[Study of the pathways of the cat spinal cord using the method of experimental retrograde axon transport of horseradish peroxidase].

Funicular trajectories of descending brain stem pathways in the cat were identified by means of retrograde horseradish peroxidase (HPR) transport. In sixteen cats TH1 HRP injections preceded by a large C6-C7 lesion sparing the ventral or ventrolateral funiculi and by such a lesion sparing the dorsolateral funiculus were made. It was found that the descending fibres from the nucleus locus coeruleus and the nucleus subcoeruleus are distributed ipsilaterally through the ventrolateral funiculus. The fibres from the hypothalamus which descend throughout the spinal cord are located mainly in the lateral funiculus, but some of them also descend through the ventral and dorsolateral funiculi. A diagram summarizing the distribution of the descending fibres from the various brain stem cell groups over the different C6-C7 funiculi is presented.