Dopaminergic (DA) inhibitory interneurons in the olfactory bulb (OB) act at a crucial point in the early olfactory pathway, modulating the gain of the first synapse from the nose to the brain. DA neurons are extremely plastic cells, capable of regulating their shape and function in an activity-dependent manner, and even of regenerating throughout life. Long-believed to be a homogeneous population, recent evidence has instead uncovered a striking heterogeneity in their shape, function, and developmental profile – including their axonal phenotype and ability to undergo adult neurogenesis. Moreover, we have recently shown that DA neurons subtypes differ in their plastic responses to changes in olfactory inputs. Indeed, only a subclass of axon-bearing/non-regenerating DA cells respond to brief olfactory deprivation by implementing structural plasticity at their axon initial segments, and intrinsic plastic changes that result in decreased excitability. Conversely, ongoing work in our lab indicates that while anaxonic/regenerating DA cells fail to modify their structure or intrinsic excitability, they employ multiple synaptic plasticity mechanisms to respond to the same brief sensory deprivation. Interestingly, excitatory neurons in the OB circuit – both projection cells and local interneurons - display substantially fewer deprivation-induced plastic changes. These findings support the hypothesis that modulation of inhibition may be a fast-acting mechanism employed by circuits to rapidly adapt and fine-tune sensory processing in the face of continually fluctuating inputs. Future work in our lab aims to uncover how such different and cell-type targeted activity-dependent plastic changes are employed to generate appropriate neuronal outputs at the network and behavioural level.