Sexual dimorphism in the trigeminal motor neurons innervating the mouse masseter muscle.
The extrafusal and intrafusal muscle fibers in the masseter muscle are innervated by motoneurons in the trigeminal motor nucleus (Mo 5). In the present study, we found that the number of trigeminal motor neurons in the male mouse was significantly larger than that in the female. However, we could not detect any significant difference between male and female mice in the number of sensory neurons in the trigeminal mesencephalic nucleus (Me 5). This is the first report on sexual dimorphism in masticatory motoneurons of mammals.
Maeda
N
N
1st Department of Oral Anatomy, Hiroshima University School of Dentistry, Hiroshima, Japan.
Sugiyama
H
H
Suemune
S
S
Wakisaka
H
H
Niida
S
S
Ogata
K
K
Miyata
K
K
D000818:Animals; D005260:Female; D008297:Male; D008406:Masseter Muscle / Q000294:innervation*; D051379:Mice; D008813:Mice, Inbred ICR; D009046:Motor Neurons / Q000502:physiology*; D012727:Sex Characteristics; D014278:Trigeminal Nuclei / Q000166:cytology*