Otx2 homeoprotein is well-known as an essential morphogen or 'head organizer' during embryonic development. Our previous studies showed that postnatal recapture of this homeoprotein was required for the cortical plasticity. Otx2 expression is localized into retina, lateral geniculate nucleus and superior colliculus along the visual pathway. Experience-dependent transfer of Otx2 to the primary visual cortex activates the plasticity for binocular vision (Sugiyama et al., 2008). Interestingly, Otx2 transcripts were also observed in several regions of rat brain at postnatal day 13 (P13) (Franz et al,. 1994), then that the protein was distributed throughout brain areas as well as the visual pathway. So, it yet remains an open question whether Otx2 is generally reused for postnatal brain development and plasticity. To reveal exact sites of this homeoprotein synthesis, we first conducted comprehensive expression analysis using the lacZ knock-in mice at Otx2 locus. In these mice, Otx2 expression area can be detected by X-gal staining through whole brain sections. Analysis from adult slices reveals the novel sites of Otx2 synthesis, which include three major functional groups as the following: group 1 for dopaminergic nuclei, group 2 for emotion-related nuclei, group 3 for sensory or motion-related regions. The expression was not detected in limbic regions like hippocampus, amygdala and striatum, where observed at P13 rat. Thus, Otx2 expression is postnatally controlled in the distinct cell types and neuronal circuitries, where this homeoprotein may be involved in their functional development.