Questions tagged [neuroanatomy]

Study of the anatomy and organization of the nervous system.

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Is C. elegans always observed with precisely 302 neurons? Are there ever individual viable exceptions?

This answer mentions that the C. elegans hermaphrodite has exactly 302 distinct neurons. This has made it a very effective model for a variety of types of biological research, including neurology and ...
uhoh's user avatar
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Why is the brain white?

I have read many articles about how the brain is the most power-hungry organ in any living complex organism, requiring about 70% of it's oxygen supplies in the resting state. Since the usual medium ...
haxkalibrr's user avatar
34 votes
3 answers
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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 &...
Matt Cashatt's user avatar
22 votes
1 answer
791 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 age-...
Aleksandra Zalcman's user avatar
18 votes
1 answer
563 views

The human brain in numbers I: neurons

Even though knowing the number of neurons in a functional unit or with the same function is not of main importance, it may be interesting to know their orders of magnitude, especially in the human ...
Hans-Peter Stricker's user avatar
15 votes
1 answer
808 views

Unilateral damage to vagus nerve

Context: The vagus nerves supply the neck viscera, heart, lungs and gastrointestinal tract. They join around the oesophagus to form the oesophageal plexus. Question: Would damage to one vagus nerve ...
Hernandez's user avatar
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What are the advantages and disadvantages of being ambidextrous?

Most of us have one dominant hand. We find it nigh on impossible to do very delicate or dextrous activities with our other-hand. This seems like an apparent weakness, and a rather odd one when you ...
JayRoth's user avatar
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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 ...
Alex Stone's user avatar
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Do taller people have larger somatosensory cortices than short people?

When we assume that peripheral touch receptor densities are equal in tall and short people, then tall people should have more touch receptors than short people, given the larger amount of skin surface ...
InquilineKea's user avatar
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Do memories have mass?

If it were possible to live forever, would our brains grow infinitely with the number of memories that we store? Or would we remove old memories as we create new ones?
AlexBrand's user avatar
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Why can't our eyes smoothly transition from side to side without focusing on a moving object?

Why are we not able to slowly and smoothly look from side to side, or up and down in a single and smooth transition, given that we are able to do this if our eyes are focused on a moving object?
Programmer's user avatar
10 votes
1 answer
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Where is the aneurysm in this picture?

I'm a curious person, I've never had any medical training, but I wish to know some more about aneurysms. Aneurysms are basically weakened spots in the elastic artery wall. This can eventually result ...
undefined's user avatar
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Foveal ganglion cell density (Tay-Sachs Disease)

I’m currently reading on Tay-Sachs disease and have stumbled upon something regarding the typical “cherry red” macula symptom. On the one hand it is mentioned that the macula is almost devoid of ...
mivilar's user avatar
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Why has evolution made neurons use spiking?

I'm going to be forward and say that I'm not a biologist. I don't claim to fully understand the functionality of a neuron from an electrical/chemical perspective... I'm curiously gazing from the ...
TND's user avatar
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Why do humans alone have the capability to have religious/spiritual experiences?

What is it in our brain that makes having such experiences possible? I assume other species don't have these. Sure there are instances in the natural world where you can see individuals of the species ...
deostroll's user avatar
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Is there any way a human could whistle and be unable to speak?

Is there any situation anatomically, where a human could understand the speech of others perfectly, without any capabilities of speech themselves, but would retain the ability to whistle with a tune? ...
Mike.C.Ford's user avatar
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1 answer
780 views

How are bones growing, if bones are not connected to the brain?

If the bones are not connected to the brain, how is their growth controlled? This question is not a duplicate of the question Mechanisms of bone growth, as this question deals with how bone growth is ...
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9 votes
1 answer
342 views

What is this structure in human brain?

Scientists made a new image of brain. I wonder, what is this arc (denoted by blue)? Is it the caudate nucleus?
Dims's user avatar
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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 ...
Stan Shunpike's user avatar
8 votes
2 answers
3k 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 ...
Stan Shunpike's user avatar
7 votes
3 answers
568 views

Do self-exciting neurons exist?

I have two questions concerning self-exciting neurons in the brain. Have directly self-exciting neurons been oberved, i.e. neurons with an axon terminal building a synapse with one of its own ...
Hans-Peter Stricker's user avatar
7 votes
3 answers
991 views

What exactly is Tinnitus?

What exactly is tinnitus? What is it's cause, and why do some people hear it and others don't?
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7 votes
1 answer
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Are there any known rules that neurons always follow while transmitting/receiving signals?

I'm new to neurobiology so I don't know much about it. However, I have worked on artificial neural networks. Man-made AI networks all follow a handful of simple rules. I was wondering if biological ...
Rainer Plumer's user avatar
7 votes
2 answers
3k 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?
nico's user avatar
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Cortical projections from layers 2/3 back to 4?

As all excititory neurons in layer 4 are stellate - they have no apical dendrites that could project to layers 2/3. However, I have seen some diagrams showing axonal projections from layers 2/3 back ...
sebjwallace's user avatar
7 votes
1 answer
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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 ...
user1480431's user avatar
7 votes
1 answer
703 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 ...
walkytalky's user avatar
7 votes
1 answer
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What would happen if some neurons are unmyelinated?

I know that cold receptors have myelinated axons and heat receptors don't. From a physiological perspective, what could be the consequences if cold receptors were unmyelinated? Would that pose some ...
JM97's user avatar
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Neuronal coordinates of C.elegans

Is there a list of neural coordinates for C.elegans? I need it to build a 3D model. Update: What is available at the moment is: full connectome for example, at openconnectome; neuron description ...
Alexander's user avatar
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7 votes
1 answer
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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 ...
stochastic13's user avatar
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6 votes
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Neurons with thousands of connections: where are the extra connections coming from?

If every neuron has only one Axon but can can have thousands of (or let's say, even just ten) incoming Axon connections via its dendrites, where are the extra connections coming from? It seems to me ...
J.Todd's user avatar
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Would the human body react faster to touch or sight

I am currently working on an assignment for my physics class, but I believe my question is biology related. For a two person lab, I am trying to time how long it takes a tennis ball to fall two ...
Citrus Ozel II's user avatar
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1 answer
510 views

Is there a quantitative report for cortical homunculus?

Almost all websites that I see for cortical homunculus only show the final picture with some qualitative descriptions such as "hands have more dexterity and occupy more motor cortex." But is ...
Saeed Neamati's user avatar
6 votes
4 answers
573 views

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.… ...
kalfasyan's user avatar
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6 votes
3 answers
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What exactly is the neural receptive field?

Neural receptive fields map the spatial or temporal distribution of the data to individual neuron excitation, if I understand correctly, but I do not understand if receptive fields (especially in the ...
Dev Kanchen's user avatar
6 votes
1 answer
10k views

Can the dendrites of sensory neurons be a meter long?

The typical textbook structure of neurons is a cell with a short dendritic tree and a long axon. The dendrites receive information and send it to the axon via the cell body (soma). The axon is a long ...
Felix_17's user avatar
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6 votes
1 answer
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Why ambidextrous persons are so rare?

According to this article, only about 1% of all humans are ambidextrous: About 90 percent of people are right-handed, says Corballis. The remaining 10 percent are either left-handed or some ...
Alexei's user avatar
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6 votes
1 answer
399 views

Which organisms have the neuroanatomy Roger Penrose supposes play a role in consciousness?

In The Road to Reality, Roger Penrose suggests that certain brain structures might play a role in consciousness Most particularly, lattice neuronal microtubules, as originally suggested by Stuart ...
magnetar's user avatar
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1 answer
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Nerves, Neurons, Axons and Dendrites by Example

Here is a simple diagram of a neuron: A few (very closely related) questions: Where are receptors located (for pain, pressure, temperature, etc.): in the axon terminals or the dendrite tree? Please ...
smeeb's user avatar
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6 votes
2 answers
338 views

Are there any organisms, extant or extinct, that have only one neuron?

Nervous systems are useful in one way because they allow for integration of complex information. They are also useful because they transmit information very rapidly, over a large distance. However, ...
StarlightDown's user avatar
6 votes
1 answer
818 views

Do people with congenital analgesia feel cold?

There are a few diseases that cause an insensitivity to pain. This question asks about the relationship between the cold and pain, which got me thinking: Is shivering a response driven by the ...
James's user avatar
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Long term effects of "brain freeze" on the cerebral vasculature

According to one theory, ice cream headaches are caused by an increase in blood volume of the anterior cerebral artery: Another theory into the cause of ice-cream headaches is explained by increased ...
jonsca's user avatar
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6 votes
1 answer
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What happens if nerve impulses go the wrong way?

So in nerve impulses, I get that the refractory period is important because it stops the action potentials going the wrong way along the axon. I have two questions: What would the impact be of the ...
emilysmith268's user avatar
6 votes
2 answers
606 views

Why do the brains of cocaine-users shrink faster than the brains of non-cocaine users?

http://news.sciencemag.org/sciencenow/2012/04/cocaine-may-age-the-brain.html?rss=1 Cocaine-dependent individuals showed a significantly greater-than-normal age-related decline in gray matter in ...
InquilineKea's user avatar
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5 votes
2 answers
769 views

Neuron connectivity- how are they connected physically

If Neurons are only connected through synapse and there is no physical connection, how are they just suspended in brain layers?
Anon's user avatar
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1 answer
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Can turkeys run around when their head is cut off like chickens do?

Chickens may run around after their head is cut off if the head is severed near the base of the skull leaving the brain stem intact and missing the jugular vein. This usually only lasts for a few ...
wanderweeer's user avatar
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5 votes
1 answer
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What is synaptic bias?

In non linear model of a neuron there was a mention about bias (Bₖ) which was the summation of the synaptic weights. I want to understand what synaptic bias is and their application/use in neuronal ...
Shiva's user avatar
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5 votes
2 answers
1k views

What is the specific role of the cerebellum when it comes to 'coordinating movement'?

In elementary biology (high school level in the UK - A levels), we are told that the cerebellum is the part of the brain that 'coordinates movement'. Literally nobody takes the time to explain what ...
Mathematician's user avatar
5 votes
2 answers
9k views

Headshot = instant kill? [closed]

While whatching a film, I've been thinking about how does a headshot kill someone, and how long does it take? For example let's say you've beeing shot by a normal (police) handfired weapon - no ...
Thomas Z.'s user avatar
  • 153
5 votes
1 answer
575 views

Neuroscience of mathematicians

I've tried to google this but everything that comes up are things like "mathematical neuroscience" rather than the other way around. Specifically, I'm interested in the workings of a mathematician's ...
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