Tagged Questions

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

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0
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1answer
79 views

If inhibiting S6 kinase decreases protein translation, then could inhibiting S6 kinase could possibly slow down long-term potentiation in neurons?

From http://en.wikipedia.org/wiki/P70S6_kinase... Phosphorylation of S6 induces protein synthesis at the ribosome. P70S6 kinase is in a signaling pathway that includes mTOR (the mammalian ...
8
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3answers
329 views

Long-term-potentiation and memory. Where do we stand?

I was reading the answers to the question: How and where, in the human brain, are memories stored? and, as expected, LTP and LTD came out. Every time I read about LTP/LTD there is always something ...
6
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2answers
867 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?
10
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1answer
258 views

Is the minicolumn the unit of the neocortex?

There are many arguments for what the unit of the neocortex is. "Columns" seem to be the standard, but what exactly those are is extremely contradictory between individuals, cortical regions, and ...
10
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1answer
134 views

How reversible is DAT upregulation from long-term ADHD medication use?

A mechanism for ADHD stimulant medication tolerance has now been found. See http://neurosciencenews.com/adhd-medication-patient-brains-adapt-dat/. Here's the thing though: what exactly is the ...
12
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1answer
3k views

How does Golgi's neural histological stain work?

What is known about the targets of Golgi staining of neurons? Are larger neurons more likely to be stained? Are specific cell types more susceptible than others? The current wikipedia article says ...
5
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1answer
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 ...
6
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2answers
814 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 ...
39
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4answers
8k views

How does the brain's energy consumption depend on mental activity?

What is the impact of mental activity on the energy consumption of the human brain? I am most interested in intellectually demanding tasks (e.g., chess matches, solving a puzzle, taking a difficult ...
5
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1answer
141 views

What are the constraints when growing an artificial brain?

Are there any experiments on growing artificial brains from brain tissue? What are the constraints? Will such tissue grown to the mass greater than that of human brain surpass it in intellect or it ...
9
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2answers
1k views

What is Peter's rule in neuroscience?

I have heard and read about Peter's rule informally in the past, but never saw a formal definition or description. Informally I have learned to understand Peter's rule as the assumed correlation ...
11
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2answers
390 views

Could an “overactive” brain increase the chances of Alzheimer's Disease?

From Raichle ME. 2010. Two views of brain function. Trends in cognitive sciences 14: 180–90: Alzheimer’s disease (AD) is the most common cause of progressive cognitive decline and dementia in ...
12
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2answers
490 views

When did vision evolve for the first time?

Today I wondered what the first organism to evolve vision would have been. I assume that it would have been kind of primitive and basic, but of course extremely innovative and eventually useful to a ...
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3answers
1k views

How and where, in the human brain, are memories stored?

Background I am a computer programmer who is fascinated by artificial intelligence and artificial neural networks, and I am becoming more curious about how biological neural networks work. Context ...
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8answers
8k views

Why have humans evolved much more quickly than other animals?

Humans have, in a relatively short amount of time, evolved from apes on the African plains to upright brainiacs with nukes, computers, and space travel. Meanwhile, a lion is still a lion and a ...
14
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1answer
384 views

Is it correct that the body only responds to the most painful stimulus?

I'm rather ashamed to say that this question is partly based on an episode of House. I have previously heard that, if there are multiple simultaneous painful stimuli, the mind will only feel the ...
8
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1answer
98 views

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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1answer
2k views

How do dopamine agonists like amphetamine/methylphenidate affect acetylcholine signalling?

Do they increase it, or is the effect mostly neutral?
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0answers
107 views

If D1 receptors stimulate adenylate cyclase (through GPCRs) and D2 receptors inhibit it, then why do mutations in both have similar effects?

D1 and D2 both refer to specific types of dopamine receptors. I'm sure it has something to do with the fact that the D1 receptors are in regions different from D2 receptors. I know that adenylate ...
10
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1answer
176 views

Do taller people have larger somatosensory cortices than short people?

Do taller people have larger somatosensory cortices than short people? What about larger motor cortices? And if so, could this imply that they have less space devoted to other functions, like ...
0
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1answer
9k 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 ...
13
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2answers
530 views

Are there neurons that can sense light shining in your ears?

I know someone who bought earphones that shine light in you ears. According to what he was told, there are neurons that sense light and then make you feel wide awake when activated, which seemed like ...
6
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1answer
259 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 ...
34
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5answers
1k 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 ...
10
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1answer
124 views

What portions of the brain have drastic changes in activation when we “sense” someone is there?

I was watching an old Arnold Schwarzenegger movie ("Commando") where he plays an elite soldier (surprise). An enemy tries to sneak up on him, and Arnold says that he smelled the other guy ...
8
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1answer
201 views

Is the squid giant axon the fastest conducting unmyelinated axon known?

The conduction velocity of the squid giant axon can reach 30 m/s. Is there any known example of an even faster conducting unmyelinated axons?
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2answers
2k views

How does a brain distinguish stimuli?

If all the brain ever "sees" is action potentials, how do we know that one set of action potentials denotes a flash of light, another one signifies a loud sound, etc ?
16
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1answer
311 views

Why does regular exercise increase brain volume?

It has been shown in several studies that regular aerobic exercise increases brain volume in aging humans. The changes were observed in hippocampus and were correlated with dramatic reduction of ...
10
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1answer
196 views

What would be the conduction speed of A-alpha fibers, were they unmyelinated?

It's known (Hursh 1939) that myelinated axons exhibit the behavior $v = 6d$, where $v$ is the propagation speed [m/s] and $d$ is the axon diameter [μm]. A related relation for unmyelinated axons is ...
9
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1answer
110 views

Are Schwann cells the sole source of myelination in PNS?

Are Schwann cells the only source of myelin for axons in the peripheral nervous system, or are there other neuroglia or other processes that result in myelination of PNS axons?
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2answers
1k views

What causes REM atonia to be lost in sleepwalking?

I understand that in normal REM sleep the voluntary muscles are in effect paralysed in order to prevent an individual acting out their dreams. This paper indicates that there are likley to be ...
17
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2answers
465 views

How is temperature sensed?

Can anyone summarize the mechanism by which when an object of a given temperature is placed in contact with, say, the skin on a human fingertip, the average speed of the particles of the object is ...
7
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1answer
187 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 ...
6
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1answer
117 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 ...
20
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1answer
14k 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 ...
16
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2answers
5k views

How do the brain and nerves create electrical pulses?

I have heard that information is sent between the brain and peripheral nerves via electrical pulses or signals, but I don't understand how they create them in the first place.
10
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2answers
1k views

Do human beings have pheromone receptors?

What is the current consensus on whether or not humans have receptors that detect pheromones? If there are purported receptors, in what anatomical areas are they located? With what organ systems do ...
11
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1answer
699 views

What limits the maximum spacing of Nodes of Ranvier and which organisms tend to have the widest gaps?

Assuming that a longer distance between gaps in the myelin sheath is beneficial for an organism due to the increased propagation speed, what is the limiting factor in determining the maximum spacing ...
14
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1answer
104 views

What are the main mechanisms of interaction between the nervous and immune systems?

We know from pop science that our psychological states have an effect on our immune systems ("worrying ourselves sick", etc.), but what are the actual mechanisms through which our nervous systems pass ...
11
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2answers
205 views

Under what conditions do dendritic spines form?

I'm looking for resources or any information about the formation of dendritic spines and synaptogenesis, especially in relation to how new connections are formed on a daily basis. Does the ...