Adult Neurogenesis Produces Neurons with Unique GABAergic Synapses in the Olfactory Bulb.

Neuronal regeneration occurs naturally in a few restricted mammalian brain regions, but its functional significance remains debated. Here we search for unique features in the synaptic outputs made by adult-born granule cell interneurons in the mouse olfactory bulb using optogenetic targeting of specific neuronal ages. We find that adult-born interneurons are resistant to presynapticGABA_B-mediated depression of GABA release compared with interneurons born just after birth that exhibit strong GABA_B neuromodulation. Correlated with this functional change, we found altered localization of the GABA_BR1 protein within adult-born granule cells. These results suggest that adult neurogenesis produces a population of functionally unique GABAergic synapses in the olfactory bulb. [ABSTRACT FROM AUTHOR]