For questions about the biology of the nervous system, from a macroscopic to microscopic perspective.

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1answer
26 views

Can one neuron spike inhibit and excite at the same time?

Is it possible to have a neuron that in some synapses releases inhibitory neurotransmitters and excitatory in others (everything triggered by the same spike) ?
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0answers
11 views

A state model of sodium channels

I am studying by myself Human Physiology. I have encountered the following question: In the following given model of sodium channel with 3 states open closed blocked (which I assume means ...
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1answer
36 views

What prevents a neuron from activating an incoming synapse?

As is known, a neuron can have incoming and outgoing synapses. When a neuron fires, what does prevent that only outgoing synapses are activated?
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5answers
23k views

Why would the brain flip the images perceived by your eyes?

The following is a common scientific statement, which you don't have to google long for to find: The eye views images upside-down in the manner of a camera lens, but our brains reinterpret this ...
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0answers
12 views

Voltage sensitive dyes technique: 2-photons microscopy vs confocal microscopy

I just discovered voltage sensitive dyes technique and I was wondering what would be the advantage to use 2-photons microscopy compared to confocal microscopy? They are both fluorescent techniques ...
2
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1answer
14 views

Voltage sensitive dyes technique: What is the underlying measure?

I just discovered voltage sensitive dyes technique: I have seen that figures are labelled with dF/F0, what does it stands for?
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0answers
16 views

Can a neuron fire when hyperpolarized?

Is there any chance that a neuron could fire when hyperpolarized? In that case the spike would probably be different than usual?
9
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1answer
148 views

Do all types of synapses in the brain change based on spike-timing-dependent plasticity?

Synapses likely change their strengths based on a form of spike-timing-dependent plasticity. Is this true for all types of synapses in all parts of the human brain? I wonder if there are also synapses ...
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2answers
23k views

Why are some people unable to easily memorize the lyrics to a song?

Although I have listened some songs hundred of times I can't sing the lyrics to any of these songs from beginning to end without pauses. However I am able to whistle the whole song without difficulty. ...
3
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1answer
201 views

Does the human visual system implement (adaptive) histogram equalization?

The human visual system is very good at 'cancelling out' shadows and other lightning effects, and focusing on the contrast in images. A famous example of this is Adelson's checker shadow illusion: ...
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0answers
18 views

Analysing ERP (Event-Related Potentials from EEG recordings in fucus on P-300 waves

I am trying to understand how to analyze ERP (Event-Related Potentials) from EEG recordings in fucus on P-300 waves. I have come up with a few questions which I hope you might be able to help with: ...
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0answers
17 views

Which brain structure or function cannot be studied using neuroimaging techniques?

Considering CT, PET, MRI, fMRI, EEG, MEG, DWI, and DTI techniques, is there any structure or function of the brain that cannot be determined and studied using regular imaging techniques? My first ...
8
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2answers
7k views

Which neurotransmitters can be measured in a living human brain?

I'm interested in learning more about the modern techniques that are used for scientific studies of neurotransmitters in the living human brain. As far as I know, there are 4 neuromodulator systems ...
4
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1answer
47 views

Is the ordering of Brodmann areas arbitrary?

A single Brodmann area is defined based off cellular composition. Are the Brodmann areas ordinal, and if so for what reason? (e.g. is there something that makes Brodmann area 1 the "first one", and ...
3
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1answer
49 views

Do dissolving myelinated connections explain learning?

In order to understand how we get rid of established habits/behavior: Can myelinated connections be dissolved or are new connections created that bypass those connections?
3
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0answers
26 views

How does the hippocampus and the “Papez” circuit form a memory?

It is admitted the hippocampus is necessary to the formation of new long term memories. At first, information goes back and forth between various parts of the cortex and the hippocampus. That's how a ...
4
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0answers
20 views

Does testosterone level cause more sexual dream content?

I have long been interested in dreaming, including how dream content can shed some light on brain chemistry. I did a search on the subject of testosterone levels altering dream content and see some ...
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0answers
10 views

The number of dendrites versus axon terminals

Refer to this answer, I know there are thousands of dendrites make thousands connections, and only multiple axon terminals. Normally, connections (synapse) are classical axon-dendritic synapses which ...
6
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2answers
123 views

Does electricity pass through synapse?

As far as I understand, when a neuron fires the action potential generated in a cell body reaches only the presynaptic part of the synapse, then triggers the transmitter to pass through the gap, and ...
6
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0answers
35 views

Does the brain generate identical words in different languages similarly?

Saying (or even just thinking) a word or phrase results from activity in multiple regions of your brain. Of course, we can measure/'map' this activity to some degree; From wikipedia: EEG measures ...
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1answer
41 views

Is the amount of learning modulated by reward transmitters?

The human brain is a signal processing system. Input streams contain sensory, motor, reward and possibly more signals mixed. I wonder if neuro transmitters associated with reward increase or decrease ...
5
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1answer
57 views

How / when does neurogenesis occur while learning?

I've heard that learning to Juggle (new things) helps increase neurogenesis. So, what does it depend on? Does it have to be a physical skill only? Or can I study / read about Economics(which is ...
0
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1answer
19 views

Do gating mechanisms in the neocortex have individual degrees for all gated connections?

For example, the upward connection between layers in the neocortex flows through the Thalamus which is assumed to have a gating function. I wonder whether there is a single value per gate, ...
2
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4answers
90 views

What are the rules that govern neuron behavior?

This is what I know so far: Neurons are nodes with a number called the threshold. Neurons are connected to other neurons through directed axons. Axons take the signals produced by neurons and ...
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0answers
28 views

Which hormones are known to cause which psychological effects?

This might be a very broad question, but I'm looking for gathering a list of any hormone that can cause psychological effects - especially long-term. I would like to build a list of psychological ...
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0answers
37 views

How common is it for twins conjoined at the head to share thoughts and visual stimuli?

I've always been interested in the possibility of a pair of conjoined twins, joined at the head, being able to read each other's thoughts, react to stimuli that one of them can't see/hear/feel, and ...
5
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1answer
72 views

How far can a signal travel in the neocortex without passing through the white matter?

Correct me if I am wrong please, from what I understand horizontal communication spans very short distance in all layers of the neocortex but layers I and II. In these two layers dendrites and axons ...
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1answer
42 views

How long does a spiking signal last?

It is surprisingly hard to find information about the timing of neurons, in particular how long an action potential can contribute to the summation of a neuron. Is it on the order of milliseconds or ...
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0answers
20 views

What is the role of non-synaptic plasticity in learning and memory?

Is non-synaptic plasticity (e.g. changes in the spike threshold) believed to play a large role in learning and memory? If so, which roles are these effects believed to play?
3
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1answer
29 views

Publicly Available NEURON models

NEURON is a software package for simulating neurons and networks in great detail. Although it's quite easy to find papers that use NEURON with a simple Google Scholar search, is there some way to find ...
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2answers
102 views

If orgasm triggers bonding and feelings of love, why don't people continue to stay in love?

I am a bit confused by the effects of orgasm in bonding; everything I seem to read seems to be a bit careless with the truth and does not mention why people fall out of love or why people who are in ...
0
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2answers
39 views

What causes dopamine in our body [closed]

I was curious as to know what are the natural causes for the secretion of dopamine in our body. Are there any specific foods that increases the dopamine level? It is said that dopamine are usually ...
4
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1answer
87 views

When does reward occur? When dopamine is released or when it is binded?

I know this is a silly question, but I'm curious as to what is the exact phase when we experience of the thrill of doing an exciting activity. I believe this briefly describes the whole process. So, ...
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1answer
30 views

What is input resistance and how to interpret its values?

For example, this site gives a distribution of values of the input resistance of various cells. The values are in MOhms. The definition says that "input resistance measured at steady-state voltage ...
2
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1answer
46 views

During synchronized waves oscillation (alpha beta etc…) do neurons fire only once for each wave cycle?

Or can they fire few times then pause and again, firefew times and pause periodically? If the second case happens then do we know if the neurons that fire in synchronity fire the same number of ...
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0answers
27 views

When we say signals go from one cortical area to an other one do we mean they go directly without going through the thalamus for example?

Or is it implied signals always have to go back and forth between the thalamus and the cortex? Or is it possible they do both at the same time? Or maybe for areas next to each others they can go ...
6
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2answers
97 views

How would the blind experience a hallucinogen like LSD?

I have heard that LSD allows you to see ridiculous things. But they are things that you have seen, or can imagine to see. If you've never seen before (like a blind person), what effect will LSD have ...
4
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2answers
50 views

Are there specific neurotransmitters for specific sensations?

Nerves can detect pressure, temperature, light (eyes), sound, friction- at least. Does each sensation have its own neurotransmitter? I'm only a little familiar with neurotransmitters. This page ...
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0answers
40 views

Infants tend to look longer at novel stimuli than at repeated stimuli, is this true in adults?

I have recently read an article in which it is stated, that the researchers can discriminate if a baby knows an object, by looking at the length of time the baby looks at the object. Do adults also ...
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0answers
10 views

How can higher concepts get unrolled with upward and feedback connections differing?

In the neocortex, input patterns are compressed hierarchically. Sensory inputs in the lower levels are combined by higher levels to form abstract concepts. However, there are even more feedback ...
0
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1answer
21 views

Is k-winner a biological plausible model of inhibition?

In the Leabra cognitive architecture, sparse representations are created by simply ignoring all but the k strongest activations, if I understand correctly. In Hierarchical Temporal Memory, instead, ...
0
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1answer
47 views

Is the heart conscious?

I have read that our heart can think like our brain. Of course it doesn't have complete functionality of brain but it has its own consciousness. Is it true?
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3answers
89 views

Which parts of the brain are affected by dopamine?

Does dopamine spread and interact across the whole brain? If not, which areas are affected most and which least?
0
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1answer
21 views

How do neuro transmitters interact with neurons in the brain?

I think emotions and hormones frames the overall thinking processes of the brain. However, I'm interested in how this works on a neuronal level. For example, dopamine is some kind of reward signal for ...
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0answers
13 views

what is the exact definition of a receptive field ?

i have read the wikipedia article on receptive fields . the article defines a receptive field as The receptive field of an individual sensory neuron is the particular region of the sensory space ...
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0answers
15 views

location of the center surround receptive fields for retinal ganglion cells

i have read wikipedia article about receptive fields of visual system . it says The receptive field is often identified as the region of the retina where the action of light alters the firing of ...
3
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1answer
118 views

Threshold time for stimulus to be consciously perceived. Why?

A visual stimulus must last longer than some threshold duration to be perceived consciously. For example, a light dot flashed for a duration of 10ms can't be consciously perceived. Why? What prevents ...
3
votes
1answer
60 views

Can two neurons in the brain be connected more then once?

Can two given neurons in the human brain can be directly connected more than once, either mutually or in the same or direction? Also, can the same neuron have transitive connections to itself (in ...
8
votes
2answers
362 views

What computerized EEG analysis algorithms are there?

I got a commercial-grade EEG headband and am trying to look at the data it outputs. The headband quantifies raw EEG signal from a single forehead dry sensor into a range of EEG bands (alpha, beta, ...
4
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2answers
98 views

Are axons in the brain weighted?

Is it known whether the connection strength of synapses is important to the functioning of the brain or does just the binary existence of a synapse matter? Also, how widely do the strengths of ...