The 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. (Thalamic fasciculus visible but not labeled, as red line from GPi to THA.)
The thalamic fasciculus is a component of the subthalamus. It is sometimes considered synonymous with "field H1 of Forel". Nerve fibres form a composite bundle containing cerebellothalamic (crossed) and pallidothalamic (uncrossed) fibres that is insinuated between the thalamus and zona incerta.