In rodents, projectionsfrom OSNsto the olfactory bulb are
chemotopically organized by more than 1200 genes.
Specifically, OSNs expressing the same odorant receptor
project to the same glomeruli in the olfactory bulb
[8,23,24]. The apical dendrites of individual mitral cells
form synapses with OSN axons within a glomerulus. Mitral
cells, in turn, project to various cortical and sub-cortical
structures [25,26
]. Therefore, one might hypothesize that
the cortical connections of mitral cells would mirror the