Site Map
Home Page
External Morphology
Internal Architecture
Specialized Body Features
Behavioral Repertoire
Brain-Behavior Correlates
Ecological Adaptions
Related Websites
Contact Us


The Midbrain comprises the rostral portions of the brain stem. It is in front of the medulla and lies beneath the posterior portion of the cerebrum, and portions of its dorsal surface (superior and inferior colliculi) lie in front of the cerebellum. The accompanying pictures (sagittal section and ventral view) reveal its position, and arrangement of its parts.

On the top of the midbrain sits the superior colliculus (a visual center) rostrally, and the inferior colliculus (an auditory center) caudally just in front of the cerebellum.

On its ventral surface can be seen the two cerebral peduncles which contain the fiber tracts from the forebrain which course caudally carrying information into the midbrain, the medulla, cerebellum and spinal cord.

The pons is a major protuberance lying at the caudal margin of the midbrain. The three motor nerves to the muscles of the eyes originate from motor nuclei in the midbrain. The midbrain also contains a large number of cellular groups or nuclei, as well fiber tracts and bundles. Below are displayed a number of cross sections through the Midbrain so that viewers can appreciate the complexity and diversity of architectural formations that exist within the rostral portion of the brainstem.

We present here a list of the many identified nuclear entities which lie within the midbrain portion of the brainstem. This list utilizes the nomenclature proposed in the Atlas of the brainstem by Alvin Berman.

Rostral Brainstem

  • Periaquaductal gray

  • Retroflex bundle

  • Ventral tegmental area

  • Zona incerta

  • Fields of Forel

  • Substantia nigra, compact and reticular portions

  • Nucleus of Darkschewitz

  • Central tegmental field

  • Interstitial nucleus of Cajal

  • Red nucleus

  • Substantia nigra (reticular, lateral, compact)

  • Nucleus of the accessary optic tract

  • Edinger-Westphal nucleus

  • Rostral linear nucleus

  • Interfascicular nucleus

  • Central interpeduncular nucleus

  • Oculomotor nucleus (3)

  • Trochlear nucleus (4)

  • Mesencephalic motor nucleus. (5)

  • Medial longitudinal fasciculus

  • Retrorubral nucleus
  • Pretectal nucleus, medial

  • Pretectal nucleus, olivary

  • Pretectal nucleus, anterior

  • Pretectal nucleus, posterior

  • Superior colliculus ( superficial, intermediate, deep)

  • Nucleus of posterior commissure

  • Nucleus of optic tract

Caudal Brainstem
  • Pons (dorsal, lateral, rostral, medial, dorsolateral)

  • Central linear nucleus

  • Interpeduncular complex (inner, outer, posterior, paramedian, apical)

  • Parabigeminal nucleus

  • Dorsal nucleus of raphe (medial, lateral)

  • Brachium conjunctivum, decussation

  • Marginal nucleus of the brachium conjunctivum

  • Inferior colliculus (external, central, pericentral, commissural, posterior)

  • Sagulum nucleus

  • Ventral nucleus. of the lateral lemniscus

  • Dorsal nucleus. of the lateral lemniscus

  • Superior central nucleus.

  • Tegmental reticular (central, pericentral) nucleus

  • Ventral tegmental nucleus

  • Dorsal tegmental nucleus (pericentral, dorsal, accessory)

  • nucleus. incertus

  • nucleus. caeruleus

  • Oculomotor nucleus (3)

  • Trochlear nucleus (4)

  • Cuneiform nucleus

  • Paralemniscal tegmental field

  • Kolliker-Fuse nucleus



External Morphology | Internal Architecture | Specialized Body Features | Behavioral Repertoire
Brain - Behavioral Correlates | Ecological Adaptations | Evolution | Related Websites | Contact Us
Personnel | References |