Questions tagged [neuroscience]
The study of the structure and function of the nervous system and its components.
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Is there such a thing as transcranial magnetic inhibition? inhibit regions of the brain?
is there such a thing as transcranial magnetic inhibition?
There is an instrument capable of inhibiting regions of the brain as does transcranial magnetic stimulation, but in reverse.
By inhibiting, I ...
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Term for context based behavior?
Is there term in neuroscience that describes change in neuronal circuits depending on context: low sugar/fear/... => hormones => different pathways of behavior ...?
I know that is something from ...
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Does electrotonic spread/conduction occur in saltatory conduction?
Even as textbooks, and almost all web pages I've seen so far, explain electrotonic spread/conduction as the passive current flow along an axon, they do so with continuous conduction only. Apart from ...
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Is a “Nerve” a cell or a tissue? [closed]
Nervous tissue includes Neurons and Glial cells. Neurons have soma and other projections (neurites) namely Axon and Dendrites. Axon or dendrites of a nerve cell covered with endoneurium
is called ...
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What percentage of the brain is memory | Storage of thoughts, episodes
I was reading the article, in which it is mentioned that human brain constitutes 2.5 petabytes of memory. This made me wonder how much of the brain is associated with memory itself. If we categorize ...
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What is the most specific behavior we're able to control or induce with optogenetics?
Optogenetics is very widely used in neuroscience to study how behavior is controlled by populations of neurons. For example, in a highly cited 2011 Nature paper, Lin et al. show that they can induce ...
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Is practice of motor skills an environmental factor or a physical factor? [duplicate]
Apologies for asking the same question twice. I'm leaning on physical factors, just would like someone's confirmation. Thank you; much obliged.
What type of factor is practice of motor skills?
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Why does increasing the space constant increase conduction velocity in myelinated neurons if nodes of Ranvier are constantly spaced?
If depolarisation at one node of Ranvier triggers, by passive conduction, an action potential at the next node of Ranvier, why does increasing the space constant increase conduction velocity? Surely ...
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How can tooth enamel feel pain when drilled by a dentist?
Enamel has no nerves, so theoretically a tooth should not feel any pain when a dentist bores into it. Yet still we use anesthetics...
Maybe itās dentin's fault? It apparently has some tubes filled ...
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2answers
42 views
Has anyone yet figured out how sensory signals for eyes and ears are encoded by our organ into electrical signals? [closed]
The most obvious way to give sight to blind and hearing to deaf is to give them a replacement organ for these. In order to do that we would need to understand how our eyes and ears encode sensory ...
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What type of factor is practice of motor skills?
I recently asked a question about the cause of motor laterality: What causes motor laterality/ side dominance?
I understand that there can be genetic factors, epigenetic factors, or environmental ...
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1answer
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Term for a prey animal's recognition that something potentially threatening is looking at it?
On my daily walks I frequently see individual or small groups of cattle egrets. At first I would try to photograph them but they would fly away. This vexed me because they ignored everyone else ...
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1answer
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Does the corpus callosum have a significant relationship with motor memories/ muscle memories?
With the corpus callosum located in the cerebrum, and motor memories having a closer relationship to the cerebellum (which I'm not quite sure about), is there a significant relationship between the ...
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What causes motor laterality/ side dominance?
I would like to understand what leads up to motor laterality, or side dominance of motor skills.
I made this assumption that it depends on neuroplasticity and the side in which one first learns the ...
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2answers
56 views
Can below-threshold potential changes of neurons convey information?
In neuroscience we learn that when the membrane potential of a neuron reaches a threshold (typically around ) it "spikes": That is, it actively propagates a signal. I have two related ...
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What are “intrinsic hypothalamic fibers”? (From an article on neuronal mechanisms of sexual desire)
I came across the phrase intrinsic hypothalamic fibers which I cannot understand. What is meant by intrinsic - that these fibers (long myelinated axons?) start in the hypothalamus? Or that they start ...
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Phantom Limb | Is that even possible?
I am fascinated by the fact that an amputee can control their robotic arm by thinking of the actions they would normally execute when the limb was present.
The mind sends signals to the nerve endings ...
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Why do we have both on and off bipolar cells?
I have a question regarding the reason behind the 2 bipolar cells.
So, from my understanding we have both on and off bipolar cells and from the numerous diagrams I have seen, I find that most show a ...
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2answers
23 views
Action potential attenuation in unmyelinated axons vs demyelinated axons
I learnt that action potentials travel much faster along myelinated axons, and when these axons are demyelinated the action potentials travel much slower and sometimes die out. Why do action ...
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When assessing a threat, does the amygdala compare the stimulus to memories of the amygdala or the hippocampus?
Two excerpts from the one article.
My understanding of this excerpt is that the amygdala is using its own memories:
The amygdala learns how to respond to various stimuli based on itās reference to ...
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Myelinated vs Un-myelinated
If an axon is completely myelinated (doesn't even have Nodes of Ranvier), is it faster than an un-myelinated axon when conducting action potentials?
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At small axon diameters (<1 µm), why does myelination not increase neuronal conduction velocity?
As per the diagram below (and other graphs available online), why do unmyelinated fibres have a higher conduction velocity than myelinated fibres when the axon diameter is less than around 1 Āµm?
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1answer
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How do we know that selective agonists are indeed selective?
Suppose we know that compound X is a selective agonist of receptor Y, meaning that it binds only this receptor Y and no other. But how do we know this that it doesn't bind some another receptor? I ...
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Myelination of 1st Order Neurons in Spinal Cord Ascending Tracts
When a 1st order sensory neuron enters the Dorsal Column Ascending Pathway (i.e. Spinal Cord), does it get its myelination from Oligodendrocytes (as inside CNS) or it retains Schwann Cell myelination?
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Alternative hypothesis for learning in brain beyond the hebbian rule
I was reading on wikipedia that there are exceptions to the hebbian rule, and I was curious about the possibilities of other hypotheses of how learning occur in the brain. So I would like to know:
...
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Can we say that the source of the most circulatory regulation in the human is the nervous system?
local regulation of blood flow and Baroreceptors, both stimulate the neurons and send messages to the brain. so can we say that the source of the most circulatory regulation in the human is the ...
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3answers
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If the Brain can store as much information as a billion hard disks why cant i memorize a single word document of random letters?
I read a lot of articles on this and all seem to agree that the brain storage in neural connections is tremendous but that doesnt explain why we forget things so easily and have such a modest memory ...
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Why are the sympathetic and parasympathetic axons different, in terms of presynaptic and postsynaptic length?
Does the parasympathetic system have a long presynaptic efferent axon because it takes a great distance to reach target organs from the brain stem or sacral region of the spine? Does the sympathetic ...
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Alzheimer's datasets highlighting role of individual genes
A question to the folks who studies Alzheimer's disease here.
My colleagues and I have developed a new program that predicts the master regulators based on transcriptomic changes (yes, another one). ...
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1answer
101 views
Vitamin A Deficiency
I have a quick question regarding Vitamin A deficiency.
The photoreceptor molecules in both rods and cones have the same general structure which is retinal which is bound to a protein called opsin ...
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1answer
61 views
First neurotransmitter?
Cnidaria are considered to be the first phyla to develop a nervous system. Nervous systems having 1, 2 and three neurons are considered to have appeared first in Cnidaria, with 2-neuron nervous ...
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Adding potassium outside of neuron: Hyper- or De- polarization?
At rest, the equilibrium potential for potassium given by the Nernst equation is ~ -80mV. Since the cell is mainly permeable to potassium, this is the reason for the cell membrane's rest potential to ...
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Doubt related to nerve impulse transmission
Naturally, the extracellular fluid has more sodium ions and the axoplasm has more potassium ions. Since there are more potassium leakage channels than sodium leakage channels on axoplasm, it is more ...
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1answer
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Visual receptive fields
What I know about centre-surround type receptive fields is that depending on whether the region is on or off, the response to being stimulated is either excitatory or inhibitory respectively. So if a ...
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1answer
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Synapses of inhibitory neurons
I sometimes read of "inhibitory synapses". But I understand that when the neuron is inhibitory, all of its synapses will be inhibitory (so it is a property of the neuron, not only the synapse) - is ...
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1answer
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What is the significance of the amplitude of brain waves?
What does the amplitude of brain waves represent and to what neuronal activities is this amplitude related to?
For example, in a hypothetical situation, the frequency of brain waves is kept the same, ...
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120 views
What brain regions consume the most energy?
It's well known that the human brain consumes roughly 20% of the body's energy, and that grey matter is much more energy-intensive than white matter.
Beyond this basic information, it seems difficult ...
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1answer
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Meaning of “external demands” in a paper describing the gut-brain axis
From "Brain Gut Microbiome Interactions and Functional Bowel Disorders":
In response to external and bodily demands, the brain modulates individual cells (ECC ā enterochromaffin cells; SMC ā ...
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Does the brain absorb heme and non-heme iron differently?
I know that for the brain to absorb iron, the iron must first pass through the blood brain barrier. Is this absorption different for heme and nonheme iron?
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How does lactic acid cause muscle twitching?
It is well-known that lactic acid buildup (often caused by workouts) causes muscle twitching.
Does anyone know HOW lactic acid achieves that effect?
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Which hormones, metabolites, or other molecules build up as the day progresses, other than melatonin and adenosine?
Melatonin and adenosine reach peak levels around midnight/bedtime. I was wondering what other molecules also buildup as the day progresses. Particularly molecules that affect the CNS and/or immune ...
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Biophysically, how to change from a tonically firing neuron to an occasionally firing one?
In terms of membrane properties, size and neuronal biophysics (assuming no change in incoming excitation), how can a tonically firing neuron become (say during development) an occasionally bursting ...
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2answers
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Are “sympathetic nerves” the same as “cardiopulmonary splanchnic” nerves?
I've gathered from a number of sources (e.g., Patel (2015), Wikipedia, and here) that the sympathetic nerves leaving the sympathetic trunk to innervate the heart and lungs are called "cardiopulmonary ...
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Would it be possible to determine the strength of each neural connection in a connectome data set?
I understand that a connectome is a map of connections between neurons.
Would it be possible with current day technology to create a more detailed map that gives not only the connections themselves ...
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1answer
134 views
Are there people blind to touch?
There are people who completely blind or deaf. Are there people who are completely blind to touch in a particular area or in the entirety of their body? If not, are there people in whom the ...
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1answer
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What does it mean to say that the sympathetic nervous system is organized for diffuse activity?
"Sympathetic activities generally serve to mobilize the energy stores of the body, to increase the blood flow through certain regions (e.g., the heart) at the expense of other areas (e.g., the ...
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1answer
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Why isn't hearing the same as tasting? How do we feel and differentiate external stimuli?
When I was at school, I learned that:
Skin, tongue, ears, and other sensory organs have sensors/convertors that turn external environment stimuli into "electric" signals.
Neurons send information as ...
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1answer
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What does sympathetic and parasympathetic 'tone' mean?
My professor's lecture notes say that " The basal rate of firing is called āsympathetic toneā and 'parasympathetic tone" , but a table I found on the internet says that the parasympthetic system has ...
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1answer
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Question about the Derivation of the cable equation for neurites
I read in Wikipedia how the cable equation was derived (here) and had a specific problem regarding one of its equation:
At the start of the derivation it states that we first need to pretend that the ...
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Why doesn't the spinal cord get thicker the further up we go?
The cervical and lumbar enlargements exist on the spinal cord as a result of the increased nerve input/output required for the arms and legs respectively.
However, I don't understand how the ...
