Nucleus raphe obscurus
Encyclopedia
The nucleus raphes obscurus, despite the implications of its name, has some very specific functions and connections of afferent and efferent nature. The nucleus raphes obscurus projects to the cerebellar
lobes VI and VII and to crus II along with the nucleus raphes pontis .
This so called nucleus raphes obscurus has also been implicated in the modulation of the hypoglossal nerve
. It has been observed that the ablation
of this nucleus causes a change in the firing pattern in the XII nerve .
In addition, the nucleus raphes obscurus mediates expiration
via the effect of serotonin
and depresses periodic synaptic potentials . It has also been shown that this nucleus stimulates gastrointestinal motor function; microinjections of 5-HT into the nucleus raphes obscurus increase gastric movement .
Cerebellum
The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
lobes VI and VII and to crus II along with the nucleus raphes pontis .
This so called nucleus raphes obscurus has also been implicated in the modulation of the hypoglossal nerve
Hypoglossal nerve
The hypoglossal nerve is the twelfth cranial nerve , leading to the tongue. The nerve arises from the hypoglossal nucleus and emerges from the medulla oblongata in the preolivary sulcus separating the olive and the pyramid. It then passes through the hypoglossal canal...
. It has been observed that the ablation
Ablation
Ablation is removal of material from the surface of an object by vaporization, chipping, or other erosive processes. This occurs in spaceflight during ascent and atmospheric reentry, glaciology, medicine, and passive fire protection.-Spaceflight:...
of this nucleus causes a change in the firing pattern in the XII nerve .
In addition, the nucleus raphes obscurus mediates expiration
Expiration
Expiration is an independent feature film written, directed and starring Gavin Heffernan. It was the winner of the Grand Jury Prize and Best Film at the Canadian Filmmakers' Festival....
via the effect of serotonin
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...
and depresses periodic synaptic potentials . It has also been shown that this nucleus stimulates gastrointestinal motor function; microinjections of 5-HT into the nucleus raphes obscurus increase gastric movement .