Dorsal thalamic nuclei in Caiman crocodilus.

In Caiman crocodilus, identification of nuclei that comprise the dorsal thalamus was determined by: injections of retrograde tracers into cortex/pallium; injections of retrograde tracers into the noncortical telencephalon; and injections of anterograde tracers into thalamic nuclei. With the exception of nucleus dorsolateralis anterior, which has bilateral projections, all other dorsal thalamic nuclei send axons to terminate in the ipsilateral telencephalon. Nuclei that only projected to cortex/pallium were: dorsolateralis anterior; diagonalis; and dorsal geniculate. Neuronal aggregates that send axons that terminated in the dorsolateral area (dorsal ventricular ridge) included: rotundus; reuniens pars centralis and pars diffusa; medialis complex posterior; posterocentralis; and area ventrolateralis. Medialis complex anterior axons ended in the ventrolateral area (basal ganglia). Nucleus dorsomedialis projected to both cortex/pallium and the dorsolateral area. Based on the locus of telencephalic termination and fiber trajectory from the dorsal thalamus, nuclei of the dorsal thalamus were divided into several groups.