Abstract
We have identified occ1 as a gene enriched in the primary visual cortex (V1) of macaque monkeys. We have also reported that the occ1 mRNA expression in excitatory neurons of V1 is strongly downregulated by monocular deprivation (MD) by intraocular TTX injection in macaques, and that the V1-enriched expression pattern of occ1 is restiricted to primates among mammals. In the present study, we show that the expression patterns of occ1 mRNA were similar between macaques and mice, despite the distinct pattern in V1. Furthermore, we examined differences of activity-dependency in occ1 mRNA expression between macaques and mice, comparing those of immideate-early genes (IEGs), c-fos and zif268. MD dramatically reduced mRNA expression of occ1 and IEGs in macaque V1. The same treatment in mice decreased IEG expression both in the visual cortex and dLGN. The mRNA expression of occ1 in mouse visual cortices and dLGN was, however, scarcely affected by MD. Moreover, cochleotomy and olfactonomy neither affected occ1 mRNA expression in the cochlear nucleus nor in the olfactory bulb, respectively. These observations illustrated that whereas the strong activity-dependent regulation of IEG expression is common throughout regions and species, occ1 mRNA expression in primate V1 is evolutionarily unique. [J Physiol Sci. 2007;57 Suppl:S140]
