the mouse brain

Could someone point out some relevant papers or resources (an online DB maybe?) describing the density of neurons (or, more in general, of cells) in different areas of the mouse brain?
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Task-dependent “reversed” handedness: why use left hand for some tasks? How is it controlled by the brain?

I am right-handed. Which means that when I hammer down a nail, I hold the nail in my left hand, with which I can hold it straight and at a controlled position. This is true in situations where the ...
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171 views

Understanding Membrane / Resting Potential from the perspective of ions?

From wikipedia article RESTING potential: "there is no actual measurable charge excess in either side. That occurs because the effect of charge on electrochemical potential is hugely greater than ...
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189 views

Brain + ethanol experiment suggestions needed

I need to demonstrate the effects of ethanol on a human brain (or other brain with developed telencephalon) in vitro; ideally the effects on vigilance and/or memory. Could you please suggest such an ...
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253 views

First discovery of long-term depression?

LTP was first described by Tim Bliss and Terje Lømo in their paper Long-lasting potentiation of synaptic transmission in the dentate area of the anaesthetized rabbit following stimulation of the ...
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115 views

Latency to audition in human beings?

On average, in a human being with no neurological deficits, how long does it take for a sound which is sensed in the ear to reach the cortex? Which brainstem structures are most responsible for the ...
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119 views

Why does getting certain chemicals in cuts hurt?

More specifically, shampoo. What are the mechanics of detecting a noxious chemical stimulus in terms of which receptors recognise what, how do they do it, and how is this information relayed to the ...
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Refractory period in action potential

I know that the part E in this graph is definitely the part of refractory period. My question : Will there be any effect on B,C or D if a stimulus is given at time B,CorD respectively ?
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107 views

Do adjacent axons in a nerve influence each other?

Suppose I have a nerve fiber consisting of several axons all running in parallel to each other. When an action potential is generated in a certain axon, this will alter the concentration of sodium ...
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114 views

How are synaptic vesicles brought to the synapse?

I'm reading about how synaptobrevin is used to identify synaptic vesicles for tethering near the synaptic cleft. Since neurons have a synapse and dendrites, I'd like to know how exactly the vesicles ...
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Why do neurons have a negative resting potential?

Neurons expend the majority of their energy powering ion pumps to maintain the chemical gradients that power their electrical activity. To have a negative resting potential, neurons leak potassium ...
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Disproportion in cranial nerve innervation?

The cranial nerve innervation is highly disproportionate, as far as humans are concerned. I am not sure of the advantage of being innervated by cranial nerve versus being innervated by a normal ...
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260 views

Why is membrane potential not zero at equilibrium?

For the squid giant axon, the membrane potential computed by the Goldman equation is -60mV. And the Nernst potentials are (the differences between the K+ and the Na+'s Nernst potential and the ...
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81 views

If a non-mammal is starved of oxygen for some time, how long would it take the animal's neurons to die?

This is a follow-up question to Why do neurons die so quickly (relative to other cells) when deprived of oxygen?. I'm particularly interested in the case of reptiles, octopuses, and other ...
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How does Sodium Valproate cause neural plasticity

I have been reading a fascinating paper: Valproate reopens critical-period learning of absolute pitch 18 individuals were given Sodium Valproate (VPA) for a fortnight during which they trained on a ...
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Neuroendocrinal mechanism of parturition

My book reads, "The fetus signals that it is mature by secreting certain hormones that diffuse across the placenta into mother's blood and cause the secretion of oxytocin from her posterior ...
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139 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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126 views

Is (Brain Mass)/(Total Mass) still considered a valid indicator of intelligence?

I was reading this(1) and it led me back to ask a very basic question (I'm not a neuroscientist). All the way back to undergrad anthropology and neuroscience courses I remember being taught the ...
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131 views

What protocol does the nervous system use?

I just read How does an inhibitory synapse communicate to the cell body of a neuron? and found myself asking this question ... hopefully I'm not asking the same thing Any body possessed of a nervous ...
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Hebbian theory “fire together” clarification

Donald Hebb states it as follows: "Let us assume that the persistence or repetition of a reverberatory activity (or "trace") tends to induce lasting cellular changes that add to its stability.… ...
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How does a pinched nerve cause pain (at the molecular level)?

Is this due to pressure differentials in the surrounding tissue? (Is it possible to have a pinched nerve without compression of the surrounding tissues, and does this cause pain?) What are the ...
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732 views

How do neurons form new connections in brain plasticity?

I've been reading about brain plasticity and how the brain can "rewire" itself. One of the things that is not clear to me - how neurons can establish new connections. Does this rewiring mean that ...
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35 views

Braquio-abduction illusion explanation and references

Illusion: Lying down on a hard flat floor move arms up and down (as when doing a snow angel) while keeping them touching the floor. While repeating it a few times the floor begins to appear concave, ...
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76 views

How does someone with red-green colorblindness see yellow on a monitor/television?

I recently watched the video This Is Not Yellow explaining how red, green, and blue pixels can be used to create images of all other colors. Since yellow is created with red and green pixels, how is a ...
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Confused at what is happening with these action potentials

Ok so for a bit of a background, I am doing a science project looking at the action potentials of the earthworm. I anaesthatized the worms then hooked them up to a spiker box ...
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What is the core mechanism behind neuroplasticity?

Specifically I am looking at reopening of the critical period of plasticity. Modern neuroscience has started to unlock the secret of neuroplasticity. A common experimental setup is with mice. They ...
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46 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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156 views

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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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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398 views

Why does it hurt more when you touch a nerve directly?

I am not a biologist nor know much about biology (so please explain in layman's terms) however I have always been curious as to why this is. What causes the difference in pain between touching an ...
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62 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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120 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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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 ...