Slide 14: Transition between the Mesencephalon and Diencephalon
Corticospinal Tract fibers (CST)
Substantia Nigra (SN)
Red Nucleus (RN)
Cerebello-thalamic fibers (CBTh)
Central Tegmental Tract (CTT)
Hypothalamo-Autonomic Tract (HAT)
Medial Lemniscus (ML)
Spinothalamic Tract (STT)
Medial Geniculate (MG)
Brachium of the Inferior Colliculus (BIC)
Optic Tract (OT, best seen on right)
Posterior Commissure (PC)
Cerebral Aqueduct just beneath the Posterior Commissure
Pretectal Area (PTA)
Pulvinar Nucleus of the thalamus (PUL)
The Medial Geniculate is a major relay station in the central auditory pathway, receiving the terminations of the Brachium of the Inferior Colliculus and projecting to the Auditory Cortex in the temporal lobe.
The Lateral Geniculate is a major relay station in the central visual pathway, receiving terminations from the Optic Tract and projecting via the Optic Radiations to the Visual Cortex in the occipital lobe.
The Pretectal Area is a vital link in the pupillary light reflex.
The Pulvinar Nucleus of the thalamus receives a large input from the Optic Tract.