Figure 5.

Schematic diagram of receptor coding for single odorants and an odorant mixture. Each odorant activates different but sometimes overlapping subsets of ORs, which define an identity code for an odorant. When the odorants are mixed, a code for the mixture is expected to be the sum of coding patterns of its components. However, when antagonism between the odorants occurs, a smaller number of receptors are activated than the additive number of activated receptors by single odorants. For example, EG is an agonist for the red, yellow, and blue receptors, but an antagonist for the green receptor. MIEG is an agonist for the blue, green, and pink receptors, but an antagonist for the yellow receptor that corresponds to mOR-EG.