Positive feedback in neurons is defined as

Positive feedback in neurons is defined as

• A. Positive feedback
• B. Negative feedback
• C. Inhibition
• D. Facilitation

Answer: (A)

Positive feedback in neurons means the initial change in activity is amplified by the system itself, creating a self-reinforcing loop. A classic example is the generation of an action potential: a small depolarization opens voltage-gated sodium channels, which lets in more Na+ and causes further depolarization, which opens even more channels, rapidly propagating the signal to a peak. This rapid, self-amplifying rise is the essence of positive feedback. In contrast, negative feedback would activate processes that oppose the change and push the membrane back toward resting potential, while inhibition reduces activity. Facilitation involves increased neurotransmitter release at a synapse with repeated stimulation and is a related concept at the synaptic level, but it isn’t the overarching self-amplifying loop that drives the whole neuron's signal like positive feedback does.

Positive feedback in neurons means the initial change in activity is amplified by the system itself, creating a self-reinforcing loop. A classic example is the generation of an action potential: a small depolarization opens voltage-gated sodium channels, which lets in more Na+ and causes further depolarization, which opens even more channels, rapidly propagating the signal to a peak. This rapid, self-amplifying rise is the essence of positive feedback. In contrast, negative feedback would activate processes that oppose the change and push the membrane back toward resting potential, while inhibition reduces activity. Facilitation involves increased neurotransmitter release at a synapse with repeated stimulation and is a related concept at the synaptic level, but it isn’t the overarching self-amplifying loop that drives the whole neuron's signal like positive feedback does.