CNS innervation of posterior cricoarytenoid muscles: a transneuronal labeling study

The CNS cell groups that project to neurons, which innervate the posterior cricoarytenoid muscles (PCA), were identified by the viral retrograde trans neuronal labeling method. Pseudorabies virus (PRV) was injected into the PC A of C8 spinal rats and after 5 days survival, brain tissue sections were p rocessed for immunohistochemical detection of PRV. Retrogradely labeled mot or neurons innervating the PCA were seen in the nucleus ambiguus and in the area ventral to it. Neurons innervating the PCA motoneurons were found thr oughout the ventral aspect of the medulla oblongata, in the nucleus tractus solitarius, and in the pens. Labeling was present in the midbrain periaqua ductal gray, in the lateral and paraventricular hypothalamic nuclei, in the amygdaloid complex, in the hippocampus, and within the piriform cortex. In summary, the motor neurons that control PCA activity are innervated predom inantly by a network of neurons that lie along the neuraxis, in the regions known to he involved in regulation of respiratory output and autonomic fun ctions. (C) 2001 Elsevier Science B.V. All rights reserved.