[Further study of the descending sympathoactivating pathways of the dorsolateral funiculus of the spinal cord].
The localization and conduction velocities of descending pathways which activate the different groups of sympathetic preganglionic nerons were studied in the cat cervical spinal cord. Certain evidences have been obtained that the fibres located near the dorsal surface of the dorsolateral funiculi with conduction velocities about 24--29 m/sec. can activate the ventral horn preganglionic neurons monosynaptically. In contrast to previous ideas, the sympathetic preganglionic neurons of the lateral horns seem to be activated not by different but by a single group of descending fibers with the conduction velocity 4--8.9 m/sec and localization in more ventral portions of the dorsolateral funiculus. The transmission from these fibers to the sympathetic preganglionic neurons of the lateral horns occurs in two ways: oligosynaptically (probably, disynaptically) and polysynaptically through a more complicated interneuronal chain. The sympathetic preganglionic neurons with unmyelinated axons, localized in the intermediate zone, for the first time were shown to be activated polysynaptically, probably via the same ways as the lateral horn neurons.
D000818:Animals; D001339:Autonomic Fibers, Preganglionic / Q000502:physiology; D001794:Blood Pressure; D002415:Cats; D004558:Electric Stimulation; D004594:Electrophysiology; D009431:Neural Conduction; D009434:Neural Pathways / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013116:Spinal Cord / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology*; D013997:Time Factors; D014666:Vasomotor System / Q000502:physiology
Dal'neĭshee issledovanie niskhodiashchikh simpatoaktiviruiushchikh puteĭ dorso-lateral'nogo kanatika spinnogo mozga.