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

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253 views

Do taller people have larger somatosensory cortices than short people?

When we assume that peripheral touch receptor densities are equal in tall and short people, then tall people should have more touch receptors than short people, given the larger amount of skin surface ...
8
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1answer
1k views

Why does it hurt more when you touch a nerve directly?

I am not a biologist nor know much about biology (so please explain in layman's terms) however I have always been curious as to why this is. What causes the difference in pain between touching an ...
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1answer
54 views

What could cause no pain but sense of touch?

What could cause a mammal to have and respond to a sense of touch with only isolated numbness but not feel pain?
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2answers
97 views

Is numbness the absence of one or all touch sensations?

I am studying the effects of tetrodotoxin and its symptoms when consumed. Numbness is one of the first sensations reported. But I googled numbness and I couldn't find information about whether this ...
4
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2answers
80 views

How does valerian make you calmer?

Why do Valerian pills make us calmer? What is the mechanism behind it? I understand how artificial tranquilizers work. Do valerian pill have similar chemical components?
2
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1answer
137 views

Biological implementation of convolutional neural networks

In computer science, 'convolutional neural networks' are used, that are meant to be inspired by biological network structures like found in the human brain visual cortex. In the computer ...
3
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1answer
72 views

Can the dendrites of sensory neurons be a meter long?

The typical textbook structure of neurons is a cell with a short dendritic tree and a long axon. The dendrites receive information and send it to the axon via the cell body (soma). The axon is a long ...
2
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1answer
36 views

How are physiological reversal potentials (or ion concentrations) of neurons measured?

Patch clamp electrophysiology experiments typically use an intracellular solution that mimics the ionic concentrations of neuronal cytosol. At the same time, the extracellular solution is meant to ...
2
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1answer
48 views

What's the explanation for those shivers/shudders that happen at random times? [closed]

They happen at any time, presenting as a sudden urge to shiver/shudder all at once. It originates in the neck and shoulders, feels like instant gooosebumps then out of total reflex shoulders roll back ...
3
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1answer
58 views

Development and function of spindle neurons

In his book How to Create a Mind author Ray Kurzweil makes some claims about spindle neurons that he provides no source for. Concretely he states that spindle cells: Are Involved in handling ...
3
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0answers
32 views

What is an extinction test?

In Stolerman & Olufsen (2001) I read the sentence: After drug-appropriate responding with the training mixtures reached 85%, generalisation to ethanol was examined in extinction tests. ...
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0answers
13 views

How do the connections from V1 to V2 form during early development of the human brain?

I am wondering how corticocortical efferents from layer I and II in V1 develop to forward visual information to layer IV in V2. Is there topology preservation in these connections from the beginning ...
3
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1answer
14 views

Is the thecal sac ectoderm?

The thecal sac, or dural sac, is the membranous sheath of dura mater that surrounds the spinal cord and the cauda equina. The thecal sac contains the cerebrospinal fluid in which the spinal cord ...
3
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1answer
22 views

How can dopamine modulate synaptic strength?

Does dopamine act on G protein coupled receptor, leading to more Ca2+ channels on the postsynaptic knob? Also, how is the specificity of the location (of the brain) that dopamine acts on controlled? ...
23
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5answers
12k views

Why do the two hemispheres of the brain control the opposite sides of the body?

Why does the left hemisphere control the right and the right hemisphere control the left? I googled it but didn't find a good answer regarding this. Could someone explain? Does this adaptation help ...
5
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1answer
52 views

Definition of general anesthesia

To quote Goodman & Gilman : An alternative way of defining the anesthetic state is to consider it as a collection of “component” changes in behavior or perception. The components of the ...
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1answer
31 views

Are axons capable of endocytosis?

There is evidence for the uptake of toxic substances like prions from the cell bodies of neurons via endocytosis. There is also evidence for prion deposition in white matter. But I haven't been able ...
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2answers
91 views

Why we shiver/tremble/shake while performing some work which requires high accuracy?

Shivering when nervous or anxious is a common thing. But, shivering or trembling sometimes also occurs when we are performing a work which requires high accuracy. In such case, our whole body doesn't ...
2
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0answers
55 views

I get regularly get déjà vu - but I know it's not a memory recall - I always think it's from a dream [closed]

My apologies if this is not the right forum for a neuroscientific/psychological question, especially not one coming from personal experience. Please close/move as appropriate :) Doubtless we're all ...
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2answers
65 views

Metabolic activity postmortem

I read some papers about studies on metabolism in post-mortem tissues in human, but I do not exactly the reason about why our brain continues to have activity after death.
4
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1answer
55 views

Do repetitive movements on EEGs show up as discernible patterns?

Here is a typical EEG reading: If I am connected to an EEG, and am sitting perfectly still, and then begin doing some repetitive motion, say, 10,000 times, will we see discernible patterns emerge ...
4
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1answer
144 views

What are dreams, biologically?

Falling asleep or states of subconsciousness does not stop the mind from making its own fictional images. These seem like sensations just like those received from human eyes. But, how do we define ...
7
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1answer
226 views

How is color information transmitted from the eye to the brain?

Is color information sent from the eye to the brain frequency-modulated, or are different colors transmitted by different axons? I know that each ganglion cell is connected to multiple ...
5
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1answer
108 views

Criteria for compound action potential thresholds

As opposed to action potential thresholds (which are binary yes/no events), electrophysiological thresholds of compound action potentials are arbitrary. Mostly a certain noise level is picked and when ...
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2answers
173 views

What will happen if we expose the brain to intermittent light?

If a brain is exposed to an intermittent light source, are specific areas going to fire? If yes, which of them? Is there a experimental data about this effect?
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0answers
68 views

What causes the range of severity of neurological deficits in Down's syndrome?

It's known that the severity of symptoms caused by a trisomy 21 varies from individual to individual. Part of the explanation for this range of severity is the finding that 94% of Down's syndrome ...
4
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2answers
143 views

Brain wave and motor movement correlation

I am trying to better understand which brain waves are generated when the motor system (arms, legs, muscles of any kind) are activated. According to Wikipedia, several types (Beta, Gamma, Mu) appear ...
3
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2answers
227 views

Confusion about resting membrane potential and the Na/K pump [duplicate]

To this day, very few people and sources have been able to clear up my confusion about resting membrane potential and how it is maintained. It seems like this is one of those topics that few people ...
3
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3answers
57 views

Resting membrane potential: K+ concentrations and charges on inside and outside of the neuron

According to this site, there is a greater concentration of K+ ions inside the cell than outside. The following screenshot, taken from this website, supports this statement. However, I don't ...
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21 views

Why is the autonomic nervous system divided into parts? [closed]

Why would it be advantageous from an evolutionary perspective to develop parasympathetic and sympathetic systems?
5
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0answers
50 views

What is the reason for fear induced defecation?

I started to handle mice for my job and noticed that they tend to defecate and/or urinate when they are scared. The fear is induced by me, because I need a long time (due to inexperience) to grab the ...
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7answers
5k views

Why can't we see in low light if staring long enough?

For me it seems reasonable that if I kept my gaze on a fixed point in a room with low light, a progressively brighter and better picture would appear before my eyes, just like a camera can see in the ...
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2answers
53 views

How does the mechanism which controls blood pressure in the brain work? [closed]

I've heard that the blood pressure in the brain is organised by a special mechanism. What is that and how does it work?
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1answer
92 views

Synaptic pruning and selective elimination during adolescence

How does Synaptic pruning occur during pre-adolescence, adolescence and post-adolescence, after there is blooming overproduction of synaptic connections until the years of late childhood, and how does ...
3
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1answer
89 views

What is the role of the tissue surrounding neurons in decision making and taking control of impulses?

How does the fatty tissue surrounding neurons supports and enhances the speed of electrical impulses? How does it stabilize connections that take control of impulses and decision-making? The cells ...
2
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1answer
40 views

What kind of changes “stays” in the neuron after the nervous impulse happened?

I often see in neuroscience textbooks about how the brain controls everything in the body with different tracts and etc, and it seems that information is always being transmitted, like there's no ...
3
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2answers
57 views

Is there a way to know how many sodium channels are active (conducting) at a given time in the brain?

I was doing some reading about anti-epileptic sodium channel blockers, then wondered how many sodium channels are actually conducting (actively passing ions) at any given time, that is, in an ...
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1answer
102 views

How does the brain manifest and realize the intention to resist sleep?

The question title says it all. What happens in my brain when I resist sleep? I would appreciate explanations on neurotransmitter changes, what areas of the brain activate to resist sleep, what can an ...
4
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1answer
58 views

What determines the shape of the center-surround receptive fields of retinal ganglion cells?

The wikipedia article about receptive fields of visual system tells us the following: The receptive field is often identified as the region of the retina where the action of light alters the ...
4
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1answer
102 views

All-or-nothing-law: law or general principle?

The all-or-nothing principle indicates that a nerve cell fires at maximum potential or not at all, based on a threshold on the stimulus. Is this a statement which is always true, or only ...
8
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1answer
197 views

Are 2 eyes necessary for 3D vision?

To start off: I'm not a biology student, but a computer science major It has always been my understanding that humans have 2 eyes so that we can have 3D vision: the left eye see more of the left side ...
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1answer
56 views

How difficult is it to make a shRNA/miRNA/siRNA to silence/knockdown NaV1.7 voltage gated sodium channels in humans?

There have been various research projects that experimented with shRNA/miRNA/siRNA to specifically silence/knockdown NaV1.7 voltage gated sodium channels in small animals like rats & guinea pigs. ...
0
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1answer
53 views

Nernst equation?

I keep seeing the Nernst equation in two different forms, one using the natural log and the other using log base 10. Could someone explain why there are two different versions, and which should be ...
1
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1answer
43 views

What is 'noise'?

In both my psychology, biology and neuroscience classes, professors are constantly talking about 'noise'. For instance, our perception is limited due to 'sensory noise' in our neurons. I am utterly ...
2
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0answers
36 views

How do Binaural Beats Work?

We have a project on different ways of relaxation. One way I found out was binaural beats. Could anyone please tell me how they work. You guys are masters when it comes to simplifying things! All I ...
4
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1answer
84 views

Relationship between toxicity of drugs and negative effects on brain

Are psychoactive drugs with lower lethal doses more neurotoxic (more damaging to the brain)? For example, tetrahydrocannabinol (one of the active components of cannabis) has a much higher lethal dose ...
4
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1answer
50 views

Is HSV-vector-mediated miRNA expression in dorsal root ganglia stable?

My question is on the following article: "Reduction of voltage gated sodium channel protein in DRG by vector mediated miRNA reduces pain in rats with painful diabetic neuropathy" My question is, do ...
2
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1answer
49 views

Why is stimulation of nerve tissue with a negative pulse called “cathodic” stimulation?

By definition, the cathode is defined as the terminal through which current exits a polarized device. But in the context of neuromodulation, such as spinal cord stimulation, deep brain stimulation, ...
3
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2answers
383 views

Is the Hypothalamus part of the Central Nervous System or Endocrine System

Sorry for a certainly naive question. Some references (for example https://faculty.washington.edu/chudler/nsdivide.html) seem to to indicate that the hypothalamus is part of the Central Nervous ...
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0answers
27 views

Is there any evidence to suggest that exercise reduces the side effects of caffeine?

I heard a friend say: I'm not drinking coffee this week. My body can only process the caffeine if I run at least 15km a week. I found this claim fascinating - that exercise temporarily ...