title: Two distinct descending inputs to the cricothyroid motoneuron in the medulla originating from the amygdala and the lateral hypothalamic area.
abstract: 1. The retrograde labelling study revealed that there are at least two independent descending pathways from the limbic system to the ventral medulla, i.e., the hypothalamo-medullary pathway and the amygdalo-medullary pathway. 2. The stimulation in the lateral hypothalamic area produced parasympathetic excitation and vocalization response: the recruited motor unit of CT muscle occurred in the late expiratory phase. By contrast, the stimulation at the medial part of the amygdala evoked sympathetic excitation and expiratory braking: the recruited motor unit of CT muscle occurred in the early expiratory phase or in the post-in-spiratory phase. 3. The present physiological study provided further important information on dual innervation of the cricothyroid muscle of the larynx: one motor unit with inspiratory firing is generated in the medulla, whereas the other motor unit with expiratory firing is evoked by a descending input from the limbic system.
authors.affiliation: Department of Physiology, Toho University School of Medicine, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Arita
authors.forename: I
authors.initials: I
authors.lastname: Kita
authors.forename: M
authors.initials: M
authors.lastname: Sakamoto
mesh_terms: D000679:Amygdala / Q000033:anatomy & histology*; D000818:Animals; D001370:Axonal Transport; D007031:Hypothalamus / Q000033:anatomy & histology*; D008526:Medulla Oblongata / Q000033:anatomy & histology*; D009046:Motor Neurons / Q000502:physiology*; D009434:Neural Pathways / Q000033:anatomy & histology* / Q000502:physiology*