Suprasegmentary inhibition and facilitation following administration of tetanus toxin to nuclei of the medulla oblongata (concerning the "starting point" phenomenon)
Sheĭkhon, F.D.; Kryzhanovskiĭ, G.N.
Biulleten' Eksperimental'noi Biologii i Meditsiny 79(1): 24-28
1975
ISSN/ISBN: 0365-9615 PMID: 1111638 Document Number: 88107
Changes in the descending inhibition and facilitation produced by stimulation of the fastigial nucleus of the cerebellum after injection of tetanus toxin into the relay-nuclei of the medulla oblongata were studied in experiments on cats under light nembutal-chloralose anesthesia. The toxin was used as an agent distributing the inhibitory processes. Injection of tetanus toxin into the indicated nuclei was followed by increase in the functional dispatch formed in these nuclei. This was manifested in a repeated increase in the descending inhibition (in case of injection of tetanus toxin into the giganto-cellular nucleus) and the descending facilitation (in case of injection of the toxin into the Deiter's nucleus and the ambigus nucleus), a sharp increase in their intensity to the maximum and their marked lengthening. The data obtained are explained on the basis of the concepts of formation of powerful generators of excitation in the complex relay switching connected with disturbance of the inhibitory mechanisms. The results of these investigations extend the "dispatch station" concept as applied to the supraspinal structures.