Final answer:
The concept that neurons communicate the strength of signal by altering the action potential amplitude is false; instead, signal strength is indicated by the frequency of action potentials, operating on an all-or-none principle.
Step-by-step explanation:
The statement that neurons communicate the strength of signal by altering the amplitude of action potential deflection is false. Neurons do not use changes in the amplitude of action potentials to convey the strength of a signal. Instead, all action potentials have the same magnitude, following an all-or-none principle. The strength of a signal is represented by the frequency of action potentials and sometimes by the number of neurons transmitting those signals, not by changes in action potential amplitude.
An action potential is a change in voltage of a cell membrane in response to a stimulus, leading to the transmission of an electrical signal unique to neurons and muscle fibers. When a neuron receives a strong enough stimulus, voltage-gated ion channels open, leading to a rapid influx of Na+ ions, which causes a reversal of the resting membrane potential and generates an action potential. This electrical event travels along the axon and triggers neurotransmitter release at the synaptic terminal.
The idea that action potential amplitude can vary with the strength of a signal is a common misconception. However, the concept of graded potentials is often confused with action potentials. Graded potentials can indeed vary in amplitude and summate to reach the threshold needed to trigger an action potential, but once an action potential is initiated, it always propagates at a fixed amplitude.