Elimination of Adult-Born Neurons in the Olfactory Bulb Is Promoted during the Postprandial Period

Granule cells (GCs) in the mouse olfactory bulb (OB) continue to be generated in adulthood, with nearly half incorporated and the remainder eliminated. Here, we show that elimination of adult-born GCs is promoted during a short time window in the postprandial period. Under restricted feeding, the number of apoptotic GCs specifically increased within a few hours after the start of feeding. This enhanced GC apoptosis occurred in association with postprandial behaviors that included grooming, resting, and sleeping, and was particularly correlated with the length of postprandial sleep. Further, deprivation of olfactory sensory experience in the local OB area potentiated the extent of GC elimination in that area during the postprandial period. Sensory experience-dependent enhancement of GC elimination also occurred during postprandial period under natural feeding condition. These results suggest that extensive structural reorganization of bulbar circuitry occurs during the postprandial period, reflecting sensory experience during preceding waking period.