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How do neurons find each other?

Q: We know neurons can organize into very complex networks, but how? The answer is your first guess: Neurons find other target neurons with specific chemical signals. Q: What are the names of said ...
leekaiinthesky's user avatar
7 votes
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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?

Colocalization of a protein with another structure is necessary but not sufficient to say that the protein is a component of that structure. Mixed into the concept of a structure's existence is the ...
Ryan's user avatar
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6 votes
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Understanding the picture of a synapse

You can tell that the structures labelled At are axons, or rather axon terminals, due to the presence of the synaptic vesicles. I think this is a fine photo that's a bit more a clear representation: ...
CKM's user avatar
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6 votes
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Enigmatic picture of an axon

Your belief is wrong; axons form synapses along their lengths. I'm most familiar with these being referred to as en passant boutons. See for example this image and description from: https://synapseweb....
Bryan Krause's user avatar
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5 votes

Under what conditions do dendritic spines form?

Two classes of factors contributing to spinogenesis have been described in the literature, based on whether they can be considered extrinsic or intrinsic to the dendrite (my classification). Here is a ...
vkehayas's user avatar
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5 votes
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What makes synapses stay "fixed"?

Synapses are held together by adhesion molecules, like cadherins and neuroligins/neurexins, so they aren't just loose adjacent membrane, they are securely anchored in place. The adhesion molecules ...
Bryan Krause's user avatar
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5 votes

Is colocalisation of a protein with a presynaptic marker sufficient evidence to say that the protein is a component of axon terminals?

Empirical science is not based on proof, but on evidence. No one study is the final word on anything. "Sufficient evidence" is entirely up to the person operating on the evidence and what ...
Bryan Krause's user avatar
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4 votes
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Why do SRIs help in serotonergic neurotransmission?

Excellent question. Different neurotransmitters operate at different temporal scales (and even the same transmitter can operate at different temporal scales). Examples of the fastest-acting ...
Bryan Krause's user avatar
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4 votes
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Can neurotransmitter concentrations in the synaptic cleft add up if there are several impulses in quick succession?

The answer by bpedit is a good explanation of temporal/spatial summation, which can be partly a postsynaptic phenomenon (due to membrane time constants or second messenger sytems, for example). Your ...
Bryan Krause's user avatar
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4 votes

Human brain is superior than till-date computers, yet why we perform poor than computer?

Three reasons: Most of the storage capacity of the brain is used to store implicit knowledge. For example how to move your body, how to automatically recognise objects or how to hear and parse your ...
BlindKungFuMaster's user avatar
4 votes
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Why chemical synapses are more common?

Electrical synapses are hardly synapses at all, they allow the connected cells to share some components of their cytoplasm. This really makes them more like one "super cell" rather than ...
Bryan Krause's user avatar
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4 votes
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How could memory work without long-term potentiation?

I will not comment on the particular author's views and answer the question in the title. There are five conceivable theories for neural memory (following Hebb (1)): Memory is sustained by ...
vkehayas's user avatar
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3 votes

What determines the influx of calcium ions in the voltage-gated ion channels?

Short Answer Extracellular calcium ions’ “source” are probably cells called astrocytes that connect to both neurons and blood vessels. Calcium ions outside the pre-synaptic neuron are high in ...
Fuzzy Bee's user avatar
  • 124
3 votes

What material fills the synaptic cleft? Is it water?

There are two types of synapses namely Electrical synapse and Chemical synapse. In electrical synapse there is physical contact between two cells through gap junctions. In chemical synapse there is a ...
Science123's user avatar
3 votes

How do neurons find each other?

This is a very good question. There are specific chemical signals, for instance: 1.) LRR proteins, which help signal neurons to each other. These are transmembrane proteins which are characterised ...
Jay's user avatar
  • 77
2 votes

Can neurotransmitter concentrations in the synaptic cleft add up if there are several impulses in quick succession?

The addition of multiple impulses is termed summation and is instrumental in whether an action potential will be induced in the post-synaptic neuron. If the neurotranstitter released by one action ...
bpedit's user avatar
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2 votes
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Do presynaptic neurons and postsynaptic neurons have different compositions of neurotransmitter receptors and transporters?

Typical bouton-spine synapses are formed as an interactive process between the pre- and post-synaptic cells (Scheiffele, 2003). There is communication between pre- and post-synaptic cell through ...
Bryan Krause's user avatar
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2 votes
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Why use embryonic neurons to study protein knockouts/mutants in long term potentiation?

Some suggestions, there may be more: 1) The knockout may not be viable to adulthood (the animals die). Perhaps heterozygotes are viable, but to test the full knockout you need a homozygote. 2) Even ...
Bryan Krause's user avatar
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2 votes

What does fail-safe mean in transmission at electrical synapses?

To understand what failure means in this context, we need to know a bit about how signals are communicated from one neuron to another. Types of signals First of all, it's important to know that ...
khonegger's user avatar
2 votes

What material fills the synaptic cleft? Is it water?

The components of the inter-stitial fluid will be dependent on where the synapse is though yes it will be aqueous. Good old fashioned diffusion over a concentration gradient will be responsible for ...
Sarra's user avatar
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2 votes
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Exocytosis of synaptic vesicles

That sentence is located in a paragraph titled "Stages 5-7: Endocytosis and recycling": it's talking about recycling exocytosed membrane which is necessary for making vesicles for further exocytosis. ...
Bryan Krause's user avatar
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2 votes

How fast does activity affect synaptogenesis?

Synaptogenesis at such a fine temporal resolution is currently still best studied in animal models and reduced preparations where the activity levels can be more precisely controlled and advanced ...
vkehayas's user avatar
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2 votes

What makes synaptic vesicle release probabilistic?

From the source you provided, the answers seem to be outlined well from the authors' sentence that states: The Pr [release probability] of SVs [synaptic vesicles] at the AZ [active zone] is set by ...
Science Is Golden's user avatar
2 votes
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Im struggling to see how these are presynaptic terminals/knobs and not post synaptic

The fibers in green are axons and axon terminals from other neurons, not the one colored orange. Yes, there would be post-synaptic structures associated with these but those are not drawn in this ...
Bryan Krause's user avatar
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2 votes
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A question concerning the strength of synapses

What you are describing is exactly how long-term potentiation/LTP (or depression/LTD, for that matter) is measured electrophysiologically. Here's an example from a 1988 review by Nicoll et al: ...
Bryan Krause's user avatar
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2 votes
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Definition of synaptic strength

Synaptic strength is defined as the average amplitude of postsynaptic potential evoked following a presynaptic action potential. This is a correct definition. Synaptic strength is a fairly abstracted ...
Bryan Krause's user avatar
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1 vote

Im struggling to see how these are presynaptic terminals/knobs and not post synaptic

The green ones you see are the synaptic knobs or presynaptic terminals of other neurons of which some lie on the surface of dendrite of the given neuron(Axodendritic) and some on the soma of the ...
Roy's user avatar
  • 11
1 vote

What determines the influx of calcium ions in the voltage-gated ion channels?

So, let's use a neuron to neuron connection as an example. Calcium is released into the neuron when voltage gated ion channels, specific to calcium, open. These channels can only open when there is ...
ennui's user avatar
  • 61

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