Region in the ventral telencephalon, prominent in rodents, but present in all mammals, consisting of a laminated cortical part and the cap/hilus region. It is traditionally viewed as part of the olfactory cortex but recognized by some as having a striatal character. According to many authors, the structure of the OT transitions from cortical like to striatal like along the lateral medial axis. (Maryann Martone) [ ]