ansa lenticularis ansa lenticularis the ansa lenticularis (ansa lentiformis in older texts) is a part of the brain, making up the superior layer of the substantia innominata. its fibers, derived from the medullary lamina of the lentiform nucleus, pass medially to end in the thalamus and subthalamic region, while others are said to end in the tegmentum and red nucleus. it is classified by neuronames as part of the subthalamus. ansa lenticularisthe image shows dopaminergic pathways of the human brain in normal condition (left) and parkinsons disease (right). red arrows indicate suppression of the target, blue arrows indicate stimulation of target structure. (ansa lenticularis visible but not labeled, as red line from gpi to tha.)detailsidentifierslatinansa lentiformisneuronames444neurolex idnlx_87326ta98a14.1.08.663 a14.1.09.520 a14.1.08.665ta25751fma62070anatomical terms of neuroanatomy