Question

In general, how is intensity of a neural signal communicated via a neuron?

a. By varying the amplitude of the depolarization.
b. By varying the frequency of successive action potentials.
c. By keeping voltage gated channels open longer to prolong depolarization.
d. By releasing different types of neurotransmitters at the axon terminal.
e. By recruiting different numbers of ion channels to participate in each action potential.

Answer 1

The intensity of a neural signal is communicated by the frequency of successive action potentials, not by the amplitude of depolarization. Strong stimuli trigger action potentials more frequently, which are then transmitted down the axon.

Step-by-step explanation:

The intensity of a neural signal is communicated via a neuron primarily by varying the frequency of successive action potentials. This method is chosen because the amplitude of action potentials is generally consistent; instead, information about the strength of a stimulus is conveyed by the rate at which these action potentials are fired. When the neuron receives a strong enough stimulus, voltage-gated ion channels open, resulting in a depolarizing graded potential.

If this depolarization reaches a specific threshold, an action potential is triggered, which then propagates down the axon. The stronger the stimulus, the more frequently action potentials are generated. This phenomenon can also be facilitated by the axon's diameter, as ions diffusing in a wider axon encounter less resistance, potentially leading to a faster signal transmission.