Which nutrient is directly involved in the generation of action potentials in neurons by contributing to the depolarization phase?

• A. Iron (Fe)
• B. Vitamin C
• C. Sodium (Na\(^+\))
• D. Calcium (Ca\(^{2+}\))

Answer: (C)

Verified step by step guidance

1. Understand the concept of action potentials: Action potentials are rapid electrical signals that travel along neurons. They are initiated by changes in the membrane potential, specifically during the depolarization phase.
2. Learn about the depolarization phase: During depolarization, the inside of the neuron becomes less negative (more positive) compared to the outside. This is caused by the movement of positively charged ions into the neuron.
3. Identify the key ion involved: Sodium ions (Na⁺) play a critical role in depolarization. Voltage-gated sodium channels open, allowing Na⁺ to flow into the neuron, which increases the positive charge inside the cell.
4. Differentiate sodium from other nutrients: While other ions like calcium (Ca²⁺) and iron (Fe) have important biological roles, they are not directly involved in the depolarization phase of action potentials. Vitamin C is not an ion and does not contribute to this process.
5. Conclude the role of sodium: Sodium (Na⁺) is the nutrient directly involved in generating action potentials by contributing to the depolarization phase through its influx into the neuron.