[Horseradish peroxidase labeled sources of the spinobulbar and spinothalamic fiber systems of the cat brain].

A dense accumulation of horseradish peroxidase (HRP) positive neurons was found after bulbar HRP injections in the ipsilateral dorsal grey matter and in the intermediate zone on both sides. After thalamic injections the labelled neurons were located bilaterally in the ventral part of the intermediate zone. A conclusion is made that cells of the origin of the spinobulbar and spinothalamic tracts are located in the dorsal horn and in the intermediate zone of the spinal cord.