The motor nucleus of facial nerve is a collection of neurons in the brainstem that belong to the facial nerve. These lower motor neurons innervate the muscles of facial expression and the stapedius.
The nucleus is situated in the caudal portion of the ventrolateral pontine tegmentum. Its axons take an unusual course, traveling dorsally and looping around the abducens nucleus, then traveling ventrally to exit the ventral pons medial to the spinal trigeminal nucleus. These axons form the motor component of the facial nerve, with parasympathetic and sensory components forming the nervus intermedius.
The nucleus has a dorsal and ventral region, with neurons in the dorsal region innervating muscles of the upper face and neurons in the ventral region innervating muscles of the lower face.