Questions tagged [neuroscience]

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

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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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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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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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66 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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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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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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24 views

Can lead field be a scalar field? [closed]

In electrophysiology it is common to use lead (vector) field to describe relation between electric activity described as an electric dipole and the potential measured at electrodes. Can the term "...
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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, ...
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118 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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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 ...
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55 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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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 ...
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95 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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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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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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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 ...
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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 ...
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51 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 ...
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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
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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 ...
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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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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 ...
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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 ...
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32 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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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 ...
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46 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 ...
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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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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? ...
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68 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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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?
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82 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: ...
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1answer
79 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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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 ...
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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
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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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43 views

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 ...
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1answer
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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 - ...
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How long does it take the neurotransmitters to diffuse accross the synaptic cleft?

Neurotransmitters get from the pre-synaptic neuron to the receptors on the post-synaptic neuron by diffusion across the gap between these two (the synaptic cleft). My question is, how much time does ...
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Congenital deafness: can cochlear implants always improve hearing at any age?

People with congenital deafness may acquire a cochlear implant at a later age and be able to hear. Given that it seems there is a curve for synaptic plasticity of different circuits: (1) Cochlear ...
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104 views

What material fills the synaptic cleft? Is it water?

The synaptic cleft is the gap between the pre-synaptic and post-synaptic neurons, and neurotransmitters are transferred between the neurons within this region. What substance exits in this space, is ...
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How do cone cells underneath capillaries receive light?

Came across this image of retina's cross section: 1) How do the cone cells directly underneath the blood vessel ('demarcated in the picture') receive a spectrally correct representation of the ...
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Partial muscle fibre contraction

I'm being taught that: a muscle fibre spans the entire length of the muscle, from the originating tendon to the inserting tendon. The question is, can a muscle fibre contract only partially? Say, if ...
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Is there a maximum testosterone limit, or is it more accurate to say use?

I am constantly amazed at how we cannot differentiate between male and female. The International Olympic committee sets the target testosterone at 5 nmol per deciliter with active androgen receptors. ...
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Why does an increase in extracellular Sodium concentration increases action potential amplitude?

The title says it - I wonder why an increase in extracellular Sodium (Na+) concentration increases action potential amplitude? What I understand: I understand that an influx of positively charged Na+...
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23 views

The role of voltage-gated ion channels in chemical synapses

I am trying to understand the mechanisms underlying action potential generation on the cellular level. Typically, there is an emphasis on voltage-dependent permeability changes of Potassium (K+) and ...
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23 views

How are humanized antibodies made?

What kind of antigen is used to provoke/induce an immune response if you are trying to make therapeutic humanized antibodies for cancer and alzheimer's disease? For example, if you wanted to make an ...
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1answer
56 views

What differentiates neurons in different parts of the brain?

For example: what makes a neuron in the hippocampus of the brain different from a neuron in, say, the amygdala, or the frontal lobe, or anywhere else in the brain? Do neurons in different parts of the ...
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What trajectory do action potentials take, from initial visual stimulus all the way to motor function?

Say we see a mosquito, and our brain tells us 'hey that's a mosquito, you should kill it.' Then we move our hands and slap/clap it. The initial visual stimulus is translated to an action potential ...