Questions tagged [neuroscience]
The study of the structure and function of the nervous system and its components.
1,163
questions
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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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0answers
19 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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0answers
12 views
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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0answers
15 views
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
61 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
86 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 ...
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34 views
How can I apply a PhD in biology without a science academic background? [closed]
I want to apply a PhD in biology related subjects, e.g.: neuroscience, biochemistry... But I don't have a science academic background. What should I do?
I have 3 years working experience in ...
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1answer
52 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
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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
34 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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0answers
26 views
Neural circuits and choices
As many know, the brain consists of a circuit made of neurons, which, I think, are interneurons because the brain is a part of the CNS (Central Nervous System). However, are these neurons involved in ...
2
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1answer
41 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?
2
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1answer
38 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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47 views
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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1answer
38 views
Factors behind frequency of action potential
I understand that the amplitude of an action potential is not influenced by the strength of the stimulus. I also understand that the perception of the strength of the stimulus depends on the frequency ...
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2answers
77 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 ...
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1answer
27 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 ...
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1answer
50 views
Does the cranial dura consist of the periosteum? and if not, then is there a mistake in my textbook?
My textbook (Neuroanatomy an illustrated colour text) states that:
The spinal dura and much of the cranial dura are separate from the periosteum, which forms the inner lining of the surrounding ...
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0answers
30 views
Can IPSPs produce an action potential?
This picture was taken from Purves' Neuroscience, chapter 5:
Image (C) shows a inhibitory postsynaptic potential whose reversal potential "goes" to the action potential. If two or more IPSPs occur, ...
11
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1answer
132 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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0answers
19 views
What are the chemicals in the gap at a synapse? [duplicate]
I am learning about (introductory level) biological psychology and the synapse structure came into mind. I do understand that neurotransmitters are transmitted between two neurons via the synapse ...
2
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1answer
56 views
Why/how does exposure to noise cause cochlear hair-cell loss?
I am trying to understand why listening to loud music - e.g. concerts or earphones at high volume damages hearing.
According to the National Institute on Deafness the cause is physical.
Most ...
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0answers
19 views
What is the purpose of descending auditory signals from the brain?
What might the purpose be of the brain having descending auditory signals from the brain? My textbook is very vague about this and I am just curious.
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What are the advantages of bidirectional signalling in electrical synapses?
Electrical synapses are known for being very fast at communicating with other neurons. (1)
What I often see in articles about electrical synapses is that they are bidirectional.(1) This is seen as a ...
2
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1answer
106 views
Is sexual desire stronger in men than women?
Usually in popular culture it's considered men sexual desire is stronger than women. This seems to be congruent with the availability of sexual related items for men and women, such as magazines, ...
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0answers
51 views
Why is there no solid evidence (histological, fMRI) that the vestibular hair cells of the inner ear contribute to 53% of the respiratory drive?
There are these papers which strongly imply that the inner ear hair cells, and not the medulla, is primarily the driving factor in the CO2 drive reflex
https://www.ncbi.nlm.nih.gov/pubmed/21130842
...
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1answer
18 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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1answer
24 views
What happens when the conductance of a sodium channel increases?
My intuition is that, since the concentration of sodium within a cell is higher than the extracellular concentration, when conductance increases, this corresponds to the channel being open and means ...
2
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2answers
64 views
Are neurotransmitters part of the endocrine system?
I was speaking with a substitute teacher of mine, and we were discussing whether neurotransmitters are part of the endocrine system or not. My class just spent an entire semester on the topic of the ...
2
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1answer
56 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 ...
19
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2answers
4k views
What makes learning more difficult as we age?
Why is it harder to adapt yourself to different cultures, places, and languages as you age? What makes breaking up with emotional patterns or ideas after years of habit more difficult?
Is there a ...
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1answer
16 views
Do astrocytes connect and chemically communicate with other astrocytes?
I am building a novel model of neural tissue for the purposes of Machine Learning and am currently trying to unpick the functions of the astroglia.
The literature suggests that astrocytes ensheath ...
0
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1answer
30 views
A question about how the brain determines the source of a sound
If a person's eardrum vibrates, let's say, 440 times per second for 1 second, how does the brain know its because 1 sound source vibrated 440 times, as opposed to 440 sources vibrating once, one after ...
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1answer
18 views
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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28 views
Is there a minimum amount a muscle can move? And thus, gaps in our movement?
Lately I've been thinking about something, based on my knowledge my chain of reasoning works like this...
When you want to move a muscle your brain sends an electrical nervous impulse along the chain ...
4
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1answer
57 views
What makes synapses stay “fixed”?
What makes synapses not move or pre- and postsynaptic cells neither touch nor move away from each other? I mean the synaptic cleft is a gap between the pre- and postsynaptic cells that is about 20 nm ...
2
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1answer
33 views
can auditory/ocular reflexes exist?
In the same way the knee-jerk reflex is a thing (I think the nerve signal doesn't go through the brain?), can stimuli received by the eyes or ears trigger "instantaneous" (faster than the brain can ...
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32 views
Can we “learn” reflexes?
Can we force our bodies to react to situations faster than our brain can think about them?
Some reflexes I can think of off the top of my head:
knee jerk reflex
retracting hand when touching a hot ...
3
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1answer
47 views
How do we know if a neuron is inhibitory or excitatory?
The textbook examples for an excitatory neurotransmitter is Glutamate, and for an inhibitory neurotransmitter it is GABA.
In my naive understanding, a neuron was inhibitory or excitatory depending on ...
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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3answers
100 views
Could we have endless pleasure?
Are there any studies that point out that we could have a device in the future or drug that could give us endless amount of pleasure by stimulating or blocking processes in the brain or nerve system? ...
3
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1answer
69 views
What is the basis of the endocochlear potential?
I am learning about the endocochlear potential. According to different sources, the ionic composition of perilymph is about as follows (in mM): 150 Na+, 4-5 K+, 1.2 Ca2+, 1 Mg2+, 120 Cl−, and 20 HCO3−;...
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17 views
Does the prefrontal cortex fold over the diencephalon (limbic lobe) during embryogenesis?
The frontal lobe as the top of the vertebrate brain, does it fold over the diencephalon during embryogenesis and development of the brain?
3
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1answer
84 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:
...
3
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1answer
89 views
What are these two nerves running parallel to the spine called?
I was looking for a human body nervous system, and often times i found a picture like the one below, where there are two nerves running parallel to the spinal column. I searched for it, but nothing ...
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2answers
107 views
Understanding the “Waterfall Illusion”
Motion after-effect illusions, such as the waterfall illusion, refer to illusions where fixating a screen which shows stimuli moving in a particular direction elicits the perception of motion in the ...
2
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1answer
41 views
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 ...
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1answer
31 views
Changes of permeability and driving force during voltage clamp
An action potential can be understood in terms of voltage changes, and these are fundamentally a function of relative permeability changes, mostly for Sodium and Potassium ions. If for instance the ...
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Is it possible to have action potentials in cells lacking both dendrites and axons?
I'm reading Kandel. Chapter 3 states the following:
Because the initial segment of the axon has the highest density of voltage-sensitive Na+ channels and therefore the lowest threshold for ...
3
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1answer
96 views
Cerebral/Cerebellar Cortex versus Deep Nuclei
I have troubles using the terms Cortex & Deep Nuclei, and 'Nuclei' in general. From what I understand, a brain has '3 matter types in accordance to anatomical locations'
Superficial Grey matter - ...
