The oral pontine reticular nucleus, or rostral pontine reticular nucleus, is delineated from the

caudal pontine reticular nucleus The caudal pontine reticular nucleus or nucleus reticularis pontis caudalis is a portion of the reticular formation, composed of gigantocellular neurons. In rabbits and cats it is exclusively giant cells, however in humans there are normally size ...

. This nucleus tapers into the lower mesencephalic reticular formation and contains sporadic

giant cell A giant cell (also known as multinucleated giant cell, or multinucleate giant cell) is a mass formed by the union of several distinct cells (usually histiocytes), often forming a granuloma. Although there is typically a focus on the pathological ...

s. Different populations of the pontis oralis have displayed discharge patterns which coordinate with phasic movements to and from

paradoxical sleep Rapid eye movement sleep (REM sleep or REMS) is a unique phase of sleep in mammals and birds, characterized by random rapid movement of the eyes, accompanied by low muscle tone throughout the body, and the propensity of the sleeper to dream viv ...

. From this information it has been implied that the n.r. pontis oralis is involved in the mediation of changing to and from

REM sleep Rapid eye movement sleep (REM sleep or REMS) is a unique phase of sleep in mammals and birds, characterized by random rapid movement of the eyes, accompanied by low muscle tone throughout the body, and the propensity of the sleeper to dream viv ...

.Dergacheva OIu et al. Impulse activity of neurons in the nucleus pontis oralis in cats during sleep--wakefulness cycle. Ross Fiziol Zh Im I M Sechenova. 2002 Dec;88(12):1530-7.

References

Pons Neuroscience of sleep {{Neuroanatomy-stub