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Dental malocclusion stimulates neuromuscular circuits associated with temporomandibular disorders
Author(s) -
Liu Xin,
Zhang Chunkui,
Liu Qian,
Zhou Kaixiang,
Yin Nannan,
Zhang Hongyun,
Shi Minghong,
Liu Xiaodong,
Wang Meiqing
Publication year - 2018
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1111/eos.12579
Subject(s) - nucleus ambiguus , hypoglossal nucleus , medicine , biotinylated dextran amine , spinal trigeminal nucleus , nucleus , masseter muscle , neuroscience , anatomy , axon , chemistry , medulla oblongata , biology , nociception , central nervous system , receptor
Unilateral anterior crossbite ( UAC ) has been demonstrated to cause masseter hyperactivity via the periodontal trigeminal mesencephalic nucleus (Vme)–trigeminal motor nucleus circuit. Here, we studied activation of motor neurons of the facial nucleus ( VII ), hypoglossal nucleus ( XII ), nucleus ambiguus (Amb), and spinal nucleus of the accessory nerve ( SNA ) in rats with UAC via their similar connections with Vme. An anterograde tracer, biotinylated dextran amine ( BDA ), was injected into the Vme to identify the central axon terminals around the motor neurons of VII , XII , Amb, and SNA . The expression of vesicular glutamate transporter 1 ( VGLUT 1) in neurons of VII , XII , Amb, and SNA , and the expression of acetylcholinesterase ( AC hE) were measured in the stapedius, lingualis, palatopharyngeal, and sternocleidomastoid muscles. In BDA ‐treated rats, many BDA ‐labeled cell bodies in the Vme and terminals in VII , XII , Amb, and SNA were identified. Compared with control rats, rats with UAC showed higher expression of VGLUT 1 in these nuclei, and statistically significantly higher expression of AC hE in the stapedius, lingualis, and sternocleidomastoid muscles, but not in the palatopharyngeal muscle. These findings suggest that UAC activates orofacial, head, and cervical multimotor behaviors via connections between the Vme and the corresponding motor nuclei.