Habenular commissure

The habenular commissure is a white matter tract connecting the two habenular nuclei and the internal medullary laminae . Whilst the exact role of the habenular commissure is unknown, the habenular nuclei play an important role in influencing how the brain responds to a variety of stimuli, including anxiety, pain, reward, stress, and sleep .

Gross anatomy

The habenular commissure is located in the superior lamina of the stalk of the pineal gland . The posterior commissure, located slightly inferiorly to the habenular commissure, is located in the inferior stalk of the pineal gland . The habenular commissure, along with the pineal gland, posterior commissure, and trigone habenulae comprise the epithalamus .

Radiographic features

The habenular commissure is often noted to be calcified on plain skull radiographs and CT imaging . In a study of 1000 consecutive patients who obtained both skull radiographs and CT scans, the habenular commissure was noted to be calcified in 13% of radiographs and 15% of CT scans .

Related pathology

The effect of isolated damage to the habenular commissure is unknown, although ablation of the habenular nuclei has been noted to cause impairments in metabolism, endocrine function, and thermal regulation .