Please help only if you are an expert! I have submitted this question 3 x alread

Question

Please help only if you are an expert! I have submitted this question 3 x already and keep getting only one of the questions answered! these questions all go together. please answer each so I can understand! thank you

2.What is the definition of the time constant? What does the time constant tell you in terms of the electrical signal? Neurons are designed to minimize the time constant – why? What aspect of the neuron’s cable properties are manipulated to minimize the time constant? How are neurons modified (i.e. what is done to the structure of the neuron) to minimize the time constant?

Explanation / Answer

The time constant is the time taken for an EPSP (excitatory postsynaptic potential) to decay by a certain percentage. In other words, when a current or polarization has taken place in a membrane of the neuron, the signal starts to move forward and slowly the signal decays and fades away. The time constant is the measure of this rate of decay how fast or how slow the signal decays during its journey in the membrane. The faster the signal decays the smaller the time constant. Typically time constants of the neuron are around 5 - 20 milliseconds.
The time constant depends on the membrane resistance. Larger the resistance larger will be the time constant.
The time constant describes the rise and fall of the membrane voltage in terms of electrical signal.
Time constant defines the speed at which signal is transferred across the membranes. The neurons must transfer signals as fast as they can. The increased time constant would lead to temporal summation or algebraic summation of repeated potentials. Hence neurons are designed to have the smaller time constant.
The neurons are myelinated with a protective sheath, which is like an insulator. This does not allow the signal to fade away and thus helps to transfer the signal faster.

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