Figure 1.

Hypothetical scheme of the selection of new olfactory bulb (OB) neurons by odor value-related centrifugal inputs from the olfactory cortex (OC). New OB neurons (green) receive peripheral inputs (red arrow) which convey information of odor identity. New neurons also receive centrifugal inputs from the OC (blue arrow) which promote selection of new OB neurons for survival or death. The central inputs presumably convey information of odor value, while inputs during post-meal sleep period and during startle and fear responses may convey distinct odor value information.