part of diencephalon development subthalamus development biological_process The process whose specific outcome is the progression of the subthalamus over time, from its formation to the mature structure. The subthalamus is the anterior part of the diencephalon that lies between the thalamus, hypothalamus, and tegmentum of the mesencephalon, including subthalamic nucleus, zona incerta, the fields of Forel, and the nucleus of ansa lenticularis. ventral thalamus development GO:0021539 anatomical structure development