See habenula

Habenula

In neuroanatomy, habenula originally denoted the stalk of the pineal gland , but gradually came to refer to a neighboring group of nerve cells with which the pineal gland was believed to be associated, the habenular nucleus...

 for more detailed information.

The habenular nuclei comprise a small group of nuclei

Nucleus (neuroanatomy)

In neuroanatomy, a nucleus is a brain structure consisting of a relatively compact cluster of neurons. It is one of the two most common forms of nerve cell organization, the other being layered structures such as the cerebral cortex or cerebellar cortex. In anatomical sections, a nucleus shows up...

 that are part of the epithalamus

Epithalamus

The epithalamus is a dorsal posterior segment of the diencephalon which includes the habenula, the stria medullaris and the pineal body...

 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...

, situated at the posterior end of the thalamus

Thalamus

The thalamus is a midline paired symmetrical structure within the brains of vertebrates, including humans. It is situated between the cerebral cortex and midbrain, both in terms of location and neurological connections...

, on its upper surface.

The habenular nuclei are typically divided into:

• lateral habenular nucleus
• medial habenular nucleus

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...

 is attached to the brain in this region.

Nerve impulses

Action potential

In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and...

 from the habenular nuclei are transmitted to the septal nuclei

Septal nuclei

The septal area are structures that lie below the rostrum of corpus callosum in front of lamina terminalis , composed of medium-size neurons grouped into medial, lateral, and posterior groups...

 via the stria medullaris

Stria medullaris

The stria medullaris, also known as stria medullaris thalami, is a fiber bundle containing efferent fibers from the septal nuclei, lateral preoptico-hypothalamic region, and anterior thalamic nuclei to the habenula...

, which is found on the medial surface of the thalamus.

External links

• http://isc.temple.edu/neuroanatomy/lab/atlas/pdhn/