Odor enrichment increases interneurons responsiveness in spatially defined regions of the olfactory bulb correlated with perception.

Odor enrichment enhances rats' ability to discriminate between chemically similar odorants. We show here that this modulation of olfactory perception is accompanied by increases in the density of local inhibitory interneuron expressing Zif268 in response to olfactory stimuli. These changes depend on the overlap of the olfactory bulb activation patterns induced by the enrichment odorants with those induced by the testing odorants, in a manner similar to changes in perception. Moreover, we show that enrichment leads to an alteration of the pattern of Zif268 expression, dependent on the odors used for the enrichment indicating a restructuring of odor representation in the olfactory bulb.