Facilitation of the swallowing reflex with bilateral afferent input from the superior laryngeal nerve.
To determine the cooperative effect of laryngeal afferent signals on the swallowing reflex, we examined whether afferent signals originating from the left and right superior laryngeal nerve (SLN) modulates elicitation of the swallowing reflex in urethane-anesthetized rats. Mylohyoid electromyographic activity was recorded to quantify the swallowing reflex. The onset latency of the swallowing reflex and the time intervals between successive swallows were used to quantify and compare the effects of unilateral and bilateral electrical stimulations of the SLN. The mean latency of the first swallow and the mean time interval between swallows evoked with low frequency stimulation were both significantly different between unilateral and bilateral stimulations of the SLN. These findings suggest that facilitatory effect of afferent signals originating from the SLN bilaterally increase the motoneuronal activity in the medullary swallowing center and enhance the swallowing reflex.
Division of Oral Physiology, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Niigata 951-8514, Japan; Division of Orthodontics, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Niigata 951-8514, Japan.
Kojiro
K
Takahashi
Niigata University of Rehabilitation, 2-16, Kaminoyama, Murakami, Niigata 958-0053, Japan.
Tomio
T
Shingai
Division of Orthodontics, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Niigata 951-8514, Japan.
Isao
I
Saito
Division of Oral Physiology, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Niigata 951-8514, Japan.
Kensuke
K
Yamamura
Division of Oral Physiology, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Niigata 951-8514, Japan.
Yoshiaki
Y
Yamada
Division of Oral Physiology, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Niigata 951-8514, Japan. Electronic address: kitagawa@dent.niigata-u.ac.jp.
Junichi
J
Kitagawa
D000818:Animals; D003679:Deglutition / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D007823:Laryngeal Nerves / Q000502:physiology*; D008297:Male; D023421:Models, Animal; D010614:Pharynx / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012018:Reflex / Q000502:physiology*
Deglutition; Facilitation; Pharynx; Superior laryngeal nerve; Swallowing