If a neurotransmitter causes ligand-gated sodium channels to open, what occurs to the membrane?Multiple choice question.HyperpolarizationDepolarization

Analysis of the Question

The question involves understanding the physiological response of a neuron membrane when ligand-gated sodium channels open in response to a neurotransmitter.

Relevant Concepts

1. Ligand-Gated Channels: These are ion channels that open or close in response to binding of a chemical messenger (ligand), such as a neurotransmitter.
2. Sodium Channels: When these channels open, sodium ions (Na⁺) move into the neuron.
3. Membrane Potential:
   • Depolarization: This occurs when the inside of the cell becomes more positive (less negative) compared to the outside, often due to the influx of positively charged ions like Na⁺.
   • Hyperpolarization: This occurs when the inside of the cell becomes more negative compared to the outside, often due to the efflux of positively charged ions or the influx of negatively charged ions (e.g., Cl⁻).

Conclusion

Since opening ligand-gated sodium channels allows Na⁺ ions to flow into the neuron, this influx leads to a more positive membrane potential.

Final Answer

Depolarization occurs when a neurotransmitter causes ligand-gated sodium channels to open.