The nucleus raphe obscurus is one of the medullary raphe nuclei. It is located caudal to the

nucleus raphe magnus The nucleus raphe magnus (NRM) is one of the seven raphe nuclei. It is situated in the pons in the brainstem, just rostral to the nucleus raphe obscurus. The NRM receives afferent stimuli from the enkephalinergic neurons of the periaqueductal ...

. The nucleus raphe obscurus projects to the

cerebellar The cerebellum (: cerebella or cerebellums; Latin for 'little brain') is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as it or e ...

lobes VI and VII and to crus II along with the nucleus raphe pontis. The nucleus raphes obscurus has also been implicated in the modulation of the

hypoglossal nerve The hypoglossal nerve, also known as the twelfth cranial nerve, cranial nerve XII, or simply CN XII, is a cranial nerve that innervates all the extrinsic and intrinsic muscles of the tongue except for the palatoglossus, which is innervated b ...

. It has been observed that the

ablation Ablation ( – removal) is the removal or destruction of something from an object by vaporization, chipping, erosion, erosive processes, or by other means. Examples of ablative materials are described below, including spacecraft material for as ...

of this nucleus causes a change in the firing pattern of this

cranial nerve Cranial nerves are the nerves that emerge directly from the brain (including the brainstem), of which there are conventionally considered twelve pairs. Cranial nerves relay information between the brain and parts of the body, primarily to and f ...

. In addition, the nucleus raphe obscurus mediates

expiration Expiration or expiration date may refer to: Expiration Expiration may refer to: *Death *Exhalation of breath, breathing out * Expiration (options), the legal termination of an option to take an action *Shelf life, or the time after which a product ...

via the effect of

serotonin Serotonin (), also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter with a wide range of functions in both the central nervous system (CNS) and also peripheral tissues. It is involved in mood, cognition, reward, learning, ...

and depresses periodic synaptic potentials. It has also been shown that this nucleus stimulates gastrointestinal motor function; microinjections of 5-HT into the nucleus raphe obscurus increase gastric movement.

References

{{Authority control Medulla oblongata

See also

References