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

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Can neuron change from excitatory to inhibitory (end vice versa) over time?

According to this answer a neuron can release only specific type of neurotransmitters at the time, however, could it change over time? For example a neuron that now releases only inhibitory ...
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14 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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14 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 ...
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1answer
33 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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19 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?
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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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1answer
19 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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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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1answer
205 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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18 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 ...
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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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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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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 ...
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27 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 ...
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2answers
124 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 ...
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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 ...
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1answer
58 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 ...
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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 ...
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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
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?
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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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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
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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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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2answers
103 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 ...
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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
32 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 ...
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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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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 ...
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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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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, ...
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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
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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 ...
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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 ...
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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
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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?
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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, ...
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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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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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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 ...
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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 ...
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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 ...
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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 ...
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1answer
30 views

How large is a neurotransmitter? Max and min sizes?

What size(s) are neurotransmitters? What is their size relative to the synaptic cleft? Relatively speaking, can we tell how far they must travel to cross the gap? Twice their own length? More? I ...
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0answers
12 views

Is there a disorder that causes one to feel heat from an inanimate object?

We just met a woman that feels heat (literally, hot enough for her to say she was burned) from inanimate objects. She says it is mainly the floors and chairs in her home, and she is unable to walk in ...
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2answers
62 views

How useful are neural circuits in psychology?

We can identify many kinds of patterns of how neurons connect such as lateral inhibition, negative/positive feedback, convergence, divergence, and facilitation. But have any of these circuits been ...
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1answer
33 views

Is there any way to calculate the cumulative width of synaptic clefts?

It's my understanding there are 150 trillion synapses in the human brain (give or take). Is there a way to calculate the cumulative width of all synaptic clefts associated with the synapses? I would ...
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Where can I find good references about the neuronal connections in various areas in the cortex?

As an example, I would like to know which Brodmann areas the layer IV in area 10 receives input from. To which degree are these connections known? What are good books or other kinds of resources that ...
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1answer
33 views

What are the estimates in total neurons and average connections per neuron for each of the processing areas of the visual cortex?

I am trying to find ballpark estimates for the number of neurons in each functional area of the visual cortex (V1, V2, V3, etc). While nice if known, the numbers themselves are not as important to me ...
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4answers
230 views

Is it possible to increase the capacity of human brain like “Lucy”?

I saw the film "Lucy" in 2015. The film says that humans can use 100% percent of the capacity of their brains. According to my personal ideas, the capacity of the brain will changed based on the ...