Question

What ion contributes most to the resting membrane potential and why?

What is meant by analog and digital modes of neuronal activity?

Is an action potential necessary for release of neurotransmitter? Why or why not?

Answer 1

SOLUTION

PART (A) Sodium and Potassium ions contribute most to the resting membrane potential because the sodium and potassium electrogenic, that is, they produce charge imbalance across the cell membrane (Electric potential is generated due to charge difference).

PART (B) Analog means a continuously variable voltage as sinusoidal.
Digital, on the other hand, means "represented by digits." They may be binary digits as used in computer.

The brain is neither analog nor digital, but works using a signal processing paradigm that has some properties in common with both.
Unlike a digital computer, the brain does not use binary logic or binary addressable memory, and it does not perform binary arithmetic. Information in the brain is represented in terms of statistical approximations and estimations rather than exact values. The brain is also non-deterministic and cannot replay instruction sequences with error-free precision. So in all these ways, the brain is definitely not "digital".
At the same time, the signals sent around the brain are "either-or" states that are similar to binary. A neuron fires or it does not. These all-or-nothing pulses are the basic language of the brain. So in this sense, the brain is computing using something like binary signals. Instead of 1s and 0s, or "on" and "off", the brain uses "spike" or "no spike" (referring to the firing of a neuron).

PART (C) Yes, an action potential necessary for release of neurotransmitter since neurons communicate with each other via electrical events called ‘action potentials’ and chemical neurotransmitters.

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