# Questions regarding neurons, axions dendrites and synapse

I am computer science undergraduate student.

I have some questions regarding the neurons and synapse but I can't find them in the internet so easily.

So, to me, I see dendrites as the input, cell body as the processor, and the axons as the output.

1. Is the neuron's activation threshold variable or constant?


What I am interested to know here is, for example, sometimes the neuron fires with 5v other times with 6v, etc... the threshold varies.

2. Are all axons activated at once? or some may be not?


Imagine a neuron has 5 axons. are all the 5 axons sending signal at the same time? Or maybe just 2 of them are sending the signal...Not all of them are transmiting the information at once.

3. Do all axons send the same charge? or is it variable?


Again, a neuron with 5 axons, are they all sending the same signal? or like one of them is sending (5v), another one is sending (3v), another one is sending (2v) and so on... it's not a fixed value.

4. Do all dendrites have the same eletrical charge?


Imagine a neuron with 5 dendrites. Do they all have the same charge like 5v? or one has 2v, another one has 4v, etc... the eletrical charge is variable.

5. Do all dendrites have to be activated so a neuron has a synapse? or it only has to reach the threshold?


Imagine a neuron with 5 dendrites and its threshold is 5v. If the dendrites have different eletrical charge like this: 1st one has 5v, 2nd one has 3v, 3rd one has 2v, 4th has 1v and 5th has 1v.

do you only need to sum the charge of all dendrites until it reaches 5v to have a synapse or you need a certain number of dendrites to be activated first? maybe a mix of both: a certain charge + number of actiavated dendrites

New contributor
Bruno Lebtag is a new contributor to this site. Take care in asking for clarification, commenting, and answering. Check out our Code of Conduct.
• Welcome. Do you mean axons? Do all dentrites have to be activated so a neuron has a synapse? or it only has to reach the threshold? make no sense. – AliceD May 15 at 8:55
• Sorry. I tried to improve my question now. I also fixed some typos. – Bruno Lebtag May 16 at 0:34
• You din;taddress my second comment. Further, have you done any research yourself? It would be nice to know what you've found so far. – AliceD 2 days ago
• I did find today number 1 and 5. 1- the neuron threshold is variable. 5 - if the sum of the excitation minus the inhibition reaches the threshold, that will cause an action potential. but I'm not finding 2, 3 and 4. I think the biggest question is: does the eletrical current value matter or it could be only be seen as 1 (active) or 0 (inactive)? – Bruno Lebtag 2 days ago