PT  - JOURNAL ARTICLE
AU  - Elisa Galliano
AU  - Eleonora Franzoni
AU  - Marine Breton
AU  - Annisa N. Chand
AU  - Darren J. Byrne
AU  - Venkatesh N. Murthy
AU  - Matthew S. Grubb
TI  - Embryonic and postnatal neurogenesis produce functionally distinct subclasses of dopaminergic neuron
AID  - 10.1101/196006
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 196006
4099  - http://biorxiv.org/content/early/2018/03/26/196006.short
4100  - http://biorxiv.org/content/early/2018/03/26/196006.full
AB  - Most neurogenesis in the mammalian brain is completed embryonically, but in certain areas the production of neurons continues throughout postnatal life. The functional properties of mature postnatally-generated neurons often match those of their embryonically-produced counterparts. However, we show here that in the olfactory bulb (OB), embryonic and postnatal neurogenesis produce functionally distinct subpopulations of dopaminergic (DA) neurons. We define two subclasses of OB DA neuron by the presence or absence of a key subcellular specialisation: the axon initial segment (AIS). Large AIS-positive axon-bearing DA neurons are exclusively produced during early embryonic stages, leaving small anaxonic AIS-negative cells as the only DA subtype generated via adult neurogenesis. These populations are functionally distinct: large DA cells are more excitable, yet display weaker and – for certain long-latency or inhibitory events – more broadly-tuned responses to odorant stimuli. Embryonic and postnatal neurogenesis can therefore generate distinct neuronal subclasses, placing important constraints on the functional roles of adult-born neurons in sensory processing.