A cytoarchitectonic study of the diencephalon of the tegu lizard, Tupinambis nigropunctatus

Abstract Nuclei in the hypothalamus, ventral thalamus, dorsal thalamus, epithalamus, and pretectum are described and named in the Tegu lizard, Tupinambis nigropunctatus. Many of the nineteen cell groups in the hypothalamus contain small, round cells located near the ventricle; two groups of magnocellular elements, nucleus supraopticus and nucleus paraventricularis, are also present. Of the eight cell groups in the ventral thalamus, nucleus geniculatus lateralis pars ventralis, located medial to the optic tract, is the most conspicuous. Six nuclei are described in the dorsal thalamus; nucleus rotundus and nucleus dorsolateralis anterior are very prominent. The epithalamus consists of medial and lateral habenular nuclei. In the pretectum, seven nuclear groups are recognized.