Questions tagged [neuroscience]

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

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1answer
174 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
365 views

Red neurons - Acute neuronal injury

“Red neurons” are evident by about 12 to 24 hours after an irreversible hypoxic/ ischemic insult. The morphologic features consist of shrinkage of the cell body, pyknosis of the nucleus, disappearance ...
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Why Do Nerve Signals Get Crossed?

First off, I don't know if this is a normal healthy thing to occur. There have been many times where I have an itch on say my arm and I scratch it, only to feel the scratching elsewhere on my body. I ...
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151 views

How do we share pain?

When somebody else tells me about his or her itching or pain in some specific body part, I sometimes begin to feel similar feelings. I can think of about three explanations: I feel pain all over my ...
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1answer
215 views

Can upper motor neuron lesions cause hypotonia?

I have been taught that hypotonia is always caused by lower motor neuron lesions while hypertonia is by upper motor neuron lesions. However, I recently learned of an entity called central hypotonia, ...
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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 ...
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2answers
267 views

Why do neurons have long axons but short dendrites?

Cian O'Donnell, a British neuroscientist, originally asked this question on Twitter: https://twitter.com/cian_neuro/status/1075432086692089857. I am not a biophysicist by training but I wonder whether ...
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1answer
511 views

What is the limit of time resolution in fMRI?

I was reading about a few studies on estimating functional connectivity between brain areas using fMRI signals. However, as far as I know that fMRI has a very poor time resolution, roughly in the ...
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1answer
87 views

What type of movement is “spontaneous movement” if it isnt reflex movement and it isnt purposive movement?

According to Spontaneous and induced fetal activity Spontaneous motor activity of the foetus depends significantly ot the foetal age; during the period between the 12th and 16th week it was ...
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1answer
96 views

Do Colorblind People Have Stronger Sensitivity in Their Other Remaining Cones?

I came across this paper Color defect and color theory. The paper explained about how unilateral color blind (people who color blind only in 1 eye) actually see less bright in their color-blind eye (...
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2answers
680 views

What would happen if brain neurons did not reduce their sensitivity to neurotransmitters after prolonged exposure?

From my understanding, neurons decrease their sensitivity to neurotransmitters by reducing the amount of receptors on the cell membrane in response to sustained neurotransmitter activity. One ...
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1answer
454 views

Can acetylcholine leak away from the synapse and cause spasms?

I am currently studying Pharmacology and a question came to mind. We know that Acetylcholine is used as a neurotransmitter in the neuromuscular junction, both Sympathetic as Parasympathetic, but as I ...
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141 views

Can light function as a neurotransmitter?

Any animal with an eye has photoreceptors, which are essentially light-sensitive neurons. Green algae have channelrhodopsin, which are ion channels that open and close in response to light. Clearly, ...
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Are $DCX^{-}PSA-NCAM^{+}$ neurons the result of adult neurogenesis in human being?

A recent study by Sorrells et al. (2018) has stirred a debate whether human being really do have adult neurogenesis in hippocampus or not. In a following paper- Adult hippocampal neurogenesis: a ...
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Action potential frequency presynaptic neuron comared with in post-synaptic neuron/ muscle cells

I am a physicist interested in knowing how the action potential frequency in a presynaptic neuron compares with that in a) a post-synaptic neuron and b) membrane depolarisation of muslce cells, ...
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Why do cyanide and arsenic smell like almonds and garlic, respectively?

Why do humans smell arsenic as garlic or cyanide as almonds? Do both smells activate the same receptor? Is there any reason why our brain interprets these smells the same?
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1answer
35 views

In Study from Blue Brain they say position of synapses doesn't change even if they modify neurons, only when they change shape of neuron it changes?

https://medicalxpress.com/news/2012-09-blue-brain-accurately-neurons.html We could vary density, position, orientation, and none of that changed the distribution of positions of the synapses..... ...
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1answer
153 views

What's the real meaning of “brain shrinkage”?

It is known that some pathologies cause brain shrinkage, for example, it is said that depression causes shrinkage in the hippocampus. My problem to understand the statement, is that I don't undestand ...
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1answer
74 views

Pitch perception - why is the missing fundamental not directly detected in the cochlea?

I'm learning about pitch perception, and learned about the case of the missing fundamental. In the main image in that wikipedia page, it seems like the bottom graph, with the fundamental frequency ...
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1answer
522 views

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 ...
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1answer
104 views

Can neurons take oxygen from air?

Why can't/don't neurons take up atmospheric oxygen or at-least dissolved oxygen (like amoeba does) to survive and do all life processes outside animal body ???
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1answer
429 views

Why is atropine a CNS stimulant, although it blocks the muscarinic receptors in the brain?

I know that atropine is a muscarinic antagonist, so why does atropine have excitatory actions on the brain while it is blocking muscarinic receptors?
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1answer
69 views

How are sound waves amplified while traveling within the cochlea?

How are sound waves amplified while traveling from the basal membrane to apical membrane within the cochlea? Are they amplified by the movement of the stapes?
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How does axon guidance system precisely targets specific axons?

Axons find their way to the terminus by responding to axon guidance molecules (AGMs) that attract and repel growth cones or make them stir. This I understand. Through a very specific combination of ...
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Can adenosine be cleared?

I've been thinking about this question for awhile, since reading this question: What causes adenosine build up in the brain when awake? We know that a couple of things will block adenosine receptors: ...
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2answers
6k views

What is in the space between neurons in a brain?

When neuron animations are displayed, there are frequently seen neurons, axons arranged in a lattice with a lot of empty space between. I'm interested if there is indeed empty space in the brain, or ...
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29 views

To what extent does the distribution of nerual transmiters in the brain vary human to human?

Suppose $x$ is a position in the brain, and $n_i(x)$ is the density of neuro recepter $i$ around that point. Any given human will have some distribution of neruo recepters $n_i(x)$ through out there ...
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1answer
11k views

Serotonin - Does being aroused make you sleepy?

My Psychology text book says Serotonin causes "Sleep, arousal levels and emotion" Does this really mean that when you are being aroused, Serotonin is released, which in turn makes you sleepy? If so, ...
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1answer
48 views

What happens in a nerve cell when a thought is generated?

I know basic nerve physiology of impulse conduction and transmission, but I don't know what actually happens in a nerve cell when a thought is generated. When a external stimulus (like tactile ...
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3answers
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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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2answers
764 views

Inductance in cell

In an animal cell, especially neuron and in particular its axon, while there is electrical resistance and capacitance mechanism in the cell, which play essential roles in the cable theory model of ...
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1answer
73 views

How does the brain fake itself into hearing our own sounds even when we are not speaking?

Typically When we are talking to our own selves at any time in the day,the Brain thinks that it's me who's speaking , how does it create illusion of speaking ?
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1answer
562 views

How can there not be purpose movement in the fetus until week 18, when a fetus can open its mouth and suck its fingers at week 11?

According to Fetal Movement According to an overview produced by the Royal College of Physicians of Edinburgh, purposive movement begins at about 18 weeks, gradually replacing reflex movements ...
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1answer
122 views

Why is peripheral vision not bleached by daylight?

In daylight, rods are known to be bleached: we have to wait some time after going into darkness before scotopic vision becomes effective. But, as I understand, peripheral vision is also mostly due to ...
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1answer
75 views

What physiological processes give rise to a linear cell survival curve?

If we plot the number of surviving cells in a structure over time (assuming no replacement), the shape of that curve should imply something about the underlying process responsible for cell death. For ...
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1answer
70 views

Are there humans which the brain sends signals to the limbs faster than the average?

I have done some researches on the time taken by the brain to send signals, but I didn't find whether that time is the same amongst all humans or there are some differences, and I have based my ...
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2answers
172 views

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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1answer
934 views

Is lumosity.com based on science?

I always see these Lumosity ads on TV, and I personally feel they are just trying to "sell me something". I did some layman's research (wikipedia) and read that "Studies of Lumosity's effectiveness ...
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2answers
37k views

How do the brain and nerves create electrical pulses?

The information between the brain and peripheral nerves is sent via electrical pulses or signals, How then does a non-metallic human cell manage to conduct an electrical signal?
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2answers
83 views

What is the mechanism behind the F-Wave?

Can someone explain the actual mechanism behind the F-wave? Is it really different from a H-reflex response or does it just have another name for historical reasons? The H-reflex (Hoffmann's reflex) ...
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1answer
166 views

What happens in a brain of a person suffering with apathy?

According to this article Apathy is a profound loss of motivation not attributed to decreased level of consciousness, cognitive impairment, or emotional distress. Apathy refers to a set of ...
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3answers
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What exactly is the time constant of an ion channel gating?

Let's take a channel that does not get inactivated, but is only in open and closed states. I understand what m (activation variable) represents. It's the fraction of the gates open. But what does $\...
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1answer
83 views

Causes of the stochastic behaviour of voltage-gated ion channels

I came up with the following electro-mechanical model of a voltage-gated ion channel, resp. of its voltage sensor as described here and here. The voltage sensor is a bistable system with two local ...
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2answers
37 views

How to determine if the amount of manganese chloride will change neural resting potential

If I am treating an organism in MnCl2 dissolved in water, how do I determine if the amount of Cl (in MnCl2) will change the neural resting potential Oor if it will influence motoneurons?
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Once neurotransmitters bind to its receptors, how does the post synaptic neuron “know” when to start a new action potential?

My textbook seems to gloss over this subject. Once the post-synaptic receptors are activated, do they cause particular ion channels to open, letting positive charge into the cell and inching the ...
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56 views

Does opening of ion channels alter the membrane potential directly?

Does the opening of a voltage-gated ion channel (i.e. the change of configuration of the protein) by an appropriate local change of the membrane potential directly and significantly alter the membrane ...
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1answer
45 views

Abrupt movements of birds and reptiles vs. smooth movements of mammals

How can it be explained (in evolutionary and/or neuronal terms), that the spontaneous movements of birds and reptiles are seemingly "abrupt" and not so "smooth": Their spontaneous movements seem to ...
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0answers
78 views

Can cognitive functioning of the human brain change the physical state of the brain? [closed]

Can cognitive functioning of the human brain change the physical state of the brain? E.g. does self-awareness, self-reflection change the number of neurons or synapses among neurons? I.e. I am trying ...
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1answer
44 views

Flow diversion for cerebral aneurysms or stabilizing the hemodynamics?

I'm doing research of flow diverter for cerebral aneurysms applications and I'm wondering the reason behind stent placement underneath of cerebral aneurysms is to divert the flow or stabilize the ...
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1answer
3k views

What is the “stimulus” that initially triggers an action potential?

There are many steps detailing the depolarization and repolarization of axon nodes to describe how an action potential is transmitted from a neuron. But, after looking at many different sources, I ...