How does sensory adaptation affect olfactory receptor cells?

Sensory adaptation is a phenomenon where the response of olfactory receptor cells wanes over time, causing a person to stop perceiving a smell even when the odor source remains present.1

This process affects the cells in the following ways:

• Reduced Responsiveness: The receptor cells experience a decline in activity, often adapting completely within a few seconds of continuous exposure to an odorant.1
• Partial Adaptation: While long regarded as occurring solely within the receptor, research suggests that these cells may only adapt partially. Rhythmic discharges have been observed in the olfactory bulb long after the conscious detection of an odor has ceased, indicating that some adaptation also occurs within the brain.2
• Recovery: Despite this waning response, olfactory receptor cells are not permanently altered; they become responsive again following an interval without stimulation.1

This adaptation is particularly pronounced for stronger odors and can involve cross-adaptation, where exposure to one scent makes it more difficult to detect another.2