Interconnections between the pretectum and visual thalamus in reptiles, Caiman crocodilus

Interconnections between the visual thalamus and the pretectum were investigated in one species of reptiles, Caiman crocodilus, by injections of horseradish peroxidase into nucleus rotundus. Nucleus pretectalis was identified as a major target of rotundal efferents as well as a significant input to nucleus rotundus. The presence of a pretectal nucleus with neural connections and topographic location similar to nucleus pretectalis of Caiman has been described in lizards and pigeons. Taken together, these observations suggest that this pretectal nuclear group and its associated fiber path may be a feature common to all non-mammalian amniotes.