The parvocellular reticular nucleus is part of the brain

Brain

The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

 located dorsolateral to the nucleus reticularis pontis caudalis.

The dorsal portion of the reticular nucleus has been shown to innervate the mesencephalic trigeminal nucleus and its surrounding area.

Also, it projects to the facial nucleus, hypoglossal nucleus

Hypoglossal nucleus

The hypoglossal nucleus is a cranial nerve nucleus, and it extends the length of the medulla, and being a motor nucleus, is close to the midline...

 and parabrachial nucleus

Parabrachial nucleus

The parabrachial nucleus is a region in the pons human brain that is related to the ascending reticular activating system . It can be subdivided into the lateral parabrachial nucleus and the medial parabrachial nucleus...

 along with parts of the caudal parvocellular reticular formation.

This nucleus is also involved in expiration

Exhalation

Exhalation is the movement of air out of the bronchial tubes, through the airways, to the external environment during breathing....

 with a part of the gigantocellular nucleus

Gigantocellular nucleus

The gigantocellular nucleus, as the name indicates, is mainly composed of the so called giant neuronal cells.This nucleus has been known to innervate the caudal hypoglossal nucleus, and responds to glutamateric stimuli....

.