Questions tagged [neuroscience]

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

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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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1answer
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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 ...
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Schematic of neural lineage tree and position of Choroid Plexus cells

I am trying to understand which are the different type of progenitors in the human brain and I am currently following this schematic. My question is, are Choroid Plexus cells progenitors to Radial ...
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1answer
26 views

What determines the influx of calcium ions in the voltage-gated ion channels?

Calcium channels play a crucial role in neuronal signaling by helping the synaptic vesicles to fuse through the synaptic active zone and release their neurotransmitters. My question is, at a given ...
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2answers
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Do human beings have pheromone receptors?

What is the current consensus on whether or not humans have receptors that detect pheromones? If there are purported receptors, in what anatomical areas are they located? With what organ systems do ...
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1answer
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If nerve consists of many axons, where are then their soma located?

This question has haunted me for two years. Wikipedia mentions : A nerve is an enclosed, cable-like bundle of axons (the long, slender projections of neurons) in the peripheral nervous system. A ...
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1answer
48 views

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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Breakdown of functional human genome by organ/What fraction of the functional human genome is devoted specifically to brain functioning?

Of course, there won't be a precise known answer to the question, as it is not even known precisely what percentage of the genome is functional in the first place - but I am still looking for research....
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Understanding the ECG waveform with respect to Lead Positions

I am really confused about the Representation of potential in an ECG graph. First i will ask what is on the vertical axis? (I guess it is electrical potential in millivolts) But again it changes for ...
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1answer
76 views

What is the function of dreaming? Does a particular hormone secretion interfere with dreaming? Why do some people dream more?

I'm really interested to know when we are sleeping how a series of stories come to our mind that we called this process dreaming. If you know a useful article on this topic, please tell me thanks.
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How do defibrillators work? [duplicate]

I've heard that defibrillators apply a certain voltage difference to the cardiac region and this temporarily inhibits the pacemaker. Can anyone please explain me how it works with respect to what ...
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1answer
112 views

Why do biologists judge intellect based on brain size?

I have seen many times, that scientists will say Species A is smarter than Species B due to a higher brain-to-body ratio. I've even seen similar arguments made by comparing the sizes of specific ...
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2answers
779 views

Can one become suddenly ambidextrous? [closed]

Is it possible to become ambidextrous? i'm 67 and recently and suddenly became ambidextrous about a month ago. I can write w both hands at the same time.
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1answer
36 views

What does microglia process length tell us?

I'm reading a study investigating traumatic brain injury and alcohol consumption and the researchers measured microglia process length as an indicator of brain damage. I was wondering what that would ...
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0answers
15 views

Has anyone attempted to add extra senses to a creature through a BCI/Neural interface?

Basic BCI's (Brain computer interfaces) have been available for quite a while now and allow users to preform rudimentary tasks such as moving prosthetic limbs with force-feedback or moving a mouse on ...
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0answers
53 views

Inhibitory functional connectivity

Functional connectivity may be defined as »the temporal correlation between spatially remote neurophysiological events, expressed as deviation from statistical independence across these events in ...
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2answers
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What is synaptic clearance?

Please explain what the term synaptic clearance means. For example, what would dopamine synaptic clearance be? It is important to me in context of dopamine signaling variation due to difference in ...
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1answer
4k views

How does a microelectrode work?

On Wikipedia, the entire microelectrode page states only the following: A microelectrode is an electrode of very small size, used in electrophysiology for either recording of neural signals or ...
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Is relative timing of signal transmission between neurons along axons and through synapses relevant in the brain?

A neuron may be part of a nerve connection between two endpoints, transferring a signal that is not very sensitive to variations in signal propagation speed. But a neuron inside a cluster of ...
5
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1answer
2k views

Can a lack of sleep degrade balance?

For years, I've noticed that the day after a night of poor sleep (4 hours or less), my balance noticeably degrades. For instance, while walking 20 feet to the coffee maker, I might stumble into the ...
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45 views

Long-term potentiations that last for a lifetime

One reads more often than not that long-term potentiation has been reported to last for as long as several weeks LTP is persistent, lasting from several minutes to many months and most sources seem ...
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1answer
77 views

Differences between neurotransmitters and neuromodulators

According to the Wikipedia article on neuromodulation a neuromodulator can be conceptualized as a neurotransmitter that is not reabsorbed by the pre-synaptic neuron or broken down into a ...
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1answer
54 views

Ion-gated ion channels

Today I've heard for the first time of calcium-gated ion channels but find it hard to get an idea how they work, where they are located, and which role they play. I assume calcium-gated ion channels ...
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1answer
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How precisely can we sense temperature differences?

We have thermoreceptors, thus we can sense temperature (both warm and cold). I'm interested in the sensitivity of our thermoreceptors - What is the smallest temperature difference that we can sense? ...
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1answer
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Looking for books on How the limbic system works and it role in non-verbal behavior

This is my first post. I just read and I'm currently studying a book called "How everybody works" as a guide to understanding nonverbal behaviors. After I'm done studying it and while I experiment ...
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1answer
42 views

To what extent does loss of neurons in the substantia nigra affect movement?

There is a substance known as MPTP that is capable of crossing the blood-brain barrier. Once it does so, it is metabolized into a toxin called MPP+, which then selectively destroys dopaminergic ...
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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 ...
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1answer
77 views

Parts of the brain pivotal for maintaining consciousness

From an answer to another question (on conscious experiences by coma patients) I have learned that no conscious experiences, complex thoughts, or complex emotions can occur when one is in coma (...
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1answer
109 views

How does the dopamine spike from drugs compare quantitatively to pleasurable non-drug activities?

I did find this popular press article that quotes a researcher offering the following quantification: "in lab experiments done on animals, sex causes dopamine levels to jump from 100 to 200 units, and ...
2
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2answers
53 views

How are presynaptic burst firing signals transmitted post-synaptically?

Neurons can exhibit burst firing and this presynaptic process basically results in a flurry of action potentials being fired in a short time window. I'm, however, wondering how these signals are ...
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Functional roles of firing patterns

Eugene Izhikevich reports – e.g. here – a plethora of neural firing patterns: My question is two-fold: Is there an overview which types of neurons are capable of (and typically exhibit) ...
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1answer
65 views

What are the disadvantages of myelin

The myelination of axons has plenty of advantages. It increases signal speed in axons, and thereby reduces reaction times. This is, of course, very good for the survival of the animal in question. ...
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1answer
505 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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0answers
146 views

How optimal are the distances of voltage-gated ion channels on axons?

In both myelinated and not-myelinated axon segments ("axons" for short) there are theoretically maximal distances of voltage-gated ion channels beyond which propagation of the action potential would ...
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2answers
61 views

Number of dopaminergic neurons in VTA

Do you know an authoritative source for the approximate number of dopaminergc cells in the ventral tegmental area (VTA)? Ideally I would like to know this for mice, rats, as well as humans, but one ...
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1answer
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What is the meaning of depth relation and EM in this excerpt?

In the excerpt below from Morphology of Invertebrate Neurons and Synapses For the better part of a century, conclusions were made largely by matching the depth relations between the terminals of ...
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1answer
31 views

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 ...
3
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1answer
42 views

What makes synaptic vesicle release probabilistic?

The fusion of synaptic vesicles (SVs) with the plasma membrane of the active zone (AZ) upon arrival of an action potential (AP) at the presynaptic compartment is a tightly regulated probabilistic ...
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1answer
44 views

Vision: what is the difference between on-off ganglion cells and lateral inhibition?

Is 'lateral inhibition' just a term for the biological basis of the functioning of the on-center (or off-center) ganglion cells? Or do these terms describe separate processes?
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1answer
35 views

Neuron stimulation experiments

Has anyone extracted a class of neurons (or a connected set of neurons) and stimulated them electrically to get an understanding of their behavior? If so, could someone point me to papers along these ...
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2answers
1k views

Special visceral efferent

Why are special visceral efferent nerves are named as such? They are supplying motor impulses to muscles of pharyngeal arch, which are both skeletal(facial) and visceral(laryngeal) 1, so why only ...
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2answers
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 ...
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1answer
135 views

How fast do we fall asleep?

When looking at the process of sleeping, most research I find point to a group of mutually inhibitory cells which form a sort of biological "flip flop." There's cells that promote awakenness and ...
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1answer
553 views

Does a generator potential pass along a nerve the same way an action potential does?

I have read that a generator potential is a localized depolarization of a membrane. Does that mean that it does not pass along a neuron the same way an action potential does ? If not, then how do ...
3
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1answer
160 views

Reward pathway sequence of events

So I've been reading a lot of papers on the reward pathway. But since I'm not schooled in any relevant knowledge I'm having trouble grasping the chain of events. Most papers detail just bits and ...
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3answers
1k views

How can an animal live without a head / brain?

The human body is unable to do anything if it loses its head - as the brain is separated from the body, the body immediately dies. But why does the same not happen to other species or animals? (As ...
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1answer
65 views

How is the electrical potential difference distributed between two stimulating electrodes?

Suppose I set the voltage value of an isolated stimulator with a floating ground. I place one electrode above the spinal cord (positive) and the other placed subcutaneously far away from the spinal ...
5
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1answer
145 views

Where can I find a diagram of cortex connections?

Has anyone come across a diagram (2D, 3D, maybe even interactive) of the connectiontions between cortex regions? Especially, the diagram should display the strength and direction of those connections (...
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2answers
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Do ants feel pain?

I have watched video on youtube where guy pours molten aluminium into fire ant colony to make casing. In the comments below there's huge discussion on is that a right thing to do. I am on the side ...
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Can brain activity be restored after being stopped, assuming no cellular damage?

I was reading about cryonic preservation recently. In a separate place on the Internet, I've read that once brain activity stops and brain death occurs, the person is dead with no hope of recovery. ...

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