Question

Discuss two possible molecular mechanisms that may explain how olfactory fatigue occurs

Answer 1

OIfactory fatigue also known as odor fatigue is a name for the common experience of losing sensitivity to odors afler continued smelling,If we smell a substance, and shortly thereafter smell the same substance at a lower concentr­ation, the odor sensation may either be absent or considerably weakened, this is known as self adaptation, for e.g, in case of a person who smokes he will be un able to smell the smoking odor, but the moment he reaches his home it is easily detected by the members at home.

When a series of stimuli of similar strength constantly bombard nerve receptors, (olfactory receptors) the nerves become accustomed to the stimulus. This phenomenon appears to happen because the rate of change within the nerve’s membrane is inadequate to keep up with continuous stimulation, so there is gradual decrease in the responsivness of sensory system, leading to olfactory fatigue.

Olfactory fatigus could occur due to the inactivation of ion channels like calcium channels, in the membrane that generate the electrical signal, so after a stimulus causes a receptor cell to produce an electrical signal, the cell membrane soon stops allowing ions to flow, thus preventing further signals resulting in olfactory signal.  Removal of the stimulus followed by restimulation activates the process all over again