Abstract
The motoneurons innervating the cricopharyngeal muscle of cats were identified by utilizing retrograde axonal transport of horseradish peroxidase (HRP).
HRP was injected into the cricopharyngeal muscle in eight cats, the thyreopharyngeal muscle in four cats and the rostral part of esophagus in four cats.
After injection of HRP into the cricopharyngeal muscle, HRP-labeled motoneurons were found in the ipsilateral retrofacial nucleus and the rostral part of the nucleus ambiguus.
The labeled neurons were most frequently observed through the levels between the rostral part and middle part of rostrocaudal extent of the inferior olivary nucleus.
