ABSTRACT
The origin of motor neuronal cell bodies innervating heart in the cat was investigated using CTB (Cholera toxin B subunit) as neuronal tracer. The neural tracer was injected into subepicardial layer and myocardium of the right atrium, left atrium, right ventricle and left ventricle, respectively. Labeled parasympathetic motor neuronal cell bodies were found in DMV (dorsal motor nucleus of vagus nerve) and anterolateral part of NA (nucleus ambiguus) of brainstem. Heavier labeled neuronal cell bodies were found in the NA when the neural tracers were injected into left ventricle and DMV when injected into left atrium and left ventricle. These results may provide a neuroanatomical data on origin of motor neuronal cell bodies innervating the heart of the cat.