A developmental window during which olfactory neurons of newborn mice can form a proper wiring map has been identified by researchers. They show that if incorrect neuronal connections are maintained after this period, renewing cells will also be mis-wired. The human nose expresses nearly 400 odorant receptors, which allow us to distinguish a large number of scents. In mice the number of odor receptors is closer to 1000. Each olfactory neuron displays only a single type of receptor and all neurons with the same receptors are connected to the same spot, a glomerulus, in the brain.