Fig. 1.
A simple model reproduces the diversity of odorant pulse kinetics. (A) Schematic diagram of an odor delivery system. Air flows in the odor chamber with flow rate Q1 controlled by a solenoid valve (q). The odorous stream enters the main delivery tube where clean air flows with rate Q2. x2 is the normalized concentration of odor in gas phase within the volume V (Eqn 7). A photoionization detector (PID) is used to measure the amount of odor exiting the tube. (B) Normalized photo-ionization detector (PID) recordings (gray) and model predictions (black) for six odors for which surface interactions are negligible. (C,D) Parameters of model fitted to PID measurements of 21 odorants for which surface interaction cannot be neglected. Error bars show standard deviation estimated from 30 fits. Colored traces in C show model predictions. w̃, density of odor binding sites on the inner surface of the tube; τa, time scale of odor to surface binding; K̃d, dissociation constant between the odor and surface.