Questions tagged [neuroscience]
The study of the structure and function of the nervous system and its components.
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What is the outer boundary of oligodendrocyte myelination?
The sensory and motor neurons comprising the spinal cord and brain stem have the interesting property that different structural components belonging to the same neuron can occupy both the PNS and CNS.
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1answer
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When are neuropeptides loaded into vesicles?
It is well known that small neurotransmitters like monoamines (dopamine, serotonin, etc), acetylcholine, glutamate, etc are loaded into vesicles at the axon terminal. Stated differently, synaptic ...
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How are electrical properties differently applied to the soma of a neuron and the axon of a neuron? [on hold]
I have provided two pictures to help clarify my question:
As you can see from the above two images, the values in the two tables are the exact same. Summarizing, the larger soma and larger myelinated ...
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34 views
Monkey Grip Procedure?
How the monkey grip procedure performed about the arms is able to cause a greater stretch reflex response in the leg for the same amount of sensory input when compare to a response without the monkey ...
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1answer
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A speculative question about sensation
I know this is rather speculative and I am not a biologist, but I have womdered about this for a long time.
I have always been able to pinpoint the central line of any part of my body exactly as if ...
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1answer
51 views
Why do larger diameter myelinated axons have greater conduction velocities than small diameter myelinated axons?
A canonical statement I have frequently read is that "large diameter axons conduct action potentials at faster velocities than small diameter axons". After recently learning the effect of increased ...
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Are large cell bodies of neurons harder to depolarize than small cell bodies of neurons?
In order for the axon to initiate an action potential, we know that the axon initial segment must be brought to threshold. So my question is as follows:
Say we have the minimum charge input, "X", ...
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What is the difference in the electrical excitability between a “large diameter soma” and a “large diameter axon”
There are two stereotyped statements that I have seen during my coursework regarding electric properties of neurons:
Large diameter axons propagate action potentials more quickly than small diameter ...
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What phosphorylates tau protein & and what causes tau to be phosphorylated?
I want to know what phosphorylates tau protein and its 6 isoforms.
I know kinases cause phosphorylation events, and in tau it can be phosphorylated in a healthy neuron in the trans conformation, but ...
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1answer
42 views
At What Rate Do Ions Leak Out of a Plasma Membrane Segment That Has No Ion Channels?
In reading about the purpose of myelin during action potential propagation, I came across a point of confusion.
From what I understand, one of the primary "benefits" of myelin is that it aids in ...
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18 views
How many neurons do we have in our forearm?
I am developing a neural interface, getting signals from the forearm and mapping them to hand gestures. The question we have at the moment is what is the upper bound of information bandwidth that we ...
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How would the brain represent represent elapsed time?
When we are waiting for an elevator, we know that the elevator will not open right away. There is a delay of 2 or 3 seconds. How does the brain (likely cerebellum) represent the running time of 2 or 3 ...
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1answer
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Can motor neurons in the brain stem start movements?
Supposedly (consciouss) movement is started in the cerebral cortex. But some time ago I've read a research which stated it might be possible some movements (not specified which ones, probably mean ...
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2answers
74 views
Could a strong magnet field repel the body before damaging it?
Could a magnetic field be strong enough to damage the body or erase the brain?
Blood is slightly diamagnetic, so if the field was strong enough, could it repel a body evenly?
Could a diamagnetic ...
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1answer
21 views
How does (action potential) hyper-polarisation work?
I understand that after depolarisation, repolarisation and then hyperpolarisaiton occurs and that an area in hyperpolarisation is in its "refractory period".
Why does this prevent Na+ ions diffusing "...
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Do non-human primates have mental disorders like humans?
I was at the zoo today and watched a gorilla pick at a scab on its finger, compulsively, until it started bleeding. Is this OCD or is it just a nervous thing that non-human primates do at the zoo? Do ...
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1answer
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Entropy during neuronal signaling
to begin with: I have some background in cognitive neuroscience, but have not intensely studied the biochemical background of neuronal signalling, so please correct me if my basic understanding is ...
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1answer
34 views
Neuroscience and learning of a single neuron [closed]
Can you teach an alphabet to a neuron?
If yes, how?
How does a neuron 'learn' new information, do all individuals learns similarly ?
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1answer
34 views
Origin of different brainwaves
I'm creating a project in which I can measure brainwaves (more or less like EEG). Since I'm not a medical student im having a problem finding the origin or most prominent regions for measurements of ...
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1answer
40 views
Depolarisation of post synaptic neuron
When the post synaptic neuron begins to depolarise as positive sodium ions move into it and it reaches threshold- does the inside of the neuron actually switch to being more positive than the outside? ...
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What cell types comprise the median eminence and the tuber cinereum?
I have tried pretty hard to get a detailed description of what exactly the median eminence and the tuber cinereum are but to no avail. I am very familiar with their anatomical relationships (spatially)...
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1answer
41 views
Multiple numbers in the Ishihara test?
When I was in high school (30 years ago), I took a biology class, and the instructor showed us an Ishihara color test for color-blindness. (This is the "hidden numbers" test.)
What I thought I saw ...
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Does eosinophil-derived neurotoxin attack the helminth nervous system?
I had always assumed that EDN's purpose was to attack the nervous systems of helminths and similar multicellular parasitic organisms, given the function of eosinophils. The enzyme was named due to its ...
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1answer
36 views
What neurons' projections comprise the olfactory nerve (Cranial Nerve 1)?
Recently, I have been learning about olfaction. To my surprise, I am having a heck of a time finding explicit information regarding which neurons' axons are comprising the olfactory nerve. I am aware ...
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How can different ion channels of the same type have different cell responses?
The NMDA receptor is an ion channel and contributes to synaptic plasticity and memory. It is said that calcium ion flux through the receptor is critical for this mechanism. However, there are other ...
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1answer
36 views
Have there been new discoveries concerning the perception of taste for the last 10 years? [closed]
What are the last discoveries concerning the perception of taste for the last 10 years?
We discovered the 5th flavour: umami.
Also the 6th and 7th: oleogustus and starchy.
Anything else?
Maybe in ...
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1answer
40 views
How does fluid pass through the glial limitans into the subarachnoid space?
I have often heard that the cerebrospinal fluid (CSF) and interstitial fluid (ISF) are in free exchange. Because the CSF eventually drains (predominantly) into the dural venous sinuses, ISF's ability ...
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1answer
73 views
Neuronal membrane resting potential for large cells
I'm reading Medical Physiology by Boron and Boulpaep (a really terrific book). In the chapter Electrophysiology of the Cell Membrane, section Membrane Potential Is Generated by Ion Gradients, Not ...
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1answer
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Can cerebrospinal fluid pass through the pia mater or ependymal cells of the ventricles?
During a lecture, a professor commented that the cerebrospinal fluid and interstitial fluid of the brain parenchyma have similar composition because they can exchange with one another. This struck me ...
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29 views
What's a reasonable time constant for a mathematical model of a neuron?
Background
I've been studying various mathematical models of neurons. So far I've covered the classic Hodgkin-Huxley model (to describe the potential difference of a single neuron) and the integrate ...
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1answer
29 views
Analysis of dynamic connectome data?
I have heard about existence of full brain connectome data of some worms or fishes. I have heard about GEVI - genetically engineered voltage indicators - that allow to see voltage data at subcellular ...
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What is the status of the “Free Energy Principle” as a theory of living organisms?
The free energy principle states that biological organisms maintain their order by minimizing a function called variational free energy (VFE).
While it is the case that the minimum to VFE also ...
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1answer
43 views
Is the strength of presynaptic stimulus on the postsynaptic neuron affected more by the dendrites, or the cell body?
Is the strength of presynaptic stimulus on the postsynaptic neuron affected more by the properties of the dendrites & axon terminals, or the cell body & axon?
Two years ago I asked a question ...
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How many “primary colors” can we smell? [duplicate]
There are many more that three visible wavelength in the visible EM spectrum, and yet we can model any color using only three primary RGB wavelength. Perception of an arbitrary color is equivalent of ...
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2answers
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Are spinal nerves myelinated and unmyelinated at the same time?
I was trying to answer this question when I remembered that the somatic axon is myelinated, while both sympathetic and parasympathetic preganglionic axons are also myelinated. Are they only myelinated ...
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1answer
6k views
Do large animals experience a meaningful delay when moving their most distant appendages?
According to the Physics Factbook, nerve impulses travel at speeds anywhere from 1 meter per second up to around 100 meters per second. Blue whales reach up to around 30 meters long.
For a full-size ...
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excitatory-inhibitory synapse ratio
For each inhibitory synapse, how many excitatory synapses are in the brain?
It is the same ratio along the animal kingdom or nervous system areas?
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Understanding the derivation of the Nernst equation
I am trying to understand how the Nernst equation can be derived and am mostly referring to the explanation given in the book Theoretical Neuroscience by Dayan and Abbott.
Given we have a ...
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0answers
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Does intermittent fasting promote neurogenesis through the same mechanism as aerobic exercises?
I heard that intermittent fasting promote neurogenesis through the secretion of BDNF, I heard aerobic exercises does the same through BDNF. Now, I am wondering if there are other mechanisms through ...
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1answer
845 views
What's the difference between the neuroendocrine system vs endocrine system?
This is what I have understood so far:
Neuroendocrine system involved neuroendocrine cells (also known as neurosecretory cells) that receive nerve impulses by a sensory neuron to release ...
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1answer
27 views
Neurons and nerves [duplicate]
What is a nerve compared to a neuron? Is it a collection of axons alone or does it include cell body too? I'm pretty confused of what actually the "nerve" is composed of. I had imagined that the nerve ...
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1answer
41 views
How does a decrease in free Ca2+ result in nerve/muscle overexcitability?
I have in my notes that a decrease in free Ca2+ increases membrane permeability to Na+ so that it is brought closer to threshold, but no further details. So how does this work?
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Stem cells therapy for stroke via thecal sac?
According to this video posted below, stem cells for stroke patients can be induced to thecal sack, below the spinal cord.
Those stem cells would make their way up to the brain.
https://youtu.be/...
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2answers
130 views
Does the brain have a clock and can it be sped up?
Before i start, I'm an engineer and have very limited knowledge on biology and neuroscience. My question is, does the brain have a clock like a computer where it has a set processing speed?
Clocks in ...
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Is there still a convincing argument/evidence that adult neurogenesis does not exist/play an essential role in NON-Human Primates?
Adult neurogenesis in human-being is a debated topic, and will probably take several years to get resolved.
I am under impression that it is relatively easier to settle the debate on non-human ...
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Do reflex movements involve information processing?
According to Reflex
A reflex, or reflex action, is an involuntary and nearly instantaneous
movement in response to a stimulus. A reflex is made possible by neural pathways called reflex arcs ...
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1answer
50 views
What do the acronyms in C.elegans neuron names stand for? [closed]
In this site, I see a variety of acronymic names for C.elegans neurons but what do these names mean (for example AVAL, AVAR)?
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1answer
211 views
Why does sympathetic activity constrict pulmonary vessels?
I don't know understand why sympathetic stimulation constricts pulmonary vessels?
I thought that the sympathetic nervous system activated the body for physical activity. Physical activity would need ...
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1answer
123 views
How do Neurotransmitters get into the neurons?
This may be a dumb question. I'm not a Neuroscientist. I'm just trying to learn more about the brain to improve my AI learning algorithms…
I understand that there are different kinds of ...
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2answers
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How do scientists transfer the specific DNA in Optogenetics?
I'm a bit new to genetic modification and I was wondering in Optogenetics (a field in neuroscience) how the scientists transfered the desired DNA strand from the light-sensitive ion channel opening ...
