title: Jaw-opening and -closing premotoneurons in the nucleus of the solitary tract making contacts with laryngeal and pharyngeal afferent terminals in rats.
abstract: This study clarified the neural mechanisms underlying jaw movements in pharyngolaryngeal reflexes such as swallowing in rats. After retrograde tracer injections into the ventromedial division (Vmovm) of the trigeminal motor nucleus (Vmo) containing jaw-opening (JO) motoneurons or into the dorsolateral division (Vmodl) of Vmo containing jaw-closing (JC) motoneurons, JO and JC premotoneurons were labeled with an ipsilateral predominance in the medial and intermediate subnuclei of the rostrocaudal middle two-thirds of the nucleus of the solitary tract (Sol); JC premotoneurons were also in the lateral subnucleus of Sol. After anterograde tracer injections into the Sol, axons were labeled with an ipsilateral predominance in the Vmovm and Vmodl, prominently in the ipsilateral Vmovm. After transganglionic tracer applications to the superior laryngeal nerve (SLN) or the cervical trunk of the glossopharyngeal nerve (GpN-ct), labeled afferents were seen in the medial, intermediate, lateral and interstitial subnuclei of Sol at the rostral three-fourths of Sol, indicating considerable overlap with the JO and JC premotoneurons in the Sol. Double labeling experiments demonstrated contacts between the afferent terminals and the JO and JC premotoneurons. The present study has for the first time revealed the differential distribution of JO and JC premotoneurons in the Sol and features of their projections from the Sol, as well as their connections with SLN and GpN-ct afferent inputs. The JO and JC premotoneurons in the Sol may play an important role in generation and organization of jaw movements in pharyngolaryngeal reflexes evoked by SLN and GpN-ct inputs, such as swallowing.
authors.affiliation: Department of Oral Anatomy and Neurobiology, Graduate School of Dentistry, Osaka University, Osaka 565-0871, Japan; Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University, Osaka 565-0871, Japan.
authors.forename: Ayaka
authors.initials: A
authors.lastname: Oka
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Rieko
authors.initials: R
authors.lastname: Takeda
authors.forename: Haruka
authors.initials: H
authors.lastname: Ohara
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Sato
authors.forename: Fatema
authors.initials: F
authors.lastname: Akhter
authors.forename: Tahsinul
authors.initials: T
authors.lastname: Haque
authors.forename: Takafumi
authors.initials: T
authors.lastname: Kato
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Sessle
authors.forename: Kenji
authors.initials: K
authors.lastname: Takada
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yoshida
mesh_terms: D000344:Afferent Pathways / Q000166:cytology; D000818:Animals; D005930:Glossopharyngeal Nerve / Q000166:cytology; D007568:Jaw / Q000294:innervation*; D007823:Laryngeal Nerves / Q000166:cytology; D008297:Male; D009046:Motor Neurons / Q000166:cytology*; D017729:Presynaptic Terminals / Q000648:ultrastructure*; D051381:Rats; D017208:Rats, Wistar; D017552:Solitary Nucleus / Q000033:anatomy & histology / Q000166:cytology*; D014278:Trigeminal Nuclei / Q000166:cytology*
keywords: AP; Amb; BDA; CTb; Cu; ECu; FG; Fluorogold; GpN-ct; Gr; IO; JC; JO; Jaw movement; PB; PBS; PaV; Pb; Pbm; Pharyngolaryngeal reflex; RmJO; SLN; SO; Sol; Solitary tract nucleus; Swallowing; Trigeminal; VII; Vc; Ve; Vi; Vidm; Vint; Vivl; Vmes; Vmo; Vmodl; Vmovm; Vodm; Vovl; Vp; Vsup; Vtr; X; XII; area postrema; biotinylated dextranamine; cervical trunk of the glossopharyngeal nerve; cholera toxin B subunit; cuneate nucleus; dorsal nucleus of the vagus; dorsolateral division of the Vmo; dorsomedial part of the Vi; dorsomedial part of the trigeminal oral subnucleus; external cuneate nucleus; facial nucleus; gracile nucleus; hypoglossal nucleus; im; im-Sol; inferior olive; intermediate subnucleus of the Sol; interstitial subnucleus of the Sol; intertrigeminal region; is; is-Sol; jaw-closing; jaw-opening; la; la-Sol; lateral subnucleus of the Sol; me; me-Sol; medial part of the Pb; medial subnucleus of the Sol; nucleus ambiguus; nucleus of the solitary tract; parabrachial nucleus; paratrigeminal nucleus; phosphate buffer; phosphate-buffered saline; py; pyramid; pyramidal decussation; pyx; reticular formation medial to JO component of the Vmo; scp; superior cerebellar peduncle; superior laryngeal nerve; superior olive; supratrigeminal nucleus; trigeminal caudal subnucleus; trigeminal interpolar subnucleus; trigeminal mesencephalic nucleus; trigeminal motor nucleus; trigeminal principal nucleus; trigeminal spinal tract; ventrolateral part of the Vi; ventrolateral part of the trigeminal oral subnucleus; ventromedial division of the Vmo; vestibular nucleus