What is the habenula?
The habenula is a pair of small nuclei located above the thalamus at its posterior end close to the midline (Fig. It is regarded as part of the epithalamus, which includes the pineal body and the habenula. In many vertebrates, the habenula is divided into the medial habenula (MHb) and the lateral habenula (LHb).
What is medial habenula?
The habenula is a complex nucleus composed of lateral and medial subnuclei, which connect between the limbic forebrain and midbrain. Although the medial habenula is the source of one of the major cholinergic pathways in the brain, relatively few studies have been conducted to understand its roles.
What is fasciculus Retroflexus?
The fasciculus retroflexus is the primary habenular output from the habenula to the midbrain and governs release of glutamate onto gabaergic cells in the rostromedial tegmental nucleus (RMTg) and onto the interpeduncular nucleus. Through this process, the habenula controls dopamine levels in the striatum.
What does the Interpeduncular nucleus do?
Function. The Interpeduncular nucleus is thought to have a broad inhibitory effects on many other brain regions. IPN activity is linked with decreased dopamine release and utilization from dopamine producing regions. The Interpeduncular nucleus is implicated with a role in the regulation of Rapid eye movement sleep.
What is the function of the Interpeduncular fossa?
The interpeduncular fossa may be incised to resect anteriorly located lesions that are medial to the oculomotor nerve and can serve as an alternative to the anterior mesencephalic safe entry zone (i.e., perioculomotor safe entry zone) for resection of ventromedial midbrain lesions.
What is the best definition of Habenula?
Anatomy. a narrow bandlike structure, as the stalk attaching the pineal gland to the thalamus.
What is the best definition of habenula?
What is stria Medullaris?
The stria medullaris is a fiber bundle containing efferent fibers from the septal nuclei, lateral preoptico-hypothalamic region, and anterior thalamic nuclei to the habenula. It forms a horizontal ridge on the medial surface of the thalamus.
Where is the Interpeduncular nucleus?
midbrain
The interpeduncular nucleus (IPN) is an unpaired, ovoid cell group at the base of the midbrain tegmentum. It is located in the mesencephalon below the interpeduncular fossa.
Where is the Interpeduncular fossa?
Interpeduncular fossa is a somewhat lozenge-shaped area of the base of the brain, limited in front by the optic chiasma, behind by the antero-superior surface of the pons, antero-laterally by the converging optic tracts, and postero-laterally by the diverging cerebral peduncles.
What is Edinger Westphal nucleus?
The Edinger-Westphal nucleus is a small parasympathetic motor nucleus in the midbrain and one of the two nuclei for the oculomotor nerve. It is one of the cranial nerve nuclei.