Continuous postnatal neurogenesis contributes to formation of the olfactory bulb neural circuits and flexible olfactory associative learning.

The olfactory bulb (OB) is one of the two major loci in the mammalian brain where newborn neurons are constantly integrated into the neural circuit during postnatal life. Newborn neurons are generated from neural stem cells in the subventricular zone (SVZ) of the lateral ventricle and migrate to the OB through the rostral migratory stream. The majority of these newborn neurons differentiate into inhibitory interneurons, such as granule cells and periglomerular cells.

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.