Where is the habenular nuclei located?

The habenular nuclei are located just anterior to the pineal gland and consist of a large lateral nucleus and a small medial nucleus (Figs. 15.2 and 15.15). Both nuclei contribute axons to the habenulointerpeduncular tract (fasciculus retroflexus), which terminates in the midbrain interpeduncular nucleus.

What is the habenular commissure?

The habenular commissure is a white matter tract connecting the two habenular nuclei and the internal medullary laminae 1. …

How many habenular nuclei are there?

two
1998; Butler & Hodos 2005). In mammals, the habenular complex comprises two separate nuclei on each side: the ‘medial’ (MHb) and ‘lateral’ (LHb) habenulae. The LHb is further subdivided into principal medial and lateral subdivisions.

What is the best definition of habenula?

1 : trigonum habenulae. 2 : either of two nuclei of which one lies on each side of the pineal gland under the corresponding trigonum habenulae, is composed of two groups of nerve cells, is connected to its contralateral counterpart by the habenular commissure, and forms a correlation center for olfactory stimuli.

What is epithalamus?

The epithalamus is a small region of the diencephalon consisting of the pineal gland, habenular nuclei, and stria medullaris thalami. The pineal gland contains no true neurons, only glial cells. The stria medullaris connects fibers from the habenular nuclei with the limbic system.

What is the function of habenular nucleus?

Anatomical terms of neuroanatomy The habenular nuclei (habenula is Latin for “little rein”) acts as a regulator of key central nervous system neurotransmitters, connecting the forebrain and midbrain within the epithalamus.

What does the habenular nucleus do?

The habenular nuclei (habenula is Latin for “little rein”) act as regulators of key central nervous system neurotransmitters, connecting the forebrain and midbrain within the epithalamus.

Is the epithalamus?

The epithalamus is a posterior segment of the diencephalon. The epithalamus includes the habenula and their interconnecting fibers the habenular commissure, the stria medullaris and the pineal gland. The function of the epithalamus is to connect the limbic system to other parts of the brain.

What is the function of the pineal gland?

The main function of the pineal gland is to receive and convey information about the current light-dark cycle from the environment and, consequently produce and secrete melatonin cyclically at night (dark period).

What is the function of red nucleus in short?

The red nucleus is a large structure located centrally within the tegmentum that is involved in the coordination of sensorimotor information. Crossed fibres of the superior cerebellar peduncle (the major output system of the cerebellum) surround and partially terminate in the red nucleus.

Where does the habenular nucleus send its efferents?

The medial habenular nucleus projects its efferents to the interpeduncular nucleus (IPN) through the habenulopeduncular tract (or fasciculus retroflexus ), whereas the lateral habenular nucleus sends its efferents directly to the median and dorsal raphe, substantia nigra (SN), and the ventral tegmental area (VTA).

Where does the habenula receive efferent fibres from?

Habenula is derived from habena: Latin for a bridle. Receiving input from the olfactory tubercles, thalamus and hypothalamus, the habenula nuclei send efferent fibres via the fasciculus retroflexus to the interpeduncular nuclei of the midbrain that lie between the cerebral peduncles.

Where is the habenulae located in the thalamus?

The medial and lateral habenulae or medial and lateral habenular nuclei are situated in relation to a triangular depression in the wall of the third ventricle called the habenular trigone. It lies in relation to the dorsomedial part of the thalamus.

What are the functions of the efferent ductules?

The Efferent Ductules: Structure and Functions. Robaire and Hermo (1988) focused on efferent ductules of the rat and gave detailed morphology of the two epithelial cell types, ciliated and nonciliated. They also provided initial discussions of the major function associated with these ductules, namely fluid reabsorption.