Questions tagged [neurophysiology]

The study of the physiology of the nervous system, with emphasis on transcellular communication, and cellular and molecular processes involved in neural communication.

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Are different brain wave patterns caused by a change in neural polarization values?

As brain waves have to do with neural oscillation, I am wondering the correlation and cause effect of this. Is it as the question states, or is it the reverse? If it is neither of the two, feel free ...
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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?
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Specified effect of trans cranial electric stimulation on neurotransmitters

Can a specific voltage from a trans cranial stimulation activate specific neurotransmitter receptors or channels? By specific, it means receptors dedicated to specific neurotransmitters such as ...
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Type B Nerve fibres cause exactly what kind of autonomic sensation to the preganglionic neurons?

Ganong's Review of Medical Physiology (25th ed) presents the Erlanger and Gasser classification of mammalian Nerve Fibres as such: Type B Fibres are concerned with Preganglionic autonomic sensations, ...
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What is the correct value of Neuronal Resting Potential - is it -65mV or -70mV?

Some books show the resting potential of neurons as -65mV, such as Neuroscience: Exploring the Brain, Fourth Edition (2016, published by Wolters Kluwer). However, a majority of internet sites, ...
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Why is the ratio between action potential and threshold value called the 'safety factor'?

"All­or­Nothing Principle. Once an action potential has been elicited at any point on the membrane of a normal fiber, the depolarization process travels over the entire membrane if conditions are ...
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How does the original ionic distribution restore after synaptic transmission

During synaptic transmission the calcium ions around the presynaptic membrane diffuse in due to the influx of Na+ ions and the resulting depolarization. This happens because the calcium channels are ...
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Hodgkin-Huxley Model and Propagation of Action Potential

I'm studying Hodgkin-Huxley model of action potential, and I have some confusion. In the well-stated HH model, we have time constants for each ion currents, described as the reciprocal of the sum of ...
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How does expansion of the skin via mitosis influence the density of its specialised nerve endings

I found a reddit question Do nerves & nerve endings expand with skin or does skin expansion causes loss of nerve density where a user references the study Assessment of Epidermal Nerve Fibers: A ...
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Latency differences between our senses

I would be interested in knowing how long it takes between the moment something touches our skin and the moment something is activated in the brain. Also how long does it take in total until we ...
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Differences between comatosed states and brain death

What are the neurological, physical, etc. differences between someone who is in a coma (one that is not medically-induced) and someone who is colloquially deemed "brain dead" (being ...
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Direction of impulse at Axo-axonic synapse and dendro-dendritic synapses

Do axo-axonic and dendro-dendritic synapses show some different impulse conduction directions than the usual dendritic (of carrying impulse towards cyton) and axonal nature (of carrying impulse away ...
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Why is there a notch in the Na curve for an action potential?

Just out of curiosity, why does the Na curve dip down like in the figure below? I can't seem to find an explanation!
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In-plane rotation of vectors of neural population responses

In this paper on fear conditioning, the following is given: The n-dimensional population vector (activity of n neurons) evoked by the conditioned stimulus (CS+, auditory tone) before conditioning The ...
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1answer
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Comparing angles between population vectors of neural activity

I am reading this paper on fear conditioning, where the following is given: The n-dimensional population vector (activity of n neurons) evoked by the conditioned stimulus (CS+, auditory tone) before ...
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1answer
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Why does increasing the space constant increase conduction velocity in myelinated neurons if nodes of Ranvier are constantly spaced?

If depolarisation at one node of Ranvier triggers, by passive conduction, an action potential at the next node of Ranvier, why does increasing the space constant increase conduction velocity? Surely ...
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Help me understand voltage patch clamping

Before I type my question it is important to know that I already tried looking this up on my own and could not find an answer because the answers are all in complicated physics terms and this topic is ...
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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 ...
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What causes paresthesia from compression?

Compression of a nerve causes loss of afferent and efferent information in it. What is the physiological basis of this?
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Would tinnitus be explained by perpetually-bent/opened hairs in the cochlea?

When I look around for what causes tinnitus and the like, the usual response is "Well, loud sounds and hearing damage" but I feel like that's a little plain and I am curious about the ...
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How does pressure travel through the cochlea exactly?

I cannot find this answer anywhere. What I do know is that the stapes pounds on the round window of the cochlea and this causes the fluid to move inside the cochlea itself, which has the three ...
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Why do water molecules diffuse along axons direction?

I am studying tractography technique which aims to reconstruct bundles of axons in brain by following the diffusion direction of water. It is very interesting because it is non-invasive. It exploits ...
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2answers
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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 ...
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Which animals can see (or feel) the Moon’s infrared radiation?

The luminosity (bolometric) of the Moon in infrared is several times greater that its luminosity in visible light. Moreover, it may be rather possible for the Moon to be obscured by some fog or haze ...
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Has anyone tried using functional near-infrared spectropathy to quantitively measure sodium concentrations in the brain?

Functional near-infrared spectropathy "fNIRS", is a biophysics/medical technique that uses the near-infrared part of the electromagnetic spectrum (around 680nm to 810nm in wavelength) to ...
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Distribution of hearing loss

Low-frequency sounds are more penetrating, damaging. Hearing damage caused by blasts typically occurs at frequencies around 2 - 8 kHz, while age-related hearing loss starts at the high frequencies. ...
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Does GABA enhance or inhibit negative effects of glutamate? [closed]

A study on NCBI studied the correlation between a depressive mood and chronic pain. I researched this because today I noticed unusual emotional volatility as a result of 2 days of acute back pain ...
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Why don't sodium Voltage Gated Channels open during Repolarization?

During Depolarization the Sodium VGC open when they receive the Threshold Stimulus. But when Repolarization occurs there comes a point when the cell interior has exactly the the same potential that it ...
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Are neurons capable of buffering a signal to sync up with other data?

The brain is the most complex thing that mankind discovered thus far in the universe. Super computers aren't able yet to outperform the human brain (running only on ~25 watt or so) on the domain of ...
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Biological Neural Network Modification to Unlearn Understandings [closed]

Lets assume that a person grows up thinking that religion X is true religion. So he builds up a profile in ones head and when notion of religion X appears the neurons that is related are fired, giving ...
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Could eidetic memory be related to glial cells?

I am a plasma physicist so I apologize in advance for my biology ignorance. I recall from a neuropsychology class I took in college (used Lezak, Howieson, and Loring, 4th Edition) that there are ...
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How does the brain initiate the process of releasing the neurotransmitters?

Just reading up on the basics of neuroscience. Had a basic question on the signal generation. I understand the concepts of sodium, potassium pumps and how the action potential travels through the axon ...
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Why is saltatory conduction in myelinated axons faster than continuous conduction in unmyelinated axons?

How does spacing apart sodium and potassium channels allow the action potential to travel faster down the axon? This is the reason always cited for saltatory conduction and myelination, but my mental ...
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How are cardiac cells connected by intercalated discs?

I understand that intercalated discs run transversely across the longitudinal axis of the muscle. But what I don't understand is how this same disc binds the cardiac cells together. Are the cells ...
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What are kinesiological factors? [duplicate]

I am in search of a term that describes movement, or practice of motor skills, as a factor of laterality. Would "kinesiological" be appropriate? I'll leave my two previous questions down ...
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1answer
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What does sympathetic and parasympathetic 'tone' mean?

My professor's lecture notes say that " The basal rate of firing is called “sympathetic tone” and 'parasympathetic tone" , but a table I found on the internet says that the parasympthetic system has ...
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Presynaptic inhibition

For presynaptic inhibition, I am aware of these: Ca²+ influx (into the presynaptic nerve terminal) is decreased. And this in turn reduces the probability of releasing synaptic vesicles from the ...
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1answer
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What phase of Action Potential (AP) exactly defines the Relative Refractory Period?

I am posting below, word for word, two statements made on Relative Refractory period - the first from the text: Human Physiology for Medical Students by Magdi Sabry, and the second from a web page ...
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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?
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Does electrotonic spread/conduction occur in saltatory conduction?

Even as textbooks, and almost all web pages I've seen so far, explain electrotonic spread/conduction as the passive current flow along an axon, they do so with continuous conduction only. Apart from ...
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What percentage of the brain is memory | Storage of thoughts, episodes

I was reading the article, in which it is mentioned that human brain constitutes 2.5 petabytes of memory. This made me wonder how much of the brain is associated with memory itself. If we categorize ...
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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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How much oxygen does a brain consume?

I am not a biologist - my background is in quantitative sciences, and I am trying to answer a rather quantitative question: How much oxygen does a brain consume? This however raises many sub-questions ...
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How does increasing the temperature increase the compound action potential in some nerve cell?

In majority of nerve cells, action potential decreases with an increase in temperature.But a couple of papers I have looked at say some nerve behave in the opposite manner (https://pubmed.ncbi.nlm.nih....
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Phantom Limb | Is that even possible?

I am fascinated by the fact that an amputee can control their robotic arm by thinking of the actions they would normally execute when the limb was present. The mind sends signals to the nerve endings ...
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Why Is Action Potential Propagation Not Described by Telegrapher's But Cable Equation?

In modelling the propagation of action potential in an axon, why is the partial differential equation the cable equation rather than the telegrapher's equation? The difference between the two is that ...
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625 views

Can Two Opposite Running Action Potential Cross Each Other without Annihilation in One Axon

Can two opposite travelling action potential cross each other annihilation in an axon? My answer would be affirmative. If the propagation mechanism is linear as described by https://en.wikipedia.org/...
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Action potential attenuation in unmyelinated axons vs demyelinated axons

I learnt that action potentials travel much faster along myelinated axons, and when these axons are demyelinated the action potentials travel much slower and sometimes die out. Why do action ...
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Topography of motor deficit and spasticity in UMNS

As a medical student, I have been told that upper motor neurone syndrome is a cause of motor deficit and spasticity. The motor deficit is said to be affecting predominantly the extensor apparatus at ...
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Why does resting potential not become continually more negative?

(Firstly, I know this is similar to other questions, but I have read those answers and they do not really cover this topic). My understanding of resting potential: action potential is not being ...

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