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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 ...
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7
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How does the synaptic cleft exist?
There are membrane proteins that act as structural components of the gap (i.e. the synapses aren't just floating there, they are anchored to each other via membrane proteins).
https://en.wikipedia....
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7
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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 ...
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6
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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:
...
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5
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Differences between synaptic connections
Neurons are all about specialized structures having specialized roles. You've given a good justification for dendrites---an efficient way to fit lots of connections in a small space. A pyramidal ...
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5
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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 ...
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5
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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 ...
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5
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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?
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 ...
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4
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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 ...
4
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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 ...
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4
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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 ...
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4
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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 ...
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3
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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 ...
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How long does a spiking signal last?
Effective integration time of a typical neuron is in the order of 10-100 ms. You might want to look into this classic paper (read it with a critical mindset):
Shadlen, M. N. and Newsome, W. T. (1994)....
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What is synaptic clearance?
"Synaptic clearance" is referring to the clearing of a neurotransmitter from a synaptic cleft. A synapse is a place where one neuron can stimulate another neuron. The tiny gap between the neurons is ...
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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 ...
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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 ...
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2
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Dendrodendritic synapse through axodendritic synapse at same dendrite?
I'm not sure if you are asking if an axon that sends a signal to a dendrite would then be released from that dendrite to another dendrite?
I don't see how this is possible seeing as the dendrite is ...
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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 ...
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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 ...
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2
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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 ...
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2
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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 ...
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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 ...
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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.
...
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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 ...
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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 ...
2
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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:
...
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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 ...
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Only top scored, non community-wiki answers of a minimum length are eligible