Limbic system-associated membrane protein (LAMP) is a cell adhesion molecule expressed mainly in the limbic system and it plays a role in axonal patterning during brain development. LAMP was originally found in mammals, but our previous study on LAMP distribution in pigeon brain (Yamamoto & Reiner, SFN 31st annual meeting abstract, 2001) showed that LAMP is present even in non-mammalian species. In this study, we performed immunohistochemistry for LAMP in rats, ground squirrels, pigeons, and zebra finches to compare visual and auditory nuclei in the thalamus and midbrain. As in previous studies, LAMP labeling was mainly found in midline limbic structures in all species, but there were several non-limbic visual structures that showed LAMP labeling. In the midbrain, both the avian optic tectum and upper layers of the mammalian superior colliculus, which contain comparable cell types, were LAMP-rich. In the thalamus, the avian nu rotundus (Rt), which receives afferent projections from the optic tectum, was ri...