A double-labeling method that combines the retrograde transport of horseradish per-oxidase (HRP) with immunohistochemical procedure was used to demonstrate the origins of the central afferents to dorsal motor nucleus of vagus (DMN)and to identify the pe-ptidergic transmitters in these neuropathways in rats.(1) After injecting wheat germ ag-glutinin conjugated HRP (WGA-HRP)into the neural area of DMN, the HRP labeled neurons were found in the following regions:(1) Brainstem: solitary nucleus (n.), spinal tra...