Habenular commissure
Encyclopedia
The habenular commissure, is a brain commissure
(a band of nerve fibers) situated in front of the pineal gland
that connects the habenular nuclei
on both sides of the diencephalon
.
The habenular commissure is part of the trigonum habenulæ (a small depressed triangular area situated in front of the superior colliculus and on the lateral aspect of the posterior part of the tænia thalami). The trigonum habenulæ also contains groups of nerve cells termed the ganglion habenulæ. Fibers enter the trigonum habenulæ from the stalk of the pineal gland
, and the habenular commissure. Most of the trigonum habenulæ's fibers are, however, directed downward and form a bundle, the fasciculus retroflexus of Meynert, which passes medial to the red nucleus
, and, after decussating with the corresponding fasciculus of the opposite side, ends in the interpeduncular nucleus
.
Commissure
A commissure is the place where two things are joined. The term is used especially in the fields of anatomy and biology.In anatomy, commissure refers to a bundle of nerve fibers that cross the midline at their level of origin or entry .* The most common usage of the term refers to the brain's...
(a band of nerve fibers) situated in front of the pineal gland
Pineal gland
The pineal gland is a small endocrine gland in the vertebrate brain. It produces the serotonin derivative melatonin, a hormone that affects the modulation of wake/sleep patterns and seasonal functions...
that connects the habenular nuclei
Habenular nuclei
The habenular nuclei comprise a small group of nuclei that are part of the epithalamus of the diencephalon, situated at the posterior end of the thalamus, on its upper surface.The habenular nuclei are typically divided into:* lateral habenular nucleus...
on both sides of the diencephalon
Diencephalon
The diencephalon is the region of the vertebrate neural tube which gives rise to posterior forebrain structures. In development, the forebrain develops from the prosencephalon, the most anterior vesicle of the neural tube which later forms both the diencephalon and the...
.
The habenular commissure is part of the trigonum habenulæ (a small depressed triangular area situated in front of the superior colliculus and on the lateral aspect of the posterior part of the tænia thalami). The trigonum habenulæ also contains groups of nerve cells termed the ganglion habenulæ. Fibers enter the trigonum habenulæ from the stalk of the pineal gland
Pineal gland
The pineal gland is a small endocrine gland in the vertebrate brain. It produces the serotonin derivative melatonin, a hormone that affects the modulation of wake/sleep patterns and seasonal functions...
, and the habenular commissure. Most of the trigonum habenulæ's fibers are, however, directed downward and form a bundle, the fasciculus retroflexus of Meynert, which passes medial to the red nucleus
Red nucleus
The red nucleus is a structure in the rostral midbrain involved in motor coordination. It comprises a caudal magnocellular and a rostral parvocellular part.-Function:...
, and, after decussating with the corresponding fasciculus of the opposite side, ends in the interpeduncular nucleus
Interpeduncular nucleus
The Interpeduncular nucleus is a unpaired, ovoid cell group at the base of the midbrain tegmentum. It is located in the mesencephalon below the interpeduncular fossa...
.
External links
- NIF Search - Habenular commissure via the Neuroscience Information FrameworkNeuroscience Information FrameworkThe Neuroscience Information Framework is a repository of global neuroscience web resources, including experimental, clinical, and translational neuroscience databases, knowledge bases, atlases, and genetic/genomic resources.-Description:...