What is the threshold of the action potential of a neuron?

What is the threshold of the action potential of a neuron?

• A. -70 mV
• B. -55 mV
• C. -40 mV
• D. 0 mV

Answer: (B)

The threshold for an action potential in a neuron is typically around -55 mV. This is the key membrane potential that must be reached for an action potential to be initiated. At rest, a neuron has a membrane potential of approximately -70 mV, which is considered the resting potential. When the neuron is stimulated, depolarization occurs, leading the membrane potential to become less negative. The threshold of -55 mV signifies that sufficient depolarization has occurred to open voltage-gated sodium channels, allowing sodium ions to rush into the neuron, thus generating the rapid depolarization phase of the action potential. If the membrane potential does not reach this critical threshold, the neuron will not fire an action potential, and normal signaling will not occur. In summary, -55 mV is crucial as it marks the point at which the action potential process begins, contributing to the rapid communication of signals within the nervous system.

The threshold for an action potential in a neuron is typically around -55 mV. This is the key membrane potential that must be reached for an action potential to be initiated. At rest, a neuron has a membrane potential of approximately -70 mV, which is considered the resting potential. When the neuron is stimulated, depolarization occurs, leading the membrane potential to become less negative.

The threshold of -55 mV signifies that sufficient depolarization has occurred to open voltage-gated sodium channels, allowing sodium ions to rush into the neuron, thus generating the rapid depolarization phase of the action potential. If the membrane potential does not reach this critical threshold, the neuron will not fire an action potential, and normal signaling will not occur.

In summary, -55 mV is crucial as it marks the point at which the action potential process begins, contributing to the rapid communication of signals within the nervous system.