Questions tagged [neuron]

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When an action potential reaches an axon terminal

I came across the following question in my study of action potentials in neurons: When an action potential reaches an axon terminal: A. Na+ channels close. B. K+ channels open. C. The interior of the ...
ZSK3914's user avatar
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What are the factors affecting reaction time and/or reflex velocity?

So there was this video of a cat killing a snake: Cat reaction time and another of a bobcat killing a rattlesnake Bobcat kills rattlesnake And then this from wikipedia on sand cats: In the Ténéré, a ...
Aurelius's user avatar
5 votes
2 answers
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Is colocalisation of a protein with a presynaptic marker sufficient evidence to say that the protein is a component of axon terminals?

I am reading journal papers about the subcellular localisation of the insulin receptor (IR) in neurons. I have read a paper stating that IR is highly enriched at synapses, localising to both the ...
ceno980's user avatar
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Which co-transmitters are released first?

I understand that a single neuron can release different neurotransmitters depending on the frequency of its stimulation (see https://www.ncbi.nlm.nih.gov/books/NBK10818/). As the frequency of ...
Jim Doe's user avatar
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Have the potential therapeutic applications of cell fusion between cancer cells and neural cells been investigated?

Studies have appeared on the possible role that cell fusion plays in the formation of certain cancers. For instance, Sitar et al. (2019) have looked into the process of cell fusion in the formation of ...
Max Muller's user avatar
1 vote
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How does the central nervous system create the feeling of physical sensation in our consciousness? [closed]

I know sensory neurons that respond to light and physical sensations (pressure, temperature) exist throughout our body, giving us information about our surroundings. For instance, when I push the tip ...
bhp's user avatar
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Confusion regarding the location of myelinated and unmyelinated nerve fibres

So, what I understand by neural system terms is Central nervous system [CNS]- consist of brain and spinal cord Peripheral nervous system [PNS] - consist of cranial and spinal nerves (all the nerves ...
Cerebral cortex 's user avatar
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1 answer
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How does a neuron change its function, without changing its synaptic connections?

How does a neuron change its characteristics in order to change its function, without changing its connections with the neural networks? Basically, do any organelles change their properties and are ...
eengeeneer's user avatar
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To what extent are microtubule-filaments present in astrocyte leaflets?

I have been trying to find information about whether microtubule filaments are present in the leaflets of astrocytes. A astrocyte can have quite varied morphology but many at least, have a star-like ...
thehorselessheadman's user avatar
6 votes
2 answers
268 views

Neurons: how does the brain reduce electromagnetic interference?

I read that the frequency of signal over neural ion channels in the brain can range from .19 Hz - 30 Hz at low voltage. For an interference example, AC electricity is 60 Hz at high voltage and ...
Nick's user avatar
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Vision System: neural activity is modulated using FSK?

I’m learning about the human vision system and signaling. Does anyone know if the signaling used by the vision system is modulated at the neuron using amplitude frequency shift keying? I present my ...
Nick's user avatar
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Vision and signal through the nervous system? [closed]

I have questions regarding the signal path between the retina and other parts of the brain. An understanding and then questions in bold follow. Wikipedia states: Retinal ganglion cells spontaneously ...
Nick's user avatar
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2 votes
1 answer
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The role of PCA (Principal Component Analysis) in recording neurons

I am reviewing the recording methods from an experiment that tracked neuronal activity on the prefrontal cortex of a monkey. From the method description in Nieder, Andreas, David J. Freedman, and Earl ...
nelv's user avatar
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0 answers
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Is the nervous message sent by an eyelash being flexed sent all the way to the brain?

Since the reflex to close the eyelid once an eyelash is touched seems very fast, does the signal from the neuron detecting the touching travel all the way to the brain, get processed then back to the ...
Dolanor's user avatar
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2 votes
2 answers
771 views

Why are nerves blocked even though potassium channels are not blocked?

One could read "Local anesthetics produce a very slight, virtually insignificant, decrease in potassium (K+) conductance through the nerve membrane." At Handbook of Local Anesthesia 7th ...
Quique's user avatar
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Illustrating Action Potential Conduction and Ion-Gated Channels

I can separately illustrate action potential and ion-gated channels along an axon. However, I am not sure if I did the right thing on the picture below. What I'm trying to show are the simultaneous ...
thepajama's user avatar
4 votes
1 answer
377 views

Are living cells electrically neutral?

I found random scientific table which had a comment attached: the cells must be electrically neutral. Per my knowledge whole intracellular solution contains more electrons than protons (definition ...
Lasha Bukhnikashvili's user avatar
-2 votes
1 answer
255 views

How many signals can one neuron send and/or receive simultaneously?

I've been researching this question online and finding opposing answers. Some articles say that one neuron can only send one signal at a time while others says that one neuron can send more than one ...
user67614's user avatar
3 votes
3 answers
691 views

Is there a difference between human neuron cells compared to those of other animals?

Thanks for looking. Firstly, I am nowhere near biologist, just a student, so my apologies if this isn't a "good" question. Background: So I was searching about intelligence, brains and ...
Zombie Chibi XD's user avatar
2 votes
1 answer
73 views

Cumulative synaptic transmission delay

Assume the following: there are at least 10^11 neurons in the human brain there are approximately 10^14 synaptic connections in the human brain (because on average each neuron gets inputs from ...
JimPanSee's user avatar
1 vote
1 answer
67 views

Connectivity Relation between axon terminal synapses and dendrites

With regards to the synapses between axon terminals and dendrites, what is the relation between a given neuron's axon terminals and its neighbouring neurons' dendrites? Does each axon synapse on only ...
Peter's user avatar
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How are thoughts biologicaly generated?

I want to know how thoughts are biologicaly generated. I know that electrical impulses can trigger formed memories in the brain but what I want to know is how the electrical impulse is generated in ...
Ganesh Shakti Kozak's user avatar
2 votes
0 answers
56 views

What are "inactive" cells during Ca2+ imaging of neurons?

I am reading this paper, and have found the following Figure (Extended Data Figure 5) where they show maps of active cells in the amygdala as imaged with a miniscope and GCaMP6m: Legend: Using the ...
Pugl's user avatar
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3 votes
1 answer
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Are synaptic boutons always located on axons?

I am learning about the protein Synaptophysin and I have read that it is an integral membrane protein localised to synaptic vesicles. I have also read that it is a specific and sensitive marker for ...
ceno980's user avatar
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1 answer
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What is meant by the term synaptic targeting?

I am studying whether a protein interacts with the mitochondria in the synapses of neurons and I have come across the term "synaptic targeting". I am reading this paper and I have come ...
ceno980's user avatar
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2 votes
2 answers
313 views

Are sensory mechanoreceptors and mechanical nociceptors the same type of neurons or are they different?

I always supposed the neurons / receptors which transmitted touch and pain were the same, since they react to stimulus which are the same but with different intensity, and they just sent a stronger ...
Pablo's user avatar
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1 vote
0 answers
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Why is neuronal firing rate proportional to axonal diameter?

I know that a larger axonal diameter results in faster speed of action potentials due to reduced resistance. However this doesn't explain why the firing rate of neurons is proportional to neuronal ...
Bryan Chang's user avatar
1 vote
0 answers
25 views

Using coefficient of variation (CV) for GCaMP6 'synchronised episode' spikes, good idea or not?

Using GCaMP6 we have recorded fluorescence activity of kisspeptin neurons that exhibit synchronised pulsatile firing activity. I measured the intervals between each episode, which are quite variable. ...
Bryan Chang's user avatar
1 vote
0 answers
73 views

Are axons of neurosecretory cells in neurohypophysis myelinated?

According to the pictures that I found in textbooks and Google here these neurons are not myelinated. I just wanted to be sure. They are not myelinated, are they?
a.RR's user avatar
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2 votes
1 answer
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How are neurons selective towards specific stimuli?

I've read several papers that mention that there are specific neurons that are activated for specific things (e.g. neuron A activate only when horizontal lines appear, neuron B activate when certain ...
Max K's user avatar
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4 votes
1 answer
71 views

Can potassium ions depolarise neuron membranes?

I am reading a journal paper about the cell adhesion molecule NCAM2 and I have come across the following statement: To confirm the functionality of the reporters, neurons were time-lapse recorded ...
ceno980's user avatar
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Do neurons with dopamine inside only send signals to another neuron with dopamine?

A nerve cell with dopamine receptors gets an action potential and releases dopamine to other neurons. Does this nerve cell only release to cells with dopamine inside? Because what if a neuron has a ...
eliasogelias's user avatar
1 vote
2 answers
376 views

Do voltage-gated channels in a neuron use ATP

I have a question about action potentials in a neuron. Do voltage-gated sodium and potassium channels use ATP? I mean when they are closed or when they want to open the gate, do they use ATP?
Amirni's user avatar
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6 votes
1 answer
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Why do ion leak channels exist?

I've recently learned about ion leak channels in the context of membrane potential and action potentials. Neurons have ion pumps that require energy in order to maintain the resting membrane potential ...
Nicholas Hassan's user avatar
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0 answers
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Na+ / K+ ATPase: How does it restore resting membrane potential? [duplicate]

Could not find any sources talking about this (in a clear manner). If the Na+ / K+ ATPase pumps 3 Na+ out for every 2 K+ it pumps in, thus making the cell more negative, why is the Na+ / K+ ATPase ...
Ally's user avatar
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Why does exposure to a smell for some time reduce the electrical response of receptor neurons in the olfactory system?

In what way does exposure to a certain smell for some time causes them to loose sensitivity and have a lesser electrical response
Octavylon's user avatar
1 vote
0 answers
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Biophysically, how to change from a tonically firing neuron to an occasionally firing one?

In terms of membrane properties, size and neuronal biophysics (assuming no change in incoming excitation), how can a tonically firing neuron become (say during development) an occasionally bursting ...
user7956644's user avatar
0 votes
1 answer
43 views

What is a neuronal loop?

Stanford Medicine's OCD page says that Many investigators have contributed to the hypothesis that OCD involves dysfunction in a neuronal loop running from the orbital frontal cortex to the ...
ds_secret's user avatar
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1 vote
0 answers
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How would blocking Na/K ATPase affect the ability of a neuron to exhibit a series of action potentials?

Neural firing usually occurs in the form of spike series. Several action potentials are happening in a quick succession. Whereas Na/K pumps (and other pumps) restore ion gradients to allow processes ...
Haliaetus's user avatar
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Typical firing patterns of neurons in the default mode network in resting state

Inspired by the Wikipedia article on the default mode network where I read: Hans Berger, the inventor of the electroencephalogram, was the first to propose the idea that the brain is constantly ...
Hans-Peter Stricker's user avatar
3 votes
1 answer
54 views

Where do the Ca ions that causes neurotransmitter release from synaptic bouton, come from?

I hope the information you share will help clarify the following doubts and gaps in my knowledge: Where do the Calcium ions in the influx (which then triggers the neurotransmitter vesicles) come from?...
pulkitsinghal's user avatar
2 votes
3 answers
708 views

Functional unit

What is meant by functional unit of a system? Like when we say that the neuron is the basic unit of neural system, do we mean that all those things that are performed by neural system can be performed ...
user55780's user avatar
0 votes
1 answer
117 views

Why didn't the human Cerebrum evolve to have granule cells like the Cerebellum does?

The Cerebellum is much smaller compared to the Cerebrum yet it contains more than half of the total neurons contained in the brain. That's mainly due to the granule cells in the Cerebellum which ...
Louie's user avatar
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1 vote
0 answers
41 views

Effect of myelination on inteligence in cephalopods

Cephalopods are known for their unique intelligence compared to other invertebrates. The number of neurons of cephalopods is of the order $5*10^8$, similar to dogs. Humans have about $10^{11}$ ...
Qoray's user avatar
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1 vote
2 answers
1k views

Myelination and time constant

In textbooks, it says that myelination doesn't really affect the time constant as tau=RC where R is the membrane resistance and C is the membrane capacitance. Myelin increases membrane resistance ...
Sharon's user avatar
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2 votes
1 answer
1k views

What causes sodium channels to open?

What triggers the opening of sodium channels in a neuronal membrane? Is it acetylcholine that activates sodium channels in the postsynaptic membrane? Are sodium channels like receptors that have to ...
stressed out's user avatar
3 votes
1 answer
2k views

Understanding presynaptic and postsynaptic inhibition

One way to classify neural inhibition is based on the inhibition being "presynaptic" or "postsynaptic". As far as I understand, the two different types of inhibition refer to the following: ...
Pugl's user avatar
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2 votes
1 answer
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Relationship between membrane current and voltage in neurons

Depolarization of neurons leads currents of different magnitudes flow in or out of the cell, and the Sodium and Potassium currents can be separately plotted (Purves): Caption: Relationship between ...
Pugl's user avatar
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1 vote
0 answers
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How long does it take the neurotransmitters to diffuse accross the synaptic cleft?

Neurotransmitters get from the pre-synaptic neuron to the receptors on the post-synaptic neuron by diffusion across the gap between these two (the synaptic cleft). My question is, how much time does ...
Alex L's user avatar
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1 vote
1 answer
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When do the first neurons appear in humans?

According to this Neural Plate The neural plate appears in day 18 in humans (very specific). and according to this Neural Plate (wiki) The progenitor cells that make up the precursors to neural ...
Pablo's user avatar
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