ABSTRACT
By means of retrograde HRP tracing method, the innervation of the left half of cervical portion of oesophagus in cats was investigated in this study. The HRP-labelled cells were found bilaterally in the retrofacial nuclei, nuclei supraspinalis, nuclei dorsomedialis and ipsilaterally in the dorsal motor nucleus of the vagus nerve, solitary nucleus, nucleus ambiguus, intermediate zone, nucleus retroambiguus and spinal nucleus of the accessory nerve. The distribution of the labelled cells in the dorsal motor nucleus of vagus nerve showed certain localization characteristics. They were more numerous at the levels above and below the obex. The labelled sympathetic preganglionic neurons with long axons appeared in T_1-T_3 spinal segments at the injected side (88.96%) and mainly in T_2(66.45%). The majority of labelled cells were located in the intermediolateral nucleus(95.02%); and the rest were in the lateral funiculus, intercalated nucleus and dorsolateral nucleus of the ventral horn, there were two of preganglionic neurons (i.e. parasympathetic and sympathetic) innervating the oesophagus. The postganglionic neurons were mainly located in the stellate ganglion(61.99%), anterior and middle cervical ganglia, and T_2-T_5 ganglia of the sympathetic trunk, bilaterally. There were some labelled cells in the nodose ganglion and the C_1 to T_5 spinal ganglia(mainly in C_6 and T_2). The ratio between the labelled cells in the nodose ganglion and the spinal ganglia is 2.6:1, which means that the afferent fibres ran predominantly via vagus nerve.