How do sensory receptors convert stimuli into neural signals?

Sensory receptors convert stimuli into neural signals primarily through the mechanisms of depolarization and neurotransmitter release. When a sensory receptor (like those found in the skin, eyes, ears, etc.) is activated by a specific type of stimulus, such as light, sound, or pressure, it undergoes a change in membrane potential known as depolarization. This depolarization occurs due to the influx of ions, particularly sodium ions, which alters the electrical state of the receptor cell.

As the receptor depolarizes, it reaches a threshold that triggers an action potential, which is an electrical impulse that travels along sensory neurons. This action potential is then transmitted to the central nervous system (CNS). The process often involves the release of neurotransmitters at the synapse between the sensory neuron and the subsequent neuron in the pathway. These neurotransmitters bind to receptors on the next neuron, continuing the transmission of the signal.

This mechanism of signal transduction is critical for how we perceive and react to various stimuli in our environment, making it clear why depolarization and neurotransmitter release accurately describe the process through which sensory receptors operate.