A neuron's membrane potential goes from -90 mV to -10 mV. Which of the following terms describes this change?

• A. Hyperpolarization.
• B. Polarization.
• C. Depolarization.
• D. Repolarization.

Answer: (C)

Verified step by step guidance

1. Understand the concept of membrane potential: Neurons have a membrane potential, which is the electrical potential difference across their cell membrane. This potential is typically negative inside the cell compared to the outside.
2. Define depolarization: Depolarization occurs when the membrane potential becomes less negative (moves towards zero) compared to the resting potential. This is often due to the influx of positive ions like Na+ into the neuron.
3. Analyze the given change: The neuron's membrane potential changes from -90 mV to -10 mV. This change indicates that the membrane potential is becoming less negative.
4. Compare with other terms: Hyperpolarization refers to the membrane potential becoming more negative than the resting potential. Repolarization is the process of returning to the resting potential after depolarization. Polarization generally refers to the state of having a membrane potential.
5. Conclude the correct term: Since the membrane potential is becoming less negative, the correct term to describe this change is depolarization.