In:
PLOS ONE, Public Library of Science (PLoS), Vol. 17, No. 11 ( 2022-11-28), p. e0278205-
Abstract:
In studies of vestibulo-ocular reflex (VOR), the horizontal VOR circuit is much clearer than vertical-torsional VOR. The circuit and mechanism of gravity-related vertical-torsional VOR is probably weak. “Somatosensory vestibular interaction” is a known extra source to facilitate VOR, and cervico-ocular reflex is a representative for torsional VOR compensation. Whereas, how the cervical afferents finally reach the oculomotor system is less documented. Actually, when the head tilts, which generates cervico-ocular reflex, not only the neck muscle is activated, but also the jaw muscle is stretched by gravity dragged mandible and/or tissue-muscle connection between the mandible and clavicle. We have previously identified a projection from the jaw muscle afferent mesencephalic trigeminal nucleus (Vme) neurons to oculomotor nuclei (III/IV) and their premotor neurons in interstitial nucleus of Cajal (INC)–a well-known pre-oculomotor center manipulating vertical-torsional eye movements. We hypothesized that these projections may interact with vestibulo-ocular signals during vertical-torsional VOR, because effects of gravity on jaw muscles and bones has been reported. Thus, we injected different anterograde tracers into the Vme and medial vestibular nucleus (MVN)—the subnuclear area particularly harboring excitatory vestibulo-ocular neurons, and immunostained III/IV motoneurons. Retrograde tracer was injected into the III in the same animals after dual anterograde tracers’ injections. Under confocal microscope, we observed the Vme and MVN neuronal endings simultaneously terminated onto the same III/IV motoneurons and the same INC pre-oculomotor neurons. We consider that jaw muscle proprioceptive Vme neurons projecting to the III/IV and INC would sense spindle activity if the jaw muscle is stretched by gravity dragged mandible or connection between mandible and clavicle during head rolling. Therefore, the convergent innervation of the Vme and MVN neurons onto the oculomotor and pre-oculomotor nuclei would be a neuroanatomic substrate for interaction of masticatory proprioception with the vestibulo-ocular signals upon the oculomotor system during vertical-torsional VOR.
Type of Medium:
Online Resource
ISSN:
1932-6203
DOI:
10.1371/journal.pone.0278205
DOI:
10.1371/journal.pone.0278205.g001
DOI:
10.1371/journal.pone.0278205.g002
DOI:
10.1371/journal.pone.0278205.g003
DOI:
10.1371/journal.pone.0278205.g004
DOI:
10.1371/journal.pone.0278205.g005
DOI:
10.1371/journal.pone.0278205.g006
DOI:
10.1371/journal.pone.0278205.t001
DOI:
10.1371/journal.pone.0278205.s001
DOI:
10.1371/journal.pone.0278205.s002
DOI:
10.1371/journal.pone.0278205.r001
DOI:
10.1371/journal.pone.0278205.r002
DOI:
10.1371/journal.pone.0278205.r003
DOI:
10.1371/journal.pone.0278205.r004
DOI:
10.1371/journal.pone.0278205.r005
DOI:
10.1371/journal.pone.0278205.r006
DOI:
10.1371/journal.pone.0278205.r007
DOI:
10.1371/journal.pone.0278205.r008
Language:
English
Publisher:
Public Library of Science (PLoS)
Publication Date:
2022
detail.hit.zdb_id:
2267670-3
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