Questions tagged [neuroscience]
The study of the structure and function of the nervous system and its components.
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how many bipolar cells connected to a ganglion cell?
Is it that only one bipolar cell is connected to one ganglion cell (which (ganglion cell) is connected to only one LGN neuron cell)?
I mean if more than one bipolar cell is connected to a ganglion ...
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what does concentric antagonistic areas in the retina mean?
"concentric antagonistic areas seen in retinal and LGN receptive fields." (Source: Neuroscience: Exploring the brain)
So the receptive field of a ganglion cell is either ON or OFF center. ...
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Would asymmetrically positioned eyes impair vision?
Assuming one eye is 5 cm further down compared to the other, would that somehow change perception if the brain has long enough to deal with that incoming information? For example, if you were born ...
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Are parasympathetic nerves different from motor and sensory nerves?
So the nerves leaving the spinal cord are either motor or sensory (only?). But what about the cranial nerves? For example, the cranial nerve vagus is a parasympathetic nerve. Are parasympathetic ...
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How are on and off bipolar cells of the retina arranged?
In the retina, there are both on and off bipolar cells. But how are they spread out in the retina? Are they so, that there is one of each after one another? Or are there areas where there are clusters ...
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Do hair cells in the ear also vibrate at frequencies outside our hearing spectrum?
(The question has its origin because I asked myself in how far frequencies outside our perception can harm our hearing.)
First of all, the energy of a mechanical wave (in this case, the sound wave, ...
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Does the molecules in nerve cell membrane change 100% during the life of the nerve cell?
In their lifespan nerve cells do not divide and so they stay the same. They do get damaged sometimes and require some maintenance and change their axons a bit. They also require a lot of energy so ...
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Inheritance of child behavior based on daily life experiences of the parent
Our brain is a large network of neurons connected with each other.Our daily experiences change how our neurons are connected.Some experiences create better connections between two neurons A and B and ...
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What does motor writing mean in neurology?
In Zoltan Torey's The Conscious Mind, the author discusses the emerge of language:
Adding weight to the thesis of the stage-wise evolution of language, Bickerton (1995) noted that
the linguistic ...
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Why do V_Na and V_K stay unchanged in Hodgkin-Huxley model?
In the Hodgkin-Huxley model, ionic current $i_\mathrm{Na}$ and $i_\mathrm{K}$ are given by
$$
i_\mathrm{Na}=g_\mathrm{Na}(V_\mathrm{m}-V_\mathrm{Na})\\
i_\mathrm{K}=g_\mathrm{K}(V_\mathrm{m}-V_\mathrm{...
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How to convert Kilo Units (KU) to mg? [duplicate]
Im searching for AChE (Acetylcholinesterase) and on sigma-aldrich it is showing 2 KU or 2000U/mg of protein and on MedChemExpress it is showing 50mg then how can we calcute how much will be the drug ...
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Proportion of cell layers in the different areas of human cortex
I am looking for any scientific paper or book which could help me find the different proportion of layers across the different areas of the human cortex. I am working on a research project which ...
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Relation between image on retina and the real one: looking at the two objects that are 45 degrees apart, what's the distance in the actual image?
These are what I understand about the vision.
lights come through the pupil.
an inverted image of the real objects is formed on the retina. which is determined by the angles.
(so (a, d) and (b, c) ...
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Why is there a negative sign before voltage in the gate variable functions of the Hodgkin-Huxley model?
In Hodgkin and Huxley's articles (1952, J. Physiol.; 1990, Bulletin of Mathematical Biology), the gate variables are formulated as
In particular, as $V$ increases, $\alpha_n$ decreases and $\beta_n$ ...
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What does bregma -4.36mm mean?
I am reading a journal paper. In this paper, they inject adeno-associated viruses into the brains of rats. In the below figure, there is something that I want to clarify:
In Figure A, I am not sure ...
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Why is the anterior pituitary not considered part of the diencephalon?
According to the wikipedia page on the diencephalon, the posterior pituitary gland is considered part of the diencephalon, but the anterior is not. Is there a reason that these two lobes of the same ...
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What are all the possible abnormalities in our body that will result in ataxia?
So I know that ataxia is caused by loss of proprioception.I only know that dorsal column medial leminiscal pathway carries proprioceptive fibre to the cerebellum.So in theory damage to either this ...
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What are the factors affecting reaction time and/or reflex velocity?
So there was this video of a cat killing a snake: Cat reaction time
and another of a bobcat killing a rattlesnake Bobcat kills rattlesnake
And then this from wikipedia on sand cats:
In the Ténéré, a ...
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How can animals defecate or urinate in fear if the nervous system seems to opposes it?
How do animals defecate and/or urinate in fear even though their 'flight or fight' response seems to oppose it? I have seen many cats and dogs urinate and defecate when they experience extreme fear. ...
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Why does Sanjay Gupta's brain look so unusual? (brain model shown on CNN) The subdivisions don't look like the lobes I learned in school
above: Screenshot from CNN's May 18, 2023 Feinstein’s office confirms broader health complications, contradicting senator’s denial below: from anatomyinfo.com's Parts of the Brain
Neurosurgeon Dr. ...
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Stroke research question - has there been research in mirroring muscle electrical signals from a good limb to the bad one?
Transcutaneous electrical neural stimulation is an established tool to help stroke victims recover use of a paralyzed limb by engaging neuroplasticity. Has anyone here heard of research where you wear ...
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How does brain activity change when focusing on something within peripheral vision, as opposed to the fovea?
Normally when looking around, we mentally focus on what we see within our fovea, as that is where we have the greatest visual acuity. However, it is still possible to focus (both physically with the ...
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What are the key mechanisms of control and transport of ATP from mitochondria to synapse in active firing neurons?
I am working with a group in the field of neuronal activity (in computational neuroscience), in specific the firing rates at different ensemble/population hierarchies.
It is well established that ...
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Have elephants (or any species other than humans) been known to cover their dead?
I was just reading this blog on HarperCollins website about 5 animals that grieve. Of elephants, the following claim is made:
They bury their dead and pay tribute to the bodies and to the bones. [my ...
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Is colocalisation of a protein with a presynaptic marker sufficient evidence to say that the protein is a component of axon terminals?
I am reading journal papers about the subcellular localisation of the insulin receptor (IR) in neurons.
I have read a paper stating that IR is highly enriched at synapses, localising to both the ...
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Action Potential and Impulse Direction
My textbook describes generation of action potential due to an "induced increased membrane permeability to $Na$+ ions" and presents the ad hoc fact that electric current would flow from the ...
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Is there a quantitative report for cortical homunculus?
Almost all websites that I see for cortical homunculus only show the final picture with some qualitative descriptions such as "hands have more dexterity and occupy more motor cortex."
But is ...
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Which co-transmitters are released first?
I understand that a single neuron can release different neurotransmitters depending on the frequency of its stimulation (see https://www.ncbi.nlm.nih.gov/books/NBK10818/). As the frequency of ...
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Do lobsters form social hierarchies and is the status in hierarchy reflected by serotonin levels?
In his book 12 rules for life Jordan Peterson claims that:
Consider serotonin, the chemical that governs posture and escape in the lobster. Low-
ranking lobsters produce comparatively low levels of ...
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What is the evidence for cognition being mainly confined to the brain?
We believe that the processes of cognition are mainly confined to the brain.
What is the evidence for that?
I understand that the brain shows increased oxygen saturation in fMRI scans while thinking ...
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Why chemical synapses are more common?
Reading into the types of synapses I found out that there are two types of them; electrical and chemical.
chemical synapses use neurotransmitters to transmit impulses, are slower than electrical ...
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Are afterimages centrally regulated?
As I understand, negative afterimages might be induced by retinal cone bleaching or neuronal adaptation. I have heard that some experiments have suggested that afterimages can be centrally regulated. ...
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Emotions in Animals Based on Neuroscience
I know very little about the subject, so please forgive any misunderstandings in the question. First of all, by emotion, I mean feelings of pleasure and suffering and not merely just sensory ...
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What happens if we lose voluntary control of our breathing?
Breathing can be controlled voluntarily, even though it is automatic. What happens if a person loses voluntary control of their breathing? How much would it effect day-to-day life? What are its ...
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electrotonic spread and screening
(In physics.stack I have been suggested to post my question also here.)
In the classical theory of passive neurons (where the action potential is not yet excited), the voltage is successfully ...
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NMDA receptor depolarization
I learnt that two factors for NMDA receptor channels opening are:
1)Binding of glutamate
2)Depolarization of postsynaptic cell (to remove the Mg+2 block)
Given that depolarization starts in axon ...
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Do secretomotor neurons activate for secretory cells due to the absence or presence of water and electrolytes? Why?
I read this passage in a book called Integrative Action of the Autonomic Nervous System by Wilfrid Jänig. In this book, he states
Reflex pathways involved in the regulation of secretory cells and/or ...
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Where in the cochlea are frequencies below 200 Hz detected?
I understand that different frequencies are detected in different positions along the cochlea.
I'm also aware that the range of human hearing is roughly between 20 Hz and 20 kHz.
However, looking at ...
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Would muscles still twitch if the applied potential is reversed?
In Galvani's experiment with frog legs, he applies an electric potential across the muscles of a frog which causes the leg muscles to contract. What would happen if the polarity was reversed (I do not ...
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what is the major mechanism of habituation?
I am learning the habituation and sensitization in Aplysia I understand the habituation occurs at the pre-synaptic side, but I see two different explanations, both of which sound reasonable to me and ...
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Are there internal systems of organisms which acquired the functions which they were not evolved to perform?
In his research on the issue of belief formation Daniel Gilbert (1991. How Mental Systems Believe) claimed that cognition "is an evolutionary outgrowth of [perception]." What he meant is ...
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Will lidocaine stimulate photoreceptors?
Lidocaine apparently blocks voltage-gated sodium channels in sensory neurons and thus prevents action potentials, but photoreceptors like rod cells require hyperpolarization (through blockage of its ...
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Unbounded synaptic weight in Hebb’s rule
I am new to neuroscience and apologies in advance if this is a very trivial question. I want to model the synaptic weights of neurons and using the discrete Hebb’s update rule
$$w_{n+1}=w_n(1+c)$$
...
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Molecular Signaling: Why is it more difficult to study membrane-bound signaling molecules compared to soluble ones?
I am reading the textbook Neuroscience (6th ed.) by Dale Purves and colleagues. In one of the chapters (Chapter 7, Molecular Signaling within Neurons), I am reading about the different types of ...
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If tinnitus is, in many cases, caused by damaged ear hair cells, couldn't it be solved by a mini cochlear implant that sends a constant signal?
If my understanding is correct, tinnitus is in most cases caused by damage to the inner ear hair cells, especially on the basal parts of the cochlea, which correspond to high frequencies. So, for ...
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Is there a good protocol for bilateral decortication in rodents?
I was thinking about using bilateral decortication in rodents (preferentially mice) to study the roles of certain brainstem areas in cognitive tasks in the absence of cortex. However almost all ...
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What are layers in the Blue Brain Project?
I was watching Bedlewo: Topology meets neuroscience when the lecturer mentions that data is available here. I might find it an interesting challenge to do some exploratory data analysis, but I want to ...
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How does the central nervous system create the feeling of physical sensation in our consciousness? [closed]
I know sensory neurons that respond to light and physical sensations (pressure, temperature) exist throughout our body, giving us information about our surroundings.
For instance, when I push the tip ...
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Why does the concentration gradient of one ion represent the entire cell in the equilibrium potential of an ion? [closed]
The Nernst equation for the equilibrium potential of an ion(in this case potassium),
$$E_{eq,K^+} = \frac{RT}{zF} \ln \frac{[K^+]_{o}}{[K^+]_{i}}$$
includes the ratio of the concentration of that ...
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Need help identifying vascular structures in brain matter
I am working on PET images of the brain. The neuro-oncologist I'm working with identified 2 large high-intensity regions as vascular structures. I've been meaning to ask what structures these are ...
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