THE DISTRIBUTION OF AFFERENT NEURONS IN THE TRIGEMINAL MESENCEPHALIC NUCLEUS AND THE CENTRAL PROJECTION OF AFFERENT-FIBERS OF THE MYLOHYOIDNERVE IN THE RAT
K. Yasuda et al., THE DISTRIBUTION OF AFFERENT NEURONS IN THE TRIGEMINAL MESENCEPHALIC NUCLEUS AND THE CENTRAL PROJECTION OF AFFERENT-FIBERS OF THE MYLOHYOIDNERVE IN THE RAT, Somatosensory & motor research, 12(3-4), 1995, pp. 309-315
Horseradish peroxidase conjugated to wheatgerm agglutinin (HRP:WGA) wa
s injected into the proximal cut ends of three branches of the mylohyo
id nerve in rats: the branch to the mylohyoid muscle (BrMh), the branc
h to the anterior belly of the digastricus muscle (BrDg), and the cuta
neous branch (BrCu). HRP-labeled cells were detected in the ipsilatera
l caudal portion of the trigeminal mesencephalic nucleus (Vmes) and th
e ipsilateral ventromedial division of the trigeminal motor nucleus, e
xcept when HRP:WGA was applied to the BrCu. Morphologically, all label
ed Vmes cells were of the pseudounipolar type. Projections of the prim
ary afferents of the BrMh were observed in the ipsilateral trigeminal
nucleus caudalis, the upper cervical dorsal horns of laminae I-III, an
d the dorsolateral recticular formation (Rf), whereas the primary affe
rents of the BrDg terminated in the ipsilateral trigeminal nucleus pri
ncipalis and Rf. These observations suggest that the role of the affer
ent inputs of the mylohyoid muscle differs from that of those of the a
nterior belly of the digastricus muscle in terms of several functions
associated with jaw-closing and infrahyoid muscles.